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Discussion Starter · #1 ·
Hello, i have a questions for you about headlights:

When I pull the headlight lever, should only the upper front headlights be turned on?
do the rear lights have to turn on?
Shouldn't the dashboard instrument lights turn on?

Thank you, and sorry for my english.
 

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Hello, i have a questions for you about headlights:

When I pull the headlight lever, should only the upper front headlights be turned on?
do the rear lights have to turn on?
Shouldn't the dashboard instrument lights turn on?

Thank you, and sorry for my english.
In a Opel GT with stock (original) wiring, flipping the headlight lever fully should also turn on the headlights, taillights, side marker lights and license plate light.
Your dash lights should also illuminate, provided the rheostat switch (dimmer toggle switch directly to the left of the cigar lighter ) is not set to zero (all the way up)
431197
 

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Discussion Starter · #3 ·
Thanks for the reply.
If I press the button for the headlights on the dashboard (the first) what should turn on?
Everything except the upper headlights?
I believed that the lever operated only the upper headlights and the button on the dashboard the rest.

In a Opel GT with stock (original) wiring, flipping the headlight lever fully should also turn on the headlights, taillights, side marker lights and license plate light.
Your dash lights should also illuminate, provided the rheostat switch (dimmer toggle switch directly to the left of the cigar lighter ) is not set to zero (all the way up)
 

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Thanks for the reply.
If I press the button for the headlights on the dashboard (the first) what should turn on?
Everything except the upper headlights?
I believed that the lever operated only the upper headlights and the button on the dashboard the rest.
Yes, the first button will turn on the tail lights and side markers and dash lights (provided the dimmer is not set to off) I often used these when I wanted some additional visibility on the road, but didn't need the headlights. Remember that these lights will stay on, even when the car is not running. Easy to drain the battery if you should forget to turn them off.
 

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Just Some Dude in Jersey
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I am a big proponent of rewiring the headlights so that the Parking light switch turns on everything. You remove the microswitch wire from the headlight relay and run a jumper from any of the parking light circuits to that terminal on the relay. Flick the parking light switch and all the lights come on. The jumper carries almost no power, it only activates the coil on the relay, the relay contacts carry all the big power, so no worries about blowing fuses. You should then cut the microswitch wire off at the fuse box and tape it off, it is now useless and has live always on power in it. With this mod you can leave your headlights up if you want to all the time. It is no longer necessary to have good working headlight rotators and a smooth working cable just to turn on your headlights. I have been doing this mod to all my GT's for 35 years and it is SOOOO much better. I didn't invent it, it was already done on a car I had in the 80's/90's(Ole Yeller) by the head mechanic at an Opel/Buick dealership. Accident damage and poorly repaired headlight openings made the headlights impossible to flip without hitting the body. The next car I had also had the same problem(Red Baron), so I did the mod to that car also. My present car had the headlights modded away in favor of small tunnel headlight, so the light functions are all on separate switches. I just got a new car and the headlights work perfectly, smoothly, and easily, but the cable appears to be rusted. Do I replace the expensive cable so that I have to use 40lbs of 50 year old mechanical junk to flip my headlights, just so that I can turn my headlights on. No friggin' way! In 10 minutes I could run the jumper wire and tape off the microswitch wire and I can turn my headlights on at the flick of a switch. I prefer to have my headlights up all the time anyway. If I want to show off the car's "trick" of flipping headlights, I could install servos or linear actuators and make them flip back and forth with a switch.

FYI: Our headlights are unfused. You MUST install inline fuses to the high and low beam power wires.

SUPER IMPORTANT FYI: Opel flucked up and used vinyl wrapped headlight wires from the radiator, where the hi/lo power wire splits in two to feed the right/left headlights. This vinyl wrap dried out and turned to dust on all GT's as far back as the 80's. This can cause a dead battery short to ground and many, many, GT's have burned to the ground or had the entire fuse box and wiring to melt and short out. We tell all new GTers that this is the very FIRST thing you must do to all GT's before you dare to flip the headlights. The wires run through a tight tube in the pivot mechanism. Of course, flipping the headlights repeatedly is the first thing that everyone wants to do when they get a GT.

MAKE SURE THAT THE HEADLIGHT WIRES HAVE BEEN REPLACED before you do any more headlight flipping!

:)
 

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Opel Key Master
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SUPER IMPORTANT FYI: Opel flucked up and used vinyl wrapped headlight wires from the radiator, where the hi/lo power wire splits in two to feed the right/left headlights. This vinyl wrap dried out and turned to dust on all GT's as far back as the 80's.

:)
The vinyl wire is the good wire, Opel used Rubber jacketed wire from the booster to the headlights, the rubber dry rotted and caused them to short out. The vinyl wire is all the other wire in the system. The vinyl wrap used on later years did accelerate the rubber wires to deteriorate where early used a PVC gray sleeving of sorts that better protected the wire
 

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Super Moderator
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My understanding is Opel used better grade wiring than Brissonneau and Lotz, who built the GT bodies in France.
 

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Discussion Starter · #8 ·
Thank you all. I ask this because I am redoing the electrical system but I am having some problems with the headlights. When I pull the lever everything turns on. The small headlights below are high beam and not low beam. Another strange case, when I press the switch on the dashboard to turn on the headlights (the first one), the fuel gauge peaks, and the lights in the instrument panel stop working. The same thing happens if I press the wiper button on the dashboard.
 

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Pedal Smasher
1973 Opel GT
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It's worth noting that our Italian member has a Euro-spec GT and not a US-spec GT. So, there will be a headlight switch on the dash that US-spec GT's don't have. I can't remember all the differences in how the lights work for Euro-spec GT's but I do know about the additional switch on the dash. Unless this is an Italian export GT, which I think was more like a US-spec GT???
 

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1970 Opel Gt - Purchased July 1972 - Chartreuse - restored - 3000 miles as of 02-16, 2021 -
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I am in the process of working out some kinks in my head light wiring as well and have spent several hours with the front seat out laying on my back trying to figure it out. I replaced the front lighting wiring harness back around 2000 and I don't recall everything evolved except I ended up with more wires on the new harness that the original harness had, most likely a newer version of my harness, perhaps a 1971, the wires were not labeled. Prior to the rewiring when I flipped the lights everything came on light related, this is a 70 model. After the change of wiring I now have to use the dash switch to turn on the lights which in the past provided no function. Additionally below that larger main dash light switch is a small button/switch with the light symbol on it that I am pretty sure never did anything and still does nothing, but I guess that would be for the parking lights. I have been looking at the OPEL GT Coupe wiring diagram for 1970 for the last couple of days and I see a part labeled revolution relay "1970 0nly". The diagram that I am looking appears to show - A HDLT Relay SW and A HDLT IND Lamp SW and a Beam Selector Relay and a Head Light Relay still trying to figure that all out as best I can tell my GT only has two relays with a total of 12 connections, this diagram is showing 5 relays having to do with the head lights. I know there are those out there that understand all of this, I don't. However suggest you continue to do as I am doing and reading all of the related comments. The solution may already be there but I have also noticed that I always learn something unrelated that helps me. Good luck.
 

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WRT: "...rewiring the headlights so that the Parking light switch turns on everything."
What I thought was a good idea was to use the parking switch to turn on a daytime running light function:

And, if you use all LED bulbs in that circuit, it won't draw much current --- just in case you forget to turn it off.
 
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