head lights out !!

[Dale .D]

Going to work at 5 am, dark country road. All head lights shut down. Almost SH! myself. Got back home on my emergency flashers. If I blinked just right I could barely see. All other lights are fine including the dash thingy saying my lights are on. The whole light system was rebuilt a couple of years ago & have been perfect. The high beam switch doesn't click now on the steering wheel!! No high or low beam. Hope the problem isn't in the column. Been reading about fusible links off the starter & starter relays. Checked out visible wiring & grounds & seem fine. What should I do next? I like pictures. Also my low beams have alway been super low. Not sure if thats a factor. Which one is the relay switch behind where the fuses are? Thanks for all advise.

[rsefczek]

had exactly the same problem and wound up leaving the car in a parking lot while i got a ride home. finally tracked it down to the microswitch in the rotating mechanism which crapped out for whatever reason. i was able to jump across the headlight relay to bypass the microswitch so i got lights back. try bypassing the microswitch and see if the lights come on. also, check the grounds! very common problem. basically you need to trace along the headlight circuit and find out where the interruption is.

bob

[Dale .D]

had exactly the same problem and wound uleaving the car in a parking lot while i got a ride home. finally tracked it down to the microswitch in the rotating mechanism which crapped out for whatever reason. i was able to jump across the headlight relay to bypass the microswitch so i got lights back. try bypassing the microswitch and see if the lights come on. also, check the grounds! very common problem. basically you need to trace along the headlight circuit and find out where the interruption is.

bob

Where is this micro switch?

[sawdust]

Where is this micro switch?

rotator - Opel Photo Gallery

you have two rotators

[rsefczek]

the microswitch (es) are located on the back of the rotator mechanism and are a bugger to get at, that's why bypassing them to see if they are the problem is better than just going after them

bob

[wrench459]

Check the ground over by the brake booster. I think thats the grounding
point for both headlamps.

[Dale .D]

rotator - Opel Photo Gallery

you have two rotators

Great picture. I see now. Is the fact that the clicker not working after the lights went out point to the problem? Don't want to start taking things apart until I know the problem is probably there. Is the main relay switch one of the prug-in units by the fuses?

[Gordy]

If the tail lights and dash lights come on when you flip the lights then the micro switch is doing it's thing and thus the tail lights etc work. If that switch were bad there would be no lights at all.
If nothing happens the micro switch is bad.
If the tail lights and side markers DO come on, then the relays down in the fuse block are bad and they aren't making the headlights come on. Change the relays in the fuse block.

[Dale .D]

If the tail lights and dash lights come on when you flip the lights then the micro switch is doing it's thing and thus the tail lights etc work. If that switch were bad there would be no lights at all.
If nothing happens the micro switch is bad.
If the tail lights and side markers DO come on, then the relays down in the fuse block are bad and they aren't making the headlights come on. Change the relays in the fuse block.

Now we are making some headway. Not really electrically inclined so really glad for the help. All lights work as normal except the headlights. Is there a main relay switch & a high & low relay switch? Both high & low beam disappeared? As well the clicking on the column arm went at the same time doesn't work as well. That must point to something. Doing this process of elimination is great with you folks in the know. Thanks! So far it seems that we have eliminated the micro switch. Are there any pictures out there showing the location of the main or hi & low relay switches?

[sawdust]

Are there any pictures out there showing the location of the main or hi & low relay switches?

fuse panel

Fuse Panel_2.jpg

[Gordy]

Because the relays are shot there will be no "click" as you pull back on the turn signal indicator lever. I had my dim relay go out once and by holding the lever back it kept the high beams engaged so at least I could drive home.

[Anonymous D]

Headlight circuit diagnosis information available at link.

http://www.opelclub.com/GTHeadlightsAugust2004.pdf

[wrench459]

Step 5 just how do you check the ground?
And you could have power at "A" and "B" with very little current flow.

[Dale .D]

Headlight circuit diagnosis information available at link.

http://www.opelclub.com/GTHeadlightsAugust2004.pdf

Good article.Are the 2 units there the high & low beam relay circuits?

[Dale .D]

Headlight circuit diagnosis information available at link.

http://www.opelclub.com/GTHeadlightsAugust2004.pdf

So at this point would it be prudent to replace these 2 relays from OGTS & see if it does the trick?

[kwilford]

So at this point would it be prudent to replace these 2 relays from OGTS & see if it does the trick?

Dale, to start replacing parts to see if they are the problem is a bit problematic. And expensive. My advice is to systematically trouble shoot the headlight circuitry. It's not very difficult, although some folks talk as if its rocket science. To start, make sure you have the Factory Service Manual headlight schematic at hand. I like the circuit-specific schematic, such as Figure 120-102 in the 1971 and 1972 FSM's rather than the big colour all-circuit schematic. Start by following the logic of the headlights in the schematic so you see how they work. Then do some simple tests. The description in the OMC article is pretty good, so also refer to that while you check:

1) Is there power to terminals 30/51? That is the main source of power for all the headlights, right off the main fuse box bus (NO FUSE!). If you have parking and dash lights, you must have power to 30/51, so move on.

2) headlights open, ignition on: Is there power to terminals 85 (which is sourced from the ignition, via the micro-switch) on the headlamp relay?

