corrosion of electrical contacts

Jul 20, 2016 3 Replies

I got a complete wiring harness for a 20-year old car from the wreckers. When I pulled the relay box apart, I noticed that all the relays had corrosion on one terminal only - the same terminal. Is this a common phenomenon? These were the bog standard Bosch automotive relays with 6 mm wide terminals.


Was the corrosion in pin 30 (battery +)?

Pin 30 on relays is the one that would go to the battery +12V supply and is sometimes brass where the other terminals are plated or the actual terminals going onto pin 30 are brass so electrolysis may have occurred and corroded the terminals especially if they were in a damp location.

Join the Discussion

Have something to add? Share your thoughts — no account required.

Didn't find your answer?

Ask the community — no account required