General Automotive Relay diagrams?

[Kansei]

I'm trying to diagnose a lighting issue on a friend's 91 Volvo 940SE Turbo and the lighting relay is a bit complicated. First, it's a double relay. One has 6 pins, the other, 3.

Here's what it says on the side of it, there isn't a diagram:

56b - 10amps
31
56
56a - 20amps
30
81a
------------------ above is upper relay, below is lower relay.
56a
56
56b - 6amps

I need to know which pins I need to test across. I don't even know if it is a normally open or normally closed relay, but I guess I'll find out.

I know the ones with currents listed are the high current pins, but I don't know which are the ones I need to power to switch the relay on and off for testing.

He would just replace the relay but it is over 100 dollars >_<

 

[chuyler1]

Maybe this will help...

http://www.bcae1.com/relays.htm

 

[OBJunior]

You could use an ohmmeter to find the NC contacts. Apply a 12 V test lead to the contacts one at a time and listen for it to click.

 

[Kansei]

Apply a 12 V test lead to the contacts one at a time and listen for it to click.

that's what I figured I would try with it. Thanks

 

[OBJunior]

I forgot that you'll need to find ground before you can test the contacts with the test lead. You should be able to tell whats what by checking the wires colors. I believe ground in a car is black, I'm not sure though. Its green in my field. Just put the relay back in and take note of what wire goes where.

 

[Kansei]

I forgot that you'll need to find ground before you can test the contacts with the test lead. You should be able to tell whats what by checking the wires colors. I believe ground in a car is black, I'm not sure though. Its green in my field. Just put the relay back in and take note of what wire goes where.

I cannot get to the other side of the relay panel, as least from what I could see, without removing the centre console from the car. Damn the swedes.

I'll give it a look when my roommate gets back from crew practice.

I think he has a wiring diagram of the car down in the garage so I'll see if that has it first.

 

[ssinstaller]

There really isn't alot to go bad inside a relay. If you can get the cover off try and reheat the solder traces on the board, alot of times the traces will crack slightly from the arc whn the relay trips--I fixed about 20 of honda's$85.00 main relays like that.

 

[Kansei]

Thanks for that info. My roommate went back to PA for the weekend today so I won't be able to try anything until next week.