Which Relay is Which?, Highbeams won't switch Options

[ThinAir]

This is a 73, 2.0L. After changing the electrical part of my ignition switch, I think I must have shorted something because I've got a strange high/low beam behavior.

When I turn on the headlights they are on highbeam. I try to switch them using the stick, but nothing happens - no click or anything. I suspect that I blew the highbeam relay.

So, which relay is which? I searched and found a topic that says the highbeam relay is the silver square one on the top of the fusebox. Is this correct? If so, would this part at Pelican be the replacement? 141-951-253-B-M5206

I can find lots of resources that identify which fuse goes with what, but I can't find anything for the relays on the top of the fusebox. I have 3 round ones in a row, then the square one, and an empty round one above that. What do they go to?

Here's a rough diagram, looking from the top of the fusebox as if sitting in the driver's seat:

O - Empty round relay
O O O [] - Square, silver relay
| | |
--------------------------------- 3 Round relays

So what do these go to? The picture in my Haynes manual doesn't have the empty round socket and it thinks one of the 3 round relay spots is used by a buzzer, so I doubt that it applies at all.

[gklinger]

Ernie, it's this one: 111-941-583-M155

[ThinAir]

Thanks, Garry. Of course it would be the $29.95 part and not the $5.00 part.

I'm still wondering about the rest of the relays. I don't know why I bothered with trying to make a diagram (especially since the spacing got all messed up). Here's a picture. What are the different round relays for, especially that empty socket in the upper-right corner?

[lapuwali]

The high/low beam relay is the cubical one on the left. Easy to tell since the high beams are white wires, and the low beams are yellow wires.

Figuring out what the others do is a matter of following the published wiring diagrams. Black wires are power switched by the ignition, as are red/white wires. Red wires are battery (unswitched) power. Browns are grounds. Knowing that, look for the two wires not in the above collection, and that will be the "switch" and the "switched" wires that connect to the dash switch or the thing being switched. These two will tell you (with a diagram) what that relay does. Colored wiring diagrams can be found on Pelican's site. You can generally use the '73 diagram for all of the later cars in most respects (there are some differences, but not too many). The '70-'72 cars are somewhat different, but there are dedicated diagrams for those cars on PP already.

[greglepore]

Before you replace the relay, check for power at the terminals that are controlled by the h/b switch-its more likely that you disturbed one of the connectors at the base of the plastic housing around the column-the relay simply goes from n/c (low) to the n/o when you pull the stalk- it'd be hard to burn it out.

[ThinAir]

Turns out that the h/b relay is not the problem. I borrowed one from another car and it didn't fix it.

I've also learned that when the headlights or parking lights are not on and I turn on the left blinker I do not have normal blinker function. Instead of the middle rear bulb flashing, the side marker and right bulbs are flashing dimly and the front blinker isn't very bright either. From my experience this is an indication of a grounding problem and that the positive side of one of the circuits is functioning as a ground.

Since the only thing I did before this came up was to swap the ignition switch, I'm guessing that this is where the root of the problem is. Like greglepore mentioned, I've probably got a ground that isn't making contact at the point where the wiring stack leaves the stearing column and connects to the rest of the harness.

Did I mention that I hate automotive electrical problems? (IMG:http://www.914world.com/bbs2/html/emoticons/headbang.gif)

[Hammy]

I believe the upper right empty relay is for the door buzzer? Though I may be wrong.