That may be normal: Notice that it starts charging at about 1200 RPM.
Oh-oh. Was this a rebuild, or an exchange? If exchange, was the pulley diameter the same as the original? Methinks you should check if it's the correct diameter pulley (including the belt depth and fit).
Nope. If it's charging normally at higher RPM's, and it's not over charging the battery, it's probably working normally. Minimum charging RPM is set by the pulley diameter ratio, typically 3:1 for a gasoline engine. No clue what it might be on a diesel. The idea is to set the RPM so that it barely charges at idle, where the added load of charging the battery and running the lights does not put an excessive load on the engine causing it to stall at idle or have difficulties starting.
The regulator is inside the alternator and possibly looks something like this: Before attacking, you might want to pull the alternator and drag it down to an auto electric shop and have it bench tested. Or do it in the forklift:
What problem did that solve and what problem are you trying to solve here? Sounds to me like it's working normally. If it doesn't charge at idle, does it need to charge at idle, such as it might need to charge the battery just after starting? Does it deliver any current when you turn on the lights?
Note: The dashboard ammeter might be giving you a false impression that the alternator is not charging. It's connected to the positive wire going between the battery and the alternator. The various loads in the forklift go to the battery. If the engine is at idle, the battery is fully charged, and you have perhaps a 5 Amp load (headlights), if the alternator is delivering 5 Amps to the lights, the meter will read zero because the battery is not delivering any current or being charged.
Basic test. Put an inductive ammeter: on the battery (not the alternator) positive wire and see what it's doing. At idle, it should barely charge (less than 5A). Turning on the lights, will make it charge more. Revving the engine should charge even more, but only if you have a battery that needs charging. If the battery is fully charged because the forklift has been running for a while, you won't see much charging current. Moving the inductive ammeter to the alternator positive wire should should what the alternator is doing.
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Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
It was an exchange. I did not check closely when it was exchanged (my guy went to that shop, not me).
What I know is that the pulley that I have right now is the smallest practicable pulley.
Well, I know that it does NOT charge at idle.
I know that by simply measuring voltage on the battery. It is about
11.76 volts when at idle. Goes up to over 13 volts if I push the gas pedal.
I do think that I have a good understanding of it using the multimeter.
The problem was exactly the same, the other forklift also had a DD53 and the replacement alternator did not charge at idle. I was able to make the pulley diameter smaller on a lathe and that helped.
Here, the pulley diameter is already small and even smaller diameter will ruin the belt.
It definitely needs to charge at idle.
I was looking at changes in battery voltage.
At idle, the battery voltage is exactly the same as when the engine is off.
I just bought an ac/dc clamp ammeter, it might help me in the future, but I do feel strongly that the DC voltmeter is telling me all I need to know.
Oops. Y're right. The load is on the alternator side.
The problem is still there with the correct wiring. If the alternator is providing all the current needed by the load, the battery provides no current, and the meter does not indicate any drain. Turn off the engine, and the meter will indicate a drain from the load.
Thanks for the correction.
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Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
The reason I mentioned the pulley swap is that's what happened to me in the distant past when I bought an exchange alternator. The smaller replacement pulley diameter was sufficiently different that the vehicle charging system to act strangely. Over speeding the alternator blew up the regulator several time. Then it blew up one of the diodes, I got suspicious and checked the operating AC voltage to the diodes. Too high. I was on my 3rd replacement alternator, all with undersized pulleys, when I found an identical model Dodge D50 diesel and measured the pulley diameter. Swapping for the correct pulley fixed the problems.
Incidentally, I also had oil pressure problems from the undersized pulley. The oil pump was attached to the back end of the alternator, resulting in excessive oil pressure. That blew out several oil filters and one pressure regulator valve. That problem also went away by using a larger pulley diameter.
In my days in the 2way radio business, when tube type mobile radios drew considerable power in receive, it was imperative that installations that spent considerable time at idle could also charge at idle. Public safety and delivery vehicles were prime candidates. At the time bigger alternators, with smaller pulleys were a common solution. I wasn't involved in the conversions, but did notice a fair number of squealing fan belts when the vehicles arrived for service.
If your alternator was an exchange, I would at least determine what is the correct pulley diameter (and cross section for the belt).
Ummm... I know this is too obvious, but by chance did you check for a loose and slipping fan belt? That might explain the lack of charge at idle. Also, if the pulley wedge angle does not match the belt, it will slip. How about the belt contact angle on the smaller pulley? My guess(tm) is about 120 degrees minimum or it might slip.