3) Again, that probably isn't the problem, since you have parking and dash lights, so I would expect that the headlamp relay IS working, and the problem is "downstream" and confined to the headlight circuit. For the sake of others doing trouble shooting, if no power to 85, then work your way back through the schematic, by checking if the headlamp relay switch (the famous micro-switch) is getting power (comes from a black wire on the fuse box, refer to the schematic). If so, and no power at the #85 terminal, then the micro-switch isn't working. This is NOT as common as folks seem to think, at least by the number of GT's that have had the micro-switches bypassed by some abomination of PO wiring. Another way to check is to simply use a wire lead and PUT power directly to #85. If the headlights come on (or you now get power to the relay output, terminals #87), then either the micro-switch is malfunctioning, or there is a problem with the wiring.

4) if the relay IS getting power to #85, is there power at the #87 terminals? If not, the relay is malfunctioning. Either try repairing it (another thread talks about that somewhere here, I've done it, not very difficult) or buy a replacement. If yes, then follow the power to the next location, which is the dimmer relay.

5) ignition on, headlights open, power at #87 on the headlight relay: Is there power to #56 on the dimmer relay? Bloody well better be, as the wire is only about two inches long!! But check if there is power at either #56a (high beam) or 56b (low beam). Should be at one or the other. If neither, then the dimmer relay is malfunctioning (either repair or replace).

6) You're on the home stretch. If you have power to the dimmer output terminals but still no headlights, you have a problem with either the wiring to the headlights (and GT's are more than famous for that) or a bad ground to the headlights (also common, check the multi-wire ground as they attach to the body with a screw on the driver's side inner fender just ahead of the radiator brace) or maybe even two burned out headlights (not bloody likely if you have NEITHER low nor high beams).

HTH

[Dale .D]

Dale, to start replacing parts to see if they are the problem is a bit problematic. And expensive. My advice is to systematically trouble shoot the headlight circuitry. It's not very difficult, although some folks talk as if its rocket science. To start, make sure you have the Factory Service Manual headlight schematic at hand. I like the circuit-specific schematic, such as Figure 120-102 in the 1971 and 1972 FSM's rather than the big colour all-circuit schematic. Start by following the logic of the headlights in the schematic so you see how they work. Then do some simple tests. The description in the OMC article is pretty good, so also refer to that while you check:

1) Is there power to terminals 30/51? That is the main source of power for all the headlights, right off the main fuse box bus (NO FUSE!). If you have parking and dash lights, you must have power to 30/51, so move on.

2) headlights open, ignition on: Is there power to terminals 85 (which is sourced from the ignition, via the micro-switch) on the headlamp relay?

3) Again, that probably isn't the problem, since you have parking and dash lights, so I would expect that the headlamp relay IS working, and the problem is "downstream" and confined to the headlight circuit. For the sake of others doing trouble shooting, if no power to 85, then work your way back through the schematic, by checking if the headlamp relay switch (the famous micro-switch) is getting power (comes from a black wire on the fuse box, refer to the schematic). If so, and no power at the #85 terminal, then the micro-switch isn't working. This is NOT as common as folks seem to think, at least by the number of GT's that have had the micro-switches bypassed by some abomination of PO wiring. Another way to check is to simply use a wire lead and PUT power directly to #85. If the headlights come on (or you now get power to the relay output, terminals #87), then either the micro-switch is malfunctioning, or there is a problem with the wiring.

4) if the relay IS getting power to #85, is there power at the #87 terminals? If not, the relay is malfunctioning. Either try repairing it (another thread talks about that somewhere here, I've done it, not very difficult) or buy a replacement. If yes, then follow the power to the next location, which is the dimmer relay.

5) ignition on, headlights open, power at #87 on the headlight relay: Is there power to #56 on the dimmer relay? Bloody well better be, as the wire is only about two inches long!! But check if there is power at either #56a (high beam) or 56b (low beam). Should be at one or the other. If neither, then the dimmer relay is malfunctioning (either repair or replace).

6) You're on the home stretch. If you have power to the dimmer output terminals but still no headlights, you have a problem with either the wiring to the headlights (and GT's are more than famous for that) or a bad ground to the headlights (also common, check the multi-wire ground as they attach to the body with a screw on the driver's side inner fender just ahead of the radiator brace) or maybe even two burned out headlights (not bloody likely if you have NEITHER low nor high beams).

HTH

Great info as always.I'll give it a try.Thanks

[Dale .D]

Well there's power at # 85 but not at # 87.So it looks like that Relay is shot.I'll order that relay & for the heck of it take it apart & See if I can see the problem. Now for a cruise on the new paved rd between Lake Cowichan & Port renfrew.Cheers & Thanks a bunch.If your ever on the Island Keith!

[kwilford]

Well there's power at # 85 but not at # 87.So it looks like that Relay is shot.I'll order that relay & for the heck of it take it apart & See if I can see the problem. Now for a cruise on the new paved rd between Lake Cowichan & Port renfrew.Cheers & Thanks a bunch.If your ever on the Island Keith!

Hmm, are you SURE that there is power to #85 (which means that the headlight micro-switch relay is working), AND power to #30/51 (the main headlamp power feed from the fusebox bus) and yet no power at #87 (which should come on when the relay is "energized")?
And you have parking and dash lights when you are checking?
Do you have the parking light rocker switch on then, or off?
What happens if you jumper a lead from #30/51 over to #87? The headlights should come, as that bypasses the relay.

[Dale .D]

Hmm, are you SURE that there is power to #85 (which means that the headlight micro-switch relay is working), AND power to #30/51 (the main headlamp power feed from the fusebox bus) and yet no power at #87 (which should come on when the relay is "energized")?
And you have parking and dash lights when you are checking?
Do you have the parking light rocker switch on then, or off?
What happens if you jumper a lead from #30/51 over to #87? The headlights should come, as that bypasses the relay.

Headlights were up,Ignition on but the parking light rocker was not on.I'll do it again & see what happens with the rocker on.