GT Headlights Won't Turn On

[tnopelgt]

Help,
I tried to turn on my headlights the other day and they are not working. The lights roll over and the white light on the dash comes on, but no power to the lights. I checked the wires with a tester and the only power I am getting is from the red wire coming into the relay. i also made a new grounding spot for the wires in the front because the other had rust and was in a bad location. If any one knows why i am not getting power it would be greatly appreciated. Thanks

[jimsky]

GT headlights, a common problem. First question is, have they been rewired yet? This is not a suggestion, it's really a "must". The rubber wire originally used rots out over time. Virtually all stock GT"s have shot headlight wiring. To check take off a headlight cover and take a peek where the 3 prong connector plugs into the headlight bulb. If the wire is dry and crumbly, time to re-wired your headlight. There is a headlight article in the Tech download section here at mentions re-wiring tips, and you will find various other articles and threads if you search. The original headlight wiring had no fuse protection, unfixed this is a real fire hazzard. Fixing the headlight wiring was the first thing I did on my GT. You will sleep better at night knowing this has been done. Doing this is the start of troubleshooting any electrical headlight problem. Good luck!

[GabeGt73]

Hi, I'm also a newbie, but I was reading the homepage, and found in the links an awesome article for your problem with headlights. You should be able to find it, download and print it.

[GabeGt73]

GT Headlights
Description: GT headlight article in MS Word format.
Version: 1.0 Filesize: 0 bytes
Added on: 30-Mar-2002 Downloads: 417
HomePage | Rate Resource | Report Broken Link | Details

[Gary]

Heres a Link to an article in the Encyclopedia section on this site about rewiring the GT's headlights.

[kwilford]

Trouble-shooting over the Internet, my favourite thing!

First, are the buckets completely "open"? Are they "latched" open, or can you rotate either of them by hand once they are open? You say the white light comes on as you roll the lights. Does it go off at either end, especially the open position? This light should only be on while the headlamp buckets are "in-between", and lights up as as an idicator that one or both of the buckets are not fully open (or not fully closed). If so, then the bucket gears are not completely rotated, and the latch may not be fully engaged. They have to COMPLETELY engaged in order to trip the last internal micro-switch, located in the left bucket. This micro-switch in turn energizes a relay, which is under the dash. If your problem is mechanical, go to the download section and read Wayne Torman's article on repairing those darn headlights at

http://www.opelgt.com/modules.php?s=...op=getit&lid=1

Which takes us to the electrical system. Do you have an electrical schematic (factory service manual)? It makes stuff like this SO much easier. If not, go to the "Tech Info" section of the Opel Association Of North America site and download a wiring diagram:

http://clubs.hemmings.com/frameset.cfm?club=oana

or directly to:

http://clubs.hemmings.com/clubsites/oana/tech.html

The headlight wiring is a good place to look, but there can be other problems.

If the white light comes on with the buckets "in-between", then the "on/off" relay "should" be OK, since the indicator light is supplied with power from the output of the "on/off" relay. So it might be the wiring, or it could be the dimmer relay. Do the high beams work? Check to see if you have power to the dimmer relay (thick white w/ yellow stripe wire, connected to terminal ""56" on the right-most silver box up under the dash, comes from terminal "87" on the "on/off relay). You MUST have a test light if you are going to trouble shoot electrical, or a voltmeter! If you have power to the dimmer relay, but not from it (terminal "56a" for high beam, "56b" for low beam), then the dimmer relay contacts may be burned, or the mechanism stuck in between. Often you can remove the relay, carefully open it, and clean the contacts and maybe un-jam the relay. Or find a new/used dimmer relay.

But if is not the dimmer, another common problem is the headlamp "on/off" relay (versus the headlamp "dimmer" relay, which is right beside it), which is the left-most silver box down under the dash. Although it has probably been eliminated in this case by the fact the white light works. It has a thick red wire (attached to a terminal marked "30/51") which is the power input to the relay. Use your test light to see if you have power to here. Then, when your headlights are open, check that you have power to the "output" terminal, (one of four which are marked "87") and has two thick wires connected, white with a yellow stripe (one connects to the dimmer relay, to it's terminal "56", and ultimately to the headlights). If not, see if the energizer coil has power, by checking terminal "85" (it has a thick yellow w/ black stripe wire). If not, then either the micro-switch in the headlamp bucket has failed, is "open", or the wiring has a break in it.

I hope this helps, and let us know some of the answers I posed above it you haven't fixed it.

[kwilford]

We just had this issue on the classicopels site, and here is my post and what the owner found in the end. And after I looked more closely at the wiring schematic, I realized that the white light will come on when the relay isn't energized due to a faulty relay microswitch, and the buckets are competely open, with the ignition on. Oops, I gave away the answer! But I just LOVE happy endings! Here is the tread:

--- In classicopels@yahoogroups.com, "Joe Van Wagnen wrote:

I've finished the rewiring and put everything back together. When I turn on the headlights the white dash light is on but the
headlights don't light up.... do I have a microswitch out of adjustment??? How can i tell which retractor mechinism to take out??
I'm guessing it is the headlight indicator microswitch but which
one??