Ok. You have an optical tach handy. At what RPM does the alternator start to charge? I'm trying to determine if it's marginal or broken.
11.76V presumably measured between the battery terminals, is a dead battery. Lots of SoC (state of charge) charts available: This one looks good:
11.76v is 30% of full charge. The alternator should be furiously charging such a depleted battery. However, don't assume that it's dead or dying. It might be that the charging system has some kind of failure. Try charging it back up with an AC powered battery charger and see if things start to work more normally. If you have removable caps for a flooded lead acid battery, verify the SoC with a battery hydrometer.
Assumption, the mother of all screwups. Also, test your assumptions, which you may have noticed is my method of troubleshooting.
Do you know anyone else that has a similar fork lift? There should be some forum online where you can obtain a consensus. In other words, are your two fork lifts the only one's with the problem? Is it a common problem? Is it inherent in the design of the forklift? Do other fork lifts of the same model charge at idle. Are there any factory modifications available? I wish I could answer these, but this type of survey is too time consuming. Googling for forklift forums: etc...
Yep. See my comment above on the squealing fan belts in the old vehicles which had modified pulleys.
How much charging current would you guess might be required at idle? That will tell my how far up the RPM curve you will need to spin the alternator. If you could disclose both pulley diameters, I can calculate the required engine idle RPM. If too high, it might not be possible. Let's use this curve until something better can be found:
Bad idea. You should see a change when revving the engine, but you can't use the voltage as an indication of charging current. For that, you need an ammeter. Also, the voltage does change with temperature.
That's a good indication that it's not charging at all. At idle, most charging systems will produce 13.8 to 14.3 volts with no lights or accessories on (although some may charge at a slightly higher voltage depending on temperature, engine RPM, type of battery, and the battery's state of charge).
11.76V is MUCH too low.
Many clamp on ammeters do NOT measure DC current. As I mumbled previously, voltage is not a good indication of what's happening, although it does offer some clues. In this case, you seem to be ignoring an obvious clue. 11.76V is MUCH too low for proper operation. Assuming the battery is good, something else is seriously wrong. I can't tell from here, but my sense of smell says it's a blown fusible link, or rotten terminal connection on the alternator.
Also, it would be very helpful if you would kindly supply numbers. By numbers, I mean measured voltages, measured currents, the maker and model of your clamp on ammeter, the maker and model of your alternator, the maker, size, and model number of your battery, pulley diameters, and so on. The quality of the answers that you get will be directly related to the quality of the information that you provide. Numbers always are a big help.
Good luck.
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Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
You MAY be able to modify the alternator to get it to charge at idle. The regulator may be dropping out at low voltage. Possibly putting a resistor across the regulator circuit might cause it to deliver a little current even at a low voltage.
But, the real problem may be that the new alternator is not designed for running off this Diesel engine. Depending on the engine's idle speed and the crank pulley diameter, it may not get the alternator spinning fast enough. Possibly the original alternator (do you still have it?) had a different rotor or stator winding pattern to accomodate this. If you still have the old alternator, you might be able to replace the rotor brushes or rectifier diodes to get it to work again.
1250 RPM sounds pretty low. Most small cars have engines that idle around
800 - 1000 RPM, and with a 3:1 pulley belt ratio, the alternator would be spinning at least 2400 RPM at idle.
The pulley ratio is not always exactly 3:1. For example: Looks like between 1.85:1 to 4.21. I would not speculate as to the alternator RPM until the OP delivers the actual pulley ratio(s) on his unspecified model forklift(s).
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Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
I have been through shit like this and I TINK I can tell you what to do.
Mrchanical regulators that use a relay can develop a fault which mak3s the spring stronger. Many of these have a screw setting to set the voltage, but the spring is too strong to allow the current to flow to the field of the alternator (or generator).
The cure is to reduce the spind pressure, and that is done by one of two wa y. One, if possible is to bend the tang to which the spring is attached to reduce its applied pressure. The other way is to overextend the spring to d o pretty much the same thing. In each case, you will have to adjust the con tacts to prevent overcharging.
Some of these regulators were SPDT, and the ideal was at idle the points wo uld be closed at idle, putting the alternator or generator into full output mode. However it didn't always work out. Q@hen the RPMs increased, the con tacts of the relay were supposedd to pretty much vibrate. This of course re duced their lifespan and then they had to be replaced. And plenty of people who did not know electronics errantly replaced many alternators when what they reall need was the regulator. Not all the time but enough worth mentio ning. I am from a car family, I can BUILD a car from scrap metal.
