Wiring Gremlins

[67RS]

Ok I'm chasing my tail and I'm getting frustrated; I need help.

Here is the deal. I added relays to my headlights. One for high beams and one for low. I used the original power lines to trigger the relays and I came off of the horn relay for the high side to run the lights. No problem. The lights worked fine this way for a year. Last week I bought a painless wiring kit to, finally, hook up my headlight doors and thats where the problem started. Now the doors open and the lights come on but if they are on for more than a few seconds they won't shut off and the doors will not close unless I turn off the key. If I bypass the relays (back to original wire routing) everything works the way it should.

I'm also running a powermaster 100amp (not 1 wire) alternator. I have a jumper wire across the end terminals of the old regulator connector and thought I was getting back voltage there so I added a diode to the jumper. That didn't help.

I also tried putting a diode on the positive side of the headlight trigger circuit at the relay terminal but that didn't help either.

I like the added brightness of the headlights with the relays in place and don't want to go back to the original wiring method if I can avoid it. I just don't understand why the headlight relays are staying energized.

Any ideas?

Thanks guys,
Jason

[OHCbird]

Check your door motor switch & limiters; it sounds like it's keeping power to the relay 'on' circuit.

Either that, or you wired it that way. Normally your inner & outer limit switches cut off power on each end of the cycle.

[67RS]

I don't think thats it because if I bypass the headlight relays the doors open and close like they should.

I agree that the headlight-on circuit is staying energized and I think that the headlights shutting off triggers the doors to close but I'm not sure why the headlight-on circuit is staying energized.

All of the relays are grounded at the same bolt, is that bad? I wouldn't think so. Should I add a diode to the ground side of the on circuit?

All of the switches, motors and relays are new and I'm pretty sure they are working properly.

[eldogg]

You might wanna try grounding 87a on the relays so the wires will rest at ground instead of just an open circuit.
just a thought,
Eldogg
Queen City Speed

[67RS]

Well, I finally figured it out. I sat down and stared at the wiring diagram for about an hour and figured out exactly what was going on.

It turns out that the circuit that controls the door closing (relay2 and relay3), grounds through the headlights. The headlights have less resistance than relay 1 and so there isn't enough voltage through relay 1 (the door opening relay) to energize it.

David Pozzi's site has the wiring diagram if you really care to follow.

When the headlight relays were added they were effectively in parallel with relay 1 and have similar resistance. Now when the headlights are shut off the door closing circuit grounds through relay 1 and the headlight relay. What ends up happening is that the headlights stay on and all 3 of the door control relays are energized and the power to the door motors is run straight to ground and blows the fuse.

So far I haven't come up with an alternative and I think the headlight relays are going to have to go if I want the doors to work right.

The bottom line is: If you have a 67' RS and want the headlight doors to work properly you can't have relays running your headlights.

[paul67]

Why can you not ground the door closing circuit to the subframe or body and bypass the relays ?
paul67

[67RS]

Its hard to explain without walking you through the wiring diagram but I'll give it a shot.

Basically the door closing relays would always be energized if you were to ground that side of the circuit. When the lights are on that side of the circuit is powered through the headlight switch. The other side of the circuit is powered by the ignition switch. That makes the potential on both sides of the door closing relays (R2 and R3) the same. With the potential the same no voltage flows and the relays are not energized. When the headlight switch is turned off, power flows from the ignition switch, through R2 and R3 (energizing them), through the high beam/low beam switch and out to the headlights. R1 is in parallel with the high beam/low beam switch and the headlights. The reason it doesn't become energized is because the resistance through the switch and headlights is less than through the relay (R1) so not enough power flows through it to energize it. When I added the relays for the headlights they were put in place of the headlights in the circuit. Now R1 and the headlight relay are in parallel and the power splits between the two and both become energized. Remember that R2 and R3 are also energized. If you follow the wiring diagram you will see that if all 3 of the door relays are energized the high side of the relays runs directly to ground and blows the fuse (or circuit breaker as the case may be). Remember also that the headlight switch is turned off but the headlight relay is energized, so my headlights are on even though the headlight switch is off.

I think I've figured out a way to keep the headlight relays but I havent tried it yet. If it works I'll post the wiring diagram.