Any help would be apreciated

Thanks
Joe Van Wagnen




Date: Sat Jan 18, 2003 1:57 am
Subject: Re: Headlight troubleshooting


I assume that you are confortable with wiring, if you took on the
task of re-wiring the headlamps, and that you have a wiring diagram
and test light. For those who are considering this very necessary
task, you REALLY need a wiring diagram to help troubleshoot it if
you have problems. If you don't have a factory service manual
(which you NEED!), then surf to the Opel Association of North
America (OANA) site at:

http://www.opel-na.com/

and go to the "Tech Info" page, where you will find wiring diagrams
for your GT; download one, & make sure you pick the right year.
Early GT's, before mid 1970, had somewhat different wiring than
later models. I will assume that you have a later (most common)
model.

Since you have just rewired, I would start by looking for either a
bad connection in the new wiring, or perhaps a transposed pair (or
more) of wires. Start by tracing the new wiring with the wiring
diagram. Painful, but essential, if you are planning on avoiding
turning your new wiring job into a melted mess. Since you have both
a white light and non-functioning headlights, it is probably the
main headlamp relay or the relay microswitch. The white light will
come on when the headlamps are open, the ignition is "on", but the
relay fails to close. Then the unpowered side of the relay acts
like a "ground" for the white light. Here are a few things to
check.

Make sure your ignition is on. If your headlights are fully opened,
and are "latched" (BOTH sides), the relay microswitch (in the left
bucket assembly) should be supplying power from the switched side of
the fuse box (via a 12 guage black wire) to the #85 terminal (12
guage yellow w/ black stripe) on the headlamp relay.
This "energizes" the relay, closing an internal contact, and
transmits power to the headlight dimmer switch (the other silver
relay next to it). Use a test light light to confirm this. If you
don't have a test light, stop now, and go get one. Also check that
the power going to the dimmer relay is leaving it, since it supplies
power to the headlights, via terminal 56a to the high beams, and 56b
to the low beams.

If there is power to the #85 terminal, the relay microswitch is
working. Make sure the relay itself is supplied; it should have
power at the #30/51 terminal (12 guage red wire) directly from the
hot side of the fuse box (which is the wire where you should install
a fuse or breaker, 30 amp, to keep from melting down the ENTIRE car
should you short a headlamp wire). If you have power to both of
these terminals, check to see if the relay is actually functioning,
by looking for power coming OFF at the # 87 terminals (several
wires, all 12 guage; white w/ yellow stripe, gray w/ green stripe,
gray w/ red stripe, gray w/ black stripe, yellow w/ black stripe).

If you have power to all of these terminals, your relay is
functioning, and you have a bad connection or transposed wire in
your new harness. If you have power to the first two termnals I
mentioned, but not FROM the relay (the #87 terminal), the relay
isn't closing the internal contacts. This can sometimes be repaired
by disconnecting it (MARK THE WIRE POSITIONS!) and GENTLY opening
the case. Then clean the contacts, and make sure it "trips" when
power is supplied to the #85 terminal (the relay has to be grounded,
at terminal #86).

As for the white indicator light, it is powered when one microswitch
is tripped, but not the other, which usually indicates the buckets
are "in-between" open and closed. If the relay has checked out, and
the headlights still don't work, you may have a bad connection in
the new wiring (or two burned out bulbs? Not likely, but possible).

HTH, and good luck.

Keith Wilford
'71 GT



From: "Joe Van Wagnen"
Date: Sun Jan 19, 2003 10:21 am
Subject: Headlight troubleshooting

Thank you:

Otto
Lindsay
Keith
Gordon

For your help.... it turned out to be a dirty microswitch feeding
the headlight relay.... works great now!!!

I ended up replacing all three wires to each headlight, all the
front grounds and a new wire to the right turnsignal... no more
shorts or bad grounds

now on to the new front bumper mount, new bumperette
then drop the rearend for restoration

Joe Van Wagnen
71 2.4l GT

[NEWGT71]

I am almost ready to have my 72' GT safetied. However
I still have a couple small problems, and not being so
good with electrical problems I was hoping someone could help. The high beam switch in the steering column is busted. I hope to
get around this by using a toggle switch. Which wires would I need to connect to get the hight beams working? Right now I just have low beams.

Any help would be appreciated.
RP

[kwilford]

The High Beam Dimmer Relay is "actuated" by the stalk switch, that grounds the wire for just the moment that you pull the stalk back. This grounding completes a solenoid circuit in the relay, and the internal contacts trip from one position to the other, and back the next time the relay is grounded. It is the green wire on the relay (Terminal "S") that in turn connects to the stalk switch, and the other side of the stalk switch is grounded. Is the the stalk actually broken, or is it possible that:

1) The stalk switch contacts are dirty? Tricky to fix but I have heard it can be done.
2) The ground wire to the stalk switch is not grounded? Make sure the column is properly grounded.
3) The dimmer relay itself isn't working? Easy to check; just apply a ground to the "S" terminal when the headlights and ignition are on. No dimmer trip, bad relay. They can be opened up (carefully!) and often it is just the trip mechanism is gummed up, or sometimes the contacts are dirty or welded closed in one position.

