Blowing relays.

[Youssef]

Ok I have one to pick you guys brains, so let me start at the beginning. A couple of days ago I parked up somewhere for a few minutes and when I came back and started the car I noticed the windows didn't work. So i checked the fuse and it was fine and pulled the relay. Once I put the relay back the windows started working again.

A few days later I went by a "friend" of mine. So when I was leaving by her I jumped in the car started it and noticed the windows stopped working again. I also noticed the ac was not blowing cold, the headlights did not work and the oil pressure guage I have was reading lower than normal. Even while driving the needle does not cross 20 psi now. All these things worked fine on my way by my friend. I went and switched around some relays and got everything except for the oil pressure reading working. Got home that night and everything was still fine, drove to work the next day with everything still fine.

Then when I jumped in the car in the evening to head home the head lights and the ac once again stopped working. Swapped over the relays again and got them working. Got home and started checking around for shorts. Found something and took care of it. But the next day same thing, drove to work fine. In the evening go to start and ac and headlights not working. Relays seems to be blowing in the AC and headlight spots too. Oh did i mention the oil pressure reading is still low.

I should mention that the car seems to be driving fine otherwise and NOTHING was done to the car anytime recently except to wash it and clean the interior earlier in the week. Also no fuses are blowing only relays seem to be affected. Can anyone shed some light on this head scratcher.

[The Vee]

When you washed it, did you do the engine bay? Just wondering if you have any water ingress probs.

[Youssef]

Nah it was just a general wash, the outside and the inside was vacumed and wiped out. I did everything myself so I can say for sure under the hood was not washed. I thought about that one already. Any other ideas? A big question for me is why is it the relays being affected and not the fuses. They are all fine.

[Nick Mann]

Could it be a sticky relay? Everytime you remove it and put it back in, you knock it enough to allow it to move again?

[mike74]

Try cleaning the contacts on the affected relays with emery paper & spray some WD40 into the 'female' part it plugs into. They could be slightly gummed up & not making a good connection. Also check that they are a good, tight fit in the plugs too. If they're quite a loose fit, take a small screwdriver & see if you can close the female crimps a bit to make them tighter. It could be a dodgy earth somewhere too...happy hunting & good luck!

[Turbo_Steve]

Agree with the above - first of all clean the contacts.
If that fails, try opening your relays up carefully and cleaning the contacts internally - it's possible they are sticking.

Do you have a volt-meter on the car? If your alternator is "over volting" then your fuses will remain okay, but your relays (and other bits and bobs) will run too hot, allowing them the stick.

As Nick says, have you tried doing each Relay individually to ascertain which one is the suspect?

[Youssef]

What if it's a case of the alternator "under volting". A couple of months ago my alternator died on me and I had to end up using one from a different model galant that was rated at 80 amps instead of 100 amps. So once the rpm drops below lets say 900 rpm the battery light starts to come on. I didn't mention this before because I didn't want people to just blame the alternator and also because I have had it installed for atleast 3 or 4 months without any issues. Plus once you are driving the light doesn't come on at all. And the relays seem to be affected when the car is off not when it's running.

[Gly]

amps wont matter, unless you have all of you electrics going + more
80 amps is enough for a fairly standard (electris wise) car,
80/100amp is the diff between warm/cold spec


the batt light coming on is an issue,
i would be checking the voltage while the car is off/idle/reving at 2-3k

let us know the result

/edit

check all the plugs into and from the alternator, and where the power feed bolts to the fuse box.

[martin_y]

Couldnt bad earthing cause all these symptoms? When it happens again put a jumper cable from - on battery to the body and lets see if the problems go away then.

[Turbo_Steve]

Bad earth tends to throw up a lot more (and weirder) symptoms, Martin, but it's worth a try.

[Youssef]

After some probing I am leaning towards getting some other relays and trying, when I take out the relays and tap it something that looks like sand comes out of it. Some are worse than others. Also I notice that if the lights don't come on and I flick the switch on and off a few times it starts to work. I'm wondering if it's a matter of bad or sticking relays. Thanks ofr all the advice and the really quick responses.

[Turbo_Steve]

SAND comes out!!? Sounds like they've been baked. Given they're only a couple of quid, you might as well try some more and see if it helps.

You DEFINITELY need to get a multimeter on the battery with the engine running and check your voltage, though - if your alternator is broken it will end up frying something important.