Take the cover off the regualator and do not f*ck with that screw adjustmen t. Look where the spring attaches and bend the tang to reduce the pressure.
If it has an electronic regulator, you either need brushes in the alternato r or simply to up the idle a bit. It really doesn't cost alot to up the idl e. Someone mentioned a smaller pulley. well that might work but then when y ou crank it up to do real work it will wear and tear on the alternator by o rders of magnitude.
Actually the easiest way out of this is to just crank up the idle speed unt il the thing actually charges and be done with it.
I got a lifetime of experience with shit like this and that is my recommend ation. Take it or leave it. Just turn the damn idle up and forget it.
On Thu, 23 Jun 2016 19:04:04 -0700 (PDT), snipped-for-privacy@gmail.com wrote:
Huh? That last time I saw a mechanical regulator was on a generator. There were a few alternators with mechanical regulators, but they never worked well. Ever since the 1960's, alternators had electronic regulators that were usually located INSIDE the alternator housing. I did have some kind of alternator that I installed in 1960 Ford Falcon that had an external solid state regulator.
Except for the engine and running gear, I've helped build vehicles of sorts out of scrap metal. You can see the modern incantation on New Year's day as the Cal Poly Rose Float. Powering 25,000 lbs of scrap metal and soaking wet flowers down the road is not simple easy: I was involved between approx 1969 and 1971. Cal Poly was famous for animation on the floats, which was mostly mechanical until 1967, when I helped switch to electrical using mostly windshield wiper motors. Eventually, it morphed into a monitor like water canon, which I won't explain. The problem was with all the electric motors running, electrical power at idle was at a premium. It wasn't just electrical power, but also hydraulic power, all originating from a 4 cyl tractor engine of dubious origin. We could rev the engine, but that produced too much smoke and noise. So, we introduced a pony engine specifically to run the hydraulic and electrical stuff thus allowing the vehicle engine to stay at near idle most of the time. After a few disgusting failures trying to use junk yard alternators of the era, I moved up to bigger is better alternators. A few years after I graduated, the various electrical system was powered by three alternators and tractor batteries, each running part of the electrical system and animation. Automation had progressed from me flipping toggle switched, to cams, to a rats nest of timers, to PLC's, and finally to computah control with solid state switches.
I rode inside the 1971 float acting as the electrical animation controller, flipping switches in the proper sequence. I also managed to be located under one of the numerous hydraulic fluid leaks and finished the parade soaked in hot hydraulic fluid.
The kid in the bed would raise himself, rub his eyes, the toys would bounce around, and then he would lower himself back onto the bed. The problem was that the kid weighed far too much for the hardware we used. About 2 weeks after the parade, we returned the float back to Pomona, where it was shown on campus, and later disassembly. During disassembly, we discovered that some of the few bolts holding the kid to the hinge assembly had sheared half way though. I was presented with one of the bolts, which I still have somewhere. I can scan some old photos and post them if you want to see vehicular scrap metal in action. Oh, found one photo: That's me at work. The main hinge is just above my legs. The 4 bolts and leaky hydraulics are at various points above my head.
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Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
I never saw any alternators with mechanical regulators, so I'll take your word for it that they existed. I also didn't have any luck using Google to find alternators with mechanical regulators.
I still think you're off on the date of introduction for internal regulators. The one's I saw were based on ceramic substrate hybrids such as this one from Delco: I couldn't find a photo of the insides of a hybrid voltage regulator. It's a ceramic substrate, with screened and fired resistors on the substrate, conductive paths, and components attached with reflowed solder. It's much like a modern SMD PCB, but using a ceramic substrate instead of G10/FR4 board.
Prior to these hybrids, regulators were external for a multitude of reasons. They were to big to fit inside. They didn't handle the heat very well. Unsecured component leads would vibrate and eventually break. Threshold adjustments were necessary with different alternator to battery wiring schemes and grounding derangements. Etc. Mounting the regulator externally allows for a lower temperature location, potting, and adjusting. When hybrids arrived, they solved all of these problems. They were small enough to fit inside, the parts were nailed down to the PCB, and they handled the heat MUCH better. Internal was also much cheaper.
However, the various manufacturers did not want customers to be playing with regulator adjustments. One mistake, and all the black boxes will go up in smoke. So, the regulator had to be an integral part of the alternator, and designed for the specific wiring and ground derangement of the vehicle. Variations in positive lead resistance was cured by adding a sense wire to the battery. Variations in ground resistance were reduced by adding a heavy grounding cable to the frame, so that it wouldn't rely on the electrical resistance of the frame. However, they also couldn't compensate for variation in charging required by different size batteries. In other words, the regulator had to be designed for a specific vehicle and was NOT universal.
