I bought a pair of electrically heated motorcycle gloves: which don't work There is a lead which connects to the battery. In the live lead is a fuse, the lead runs to a coaxial connector which is brought out in front of the seat. I measure the voltage there as 14V with the engine running. An extension lead runs from there and splits into two one for each sleeve terminated with another coaxial connector on each arm. The voltage at the sleeve end is also 14v. I measure the resistance of the gloves as about 10 Ohm each if I connect the glove to the power connectors they don't heat up.
It sounds like the supply wiring has a high resistance connection that supplies enough current to make a volt meter work, but uses up essentially all the voltage when the glove resistance is connected in series with it. You may need to figure out how to measure the voltage drop across various parts of the wiring, while the gloves are connected, to find where the bad connection is.
Excluding the possibility that there is a thermostat system and it just wasn't cold-enough when you tested them:
- You could try powering the gloves as directly as possible, from a 12V battery or DC power supply (with an ammeter in series with the battery or supply, if possible). If this test works, the gloves are OK and the wiring or connectors from front of seat to aft is the problem (OR, your system can't push enough amps at 14v, for some other reason).
- You could try powering a test-resistance and an ammeter in series, using the connector in front of the seat. Your two ten-ohm gloves would be 5 ohms when in parallel, which should draw 2.8 Amps, max, from a 14V supply (assuming that the supply can handle it). So a test resistor of 5 ohms would need to be rated at at least 39.2 watts or more. Or, you could use two 20-Watt 10-Ohm resistors in parallel (or four 10-Watt 20-Ohm Rs in parallel, or eight 5-Watt 40-Ohm Rs in parallel, etc, etc). Note that the resistor(s) might get too hot to touch, fairly quickly. If this test works, i.e. you get about 2.8 Amps, then either the gloves OR the forward wiring/connectors are the problem. The Radio Shack store, here, still carries a few power resistors in stock (Or buy an older-type TV at a garage sale and look inside. But use caution, since capacitors and picture tubes can still have high voltages on them.). Even if the test resistance is not exactly 5 Ohms, you should still be able to get some idea of whether it's "in the ballpark" or not.
I ride my motorcycle during the winter and had a few of these problems with my electric suit. I would see voltage and the suit would ohm out correctly, but no heat. The fault was light corrosion due to all those times I rode in the rain. If you have light emory cloth, it can help give you clean connections.
Hopefully, the gloves were made for your suit and have the same sized barrel connectors.
The other problem I have is the copper strands eventually breaking due to flexing. Solder and heat shrink is what I use.
Had my electric suit for 5 years and its worked well down to 0F when riding, or at -20F in the ice cream freezer at work! Good luck!