If the stalk is broken or the stalk switch is unrepairable but the relay is funtional, you just need a "push-closed" (normally open) switch with one side grounded and the other connected to the "S" terminal. If you continually ground the relay solenoid with a toggle switch, it will burn out. Bye bye dimmer relay.

HTH

[NEWGT71]

Thanks for the help Keith!
When I apply ground to the "S" terminal the relay flips. However
I only get lights in one of the 2 positions. When the headlights are on I have power to the yellow wire on the 56b terminal. When the relay flips there is power to the white wire with yellow stripe on the "56" and the "+" terminal. At this point there are no
lights. This white wire with yellow stripe then connects into the relay beside the headlight relay. What happens from this point on?

I believe the headlight wiring to be okay, cause I rewired from inside engine compartment on.


Any suggestions would be appreciated.
Thanks
rp

[kwilford]

Low beams are powered by the dimmer relay 56b terminal (should be Yellow wire) and the high beams by 56a (White wire, with the second wire of the same colour going to the high beam indicator on the dash). The white/yellow stripe wire should come FROM the headlamp relay (which is activated by the microswitches in the headlight mechanisms) and SUPPLIES power to the dimmer relay to terminal 56 (and to the "+" terminal via a short jumper, which in turn is the power to the dimmer relay solenoid). Sounds like you have some wires transposed. If you don't have a wiring schematic, surf to the OANA site at

http://clubs.hemmings.com/frameset.cfm?club=oana

and then to the Tech Info section and get a diagram. You want the '72 GT version.

HTH

[NEWGT71]

I think my problem is with the headlamp relay. On the downloaded wiring diagram I can't see which wires are supposed to be on which terminal. Can anyone give me a run down of the correct wire and terminal combinations?
Thanks

[odieopel]

The diagram is hard to read, the terminal numbers and wire colors are as follows-
upper left hand (30/51) red
upper right hand (85) yellow w/black tracer
middle right hand (86) brown
lower terminals all marked (87) left to right
1-grey w/green tracer
2-grey w/red tracer
3-grey w/black tracer
4-white w/yellow tracer
Hope this helps....

[benncojr]

I had the same problum a couple years back. I was able to trace it to a micro swich behind the headlights. The only way to gain acces to it was to take the driver side frount wheel off and there is a acces door in the wheel well at the frount. (if there is rustproffing you will need to scrape it off).

From there you will be able to see how it works. Have a person operate the headlights leaver while you watch the swich work. In may case the pickups were not hitting the swich, a little bend of the pickups fixed it.

I hope this helps

[rangerrick]

Well I'm glad to have found this thread as I get the white indicator light on the panel but have no driving lights with the buckets in the up position! I cycled the buckets several tims hoping to finally get it to make the micro switch, found out the headlamp handle can bend on you as well ( thought this is BS the handle lever steel should be harder) I drove home following another car 23 miles up a two lane hwy. with my parking lights only!!! I've yet to re-wire the headlights since I got the car 4 months ago (been too busy replacing brakes, engine mounts, exhaust, carb, shocks, fuel pump, oil press. transmitter and vacuum modulator on trans.) ect....Hell I still don't e even have a radio that works in it yet!!! Guess that shows my age, fixing mechanical things instead installing tunes first as a teen!!!

So now I'm forced to get into the headlight wiring and rigging their travel and maybe upgrade the alternator to at least a 50 AMP. Which with having the GM air/cond. compressor (almost as big as the engine) over the alternator I'm not sure I can get the alternator out without breaking the sealed compressor??? Any how love the roll over lights, however seem a bit complicated and the cable system sucks!!! I was wondering if anyone has thought of hooking up a motor to drive the lights instead of a cable??? Hell the system already is complicated, why not add a motor and gearbox relay and switch to electrically drive the buckets at the same time of re-wiring and rigging!!! Now would also be a good time to turn the turn signals into driving lights in case I have to use them to drive home in the dark some day!!!
One thing I've learned as Namba has told me (Frustration) I find myself whining a lot before I've taken on some of these Opel projects and rigging og electric switches and relays seems too much like working on aircraft...

[soybean]

rangerrick, Try this link on linear actuaters, it may be of some help. http://www.opelgt.com/forums/showthr...near+actuators
HTH. Jarrell

[namba209 (R.I.P.)]

Rick, first off, you can move the GM AC compressor without disconnecting the hoses to get to the alternator, if you think you need to. I've done it many times, just disconnect it from the mounting plates, but do not disconnect the hoses if the system is functional. As for the headlights, the buckets need the mass rotation impetus to lock in place. It would hard for a mechanical actuator to lock them in place. The same holds true to unlock them. The alternator of choice for an upgrade is the GM 7127, one-wire setup, there are ample directions on how to install one, just do a search and you'll find it. The big thing on the headlights is where the wires go through the rotating mechanism. That's where problems usually occur. Check out the technical section of this forum, I believe there is a good article on how remove and re-install the buckets. If not it is on the Yahoo Classic Opel site. BTW, are you having fun yet? HTH.