Over the years, the situation improved, slightly. The problem was that vehicle manufacturers wanted to take advantage of improvements in charging technology, such as 3 stage charging, AC de-sulfidation, SoC (state of charge) monitoring, etc. However, with the regulator located inside the alternator, and the battery at the end of a rather long extension cord (wire harness), such things were not going to work well. So, todays alternator is largely the same as what you saw in the 1980's. They're all a single bulk stage charging system, with no ability to do 3 stage charging (bulk, absorption, float). It could be done if manufacturers would go back to an external regulator, but that's unlikely.
Things are very different in the marine electronics biz. There's no such thing as a "standard installation" in marine electrical and electronic wiring. So, the charging system has to be sufficiently versatile, flexible, and adjustable to handle just about anything. For example, you can get an alternator that offers a bolt on "internal" regulator of sorts, but which can also be remote mounted, and is adjustable: Exotic systems, such as those required by having two engines are accommodated by combiners and charge controllers. For example: Notice the external regulators and 24V system. I believe that there are 3 stage charge controllers available, but I couldn't find any with Google.
Now, back to the soft charge you mentioned. That is intentional as you not. However, it's a side effect of the isolation diode installed in series with the common point of the 3 rectifier diodes. It's only purpose is to prevent the battery from discharging through the stator windings when the engine isn't running. The problem is that the manufacturers originally used the cheapest power diodes that they could find, which had a rather high forward voltage drop. The result was like putting a resistor in series with the battery, which eventually resulted in a rather soft knee on the charge curve. This allowed for larger variations in frame ground resistance, which was deemed a good thing, so it became a permanent feature.
Incidentally, much of my experience with automotive electrical systems came from installing tube type mobile radios in commercial and public safety vehicles in the 1960's and 1970's. The radios were big, heavy, ugly, drew about 5 Amps in receive, and sucked 20-60(?) amps in transmit. (The photo is really a 160D and is missing the Carter "SuperMotor" motor-generator). Anyway, replacing the alternator and regulator with something much bigger was standard practice in new mobile radio installs. For a short time, I also worked for a Ford dealer while attending college and did automotive electric. Both of these required that I learn something about automotive electrical systems. Later, I ended up designing marine radios, which exposed me to marine electrical systems.
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Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
pulley size is by design ...if the unit installed is for the system then the pulley is designed so.
alternators n generators connected directly to RPM display an output curve directly related to RPM.
so when the maker writes unit's power output is 120 amps (Ford) what is described is the unit outputs 120 at 60+ mph.
this in reality doesn't cover radio esp 400 watt rig/lights/AC in slow go commuting with extensive idle...in cold weather. That 120 doesn't charge the batt
My van has a 200 AMP with an Odyssey Bat. With everything running at 65 mph, 200 amps doesn't charge the batt. Gotta shut off the stereo for a charge. Over uh 4-500 miles. Runs down slowly.
so if you have a problem with this either a new batt or a higher output alternator and a complete check on wires and connectors cleanuo is in order.
the system is victim to the fabled cost accounting design team. So many people do this and that cost this so we come out ahead if we squeexe $$ from the charging system.
hard on batteries...sell more batteries
hard on alternators....sell more alternators...everyone in full term vehicle use buys 2 or 3 alternators and the old ones are rebuilt n sold for 3x the profit.
the practice prob kills a coipla hundred people a year with total damages I guess 10-20 mill ?
My cousin used to rebuild his own. (we are/were a car family) Before the da ys of the built in regulator all you had to do was change the brushes and c lean the armature (is that the right word ? been a long time) and you were done. You knew if the diodes were shorted because there would be smoke. It was very rare for the diodes to go bad. There was some kind of trick to hol ding the brushes in for reassembly, paper clips through some holes.
I knew a hillbilly mechanic who had a quick test, when it is charging there is a noticeable magnetic field right at the back of the alternator where t he shaft is. Just took a wrench to it, if it pulls there is field current. If there is field current and no smoke, 99 % of the time it is charging, or at least working. Because of regulation that field will be strongest at id le.
