can relays start acting up? or are they either good OR bad?

(hunting down some electrical glitch....)

Sure, its possible. Relays themselves are very long lasting, and rarely have problems,but they can occur. What usually happens with them is that they can get moisture inside them, and it starts to corrode the contacts inside them, and can cause problems. This is esp true with relays under the hood.. I work with relays everyday at my job, and i have rarely found any bad ones..but there have been a few..

I understand that, but what i meant is, can they act up but work fine some of the time? or do they just plain work until they go bad and stop working?


thnx for the quick reply :)

I'd say it's possible, but not very likely. You never know with electrical stuff though..

I am a manufacturing engineer at a company called Leach international, and guess what what we do is make relays for military, aerospace and light rail.
your question regarding the relay, a relay is just an electro-mechanical switch. I have seen several cases where they work when they are cold, and when energized for a little while and they warm up they can start working intermittently or not at all. there are several reasons why this happens, but they are not really that important for your question. yes they can work now and not later and then work again later.
lates
james

ok, so how bout this... could a fuel pump relay cutout while driving, causing the car to die b/c of no fuel?

If you have both fuel pumps wired to the same relay as far as feed power, I say yes. I've had a relay go bad on me before in the same spot. Fortunately, it did not occur while driving and I didn't have both pumps' power supplied by the same power feed through the bad relay.

it is possible for a relay to energize and then after some time drop out due to a temperature rise. this is a very likely possibility, but if it was to drop out then you can test it for continuity when the car is on. a way to test this is to take the relay out, connect the coil terminals to a 12 volt source and verify continuity through the poles. Then let it sit in this energized state for a little while and come back and test it for continuity again. the relay should still show that it is closed, if it ain't then you have a damaged intermittent coil in the relay.
lates
james