Also, older cars charged at about 14.4 volts. Any more and you had to keep putting water in the battery. The newer cars with their complex electrical system pulling alot more and the sealed batteries you want to see them char ging at least at 15.2 volts. Some newer cars actually pull more current to run than to start.
o commuting with extensive idle...in cold weather. That 120 >doesn't charge the batt "
I am surprised more people do not have problems when forced to dive in rush hour traffic, err actually I mean park in rush hour traffic on the highway . I used to work cross town and 23 miles frequently took me an hour to get home. After an incident I told them I was not going to be in a rush to get there, and I got a raise to make up for it but the quit time was always the same. I tried to convince them to stay open another hour or two but they d id not want to do it. So I left a five. Then I got into the habit of stoppi ng at a local bar out there to kill that hour and I got home at almost the same time.
But they really have beefed down the alternators in cars. It is so bad that they have in the instructions "DO NOT INSTALL THIS IN A CAR WITH A DEAD BA TTERY". It cannot handle a dead battery like in the old days. Hell we used to just change of fix the alternator, jump start the car and let it run for a twelve pack of beer then it was fine. Can't do that no mo.
That is because the bean counters now outrank the engineers. Let's put it t his way, my sister is throwing out a three year old refrigerator. Realize t hat the 30 year old refrigerators are mostly still running.
Yup, Dodge v Ford was the worst thing to happen to this country. But then I imagine it is the same all over. If you could find companies that are not publicly traded you might get quality product, but nobody wants to use thei r own money for startup. Plus they ALSO want to make as much money as possi ble for the least work possible.
days of the built in regulator all you had to do was change the brushes and clean the armature (is that the right word ? been a long time) and you wer e done. You knew if the diodes were shorted because there would be smoke. I t was very rare for the diodes to go bad. There was some kind of trick to h olding the brushes in for reassembly, paper clips through some holes.
re is a noticeable magnetic field right at the back of the alternator where the shaft is. Just took a wrench to it, if it pulls there is field current . If there is field current and no smoke, 99 % of the time it is charging, or at least working. Because of regulation that field will be strongest at idle.
p putting water in the battery. The newer cars with their complex electrica l system pulling alot more and the sealed batteries you want to see them ch arging at least at 15.2 volts. Some newer cars actually pull more current t o run than to start.
go commuting with extensive idle...in cold weather. That 120 >doesn't char ge the batt "
sh hour traffic, err actually I mean park in rush hour traffic on the highw ay. I used to work cross town and 23 miles frequently took me an hour to ge t home. After an incident I told them I was not going to be in a rush to ge t there, and I got a raise to make up for it but the quit time was always t he same. I tried to convince them to stay open another hour or two but they did not want to do it. So I left a five. Then I got into the habit of stop ping at a local bar out there to kill that hour and I got home at almost th e same time.
at they have in the instructions "DO NOT INSTALL THIS IN A CAR WITH A DEAD BATTERY". It cannot handle a dead battery like in the old days. Hell we use d to just change of fix the alternator, jump start the car and let it run f or a twelve pack of beer then it was fine. Can't do that no mo.
this way, my sister is throwing out a three year old refrigerator. Realize that the 30 year old refrigerators are mostly still running.
I imagine it is the same all over. If you could find companies that are no t publicly traded you might get quality product, but nobody wants to use th eir own money for startup. Plus they ALSO want to make as much money as pos sible for the least work possible.
2 power units, one a generator and one a Ford 120amp alternator burned dow n feeding lights, an inverter to laptop over forest roads at 7-12 mph.
The system's design is capable at rush hour with a good battery otherwise s ales will suffer. many comment on the occasional Dodge Groups product parke d roadside with electrical problems.
My 1963 Pontiac Catalina, and my 1966 Pontiac GTO both had firewall mounted, mechanical regulators for their alternators. I had a 1968 GMC Handivan that used the same regulator. My 1973 Chevy Stepvan (Union City body on a school bus or motorhome chassis) was my first vehicle with an internal regulator. I used to rebuild bad alternators, rather than replace them. Brushes, bearings and diodes were easy to find, and affordable to rebuild the existing alternator.
I had a 'Barney Fife' type tell me to shut off the GTO in the middle of the road, because the lights were dim. I told him that I wouldn't be able to restart the engine, if I did. I told him that I had just bought a new regulator to repair it, and that I was only 15 feet from my driveway.
The stupid #$%^&* pulled his gun on me and screamed that he was going to kill me, if I moved the car. My dad was home, and heard him. He asked what was wrong. 'Barney' told him that he was going to shoot me because I wouldn't shut off my car. Dad went back in for one of his guns and told him to leave, or the sheriff would be called to arrest him, since the Township police were not allowed to do more than write traffic tickets. 'Barney' fled the scene when the neighbors started coming outside, and heard him making more threats. He was a bad ass, with no witnesses, but a real coward when the porch lights started coming on.
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