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Opeler
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Discussion Starter · #1 ·
hopefully this is an easy one for this list. where is the headlamp relay switch? is that the microswitch next to the driver's headlight?
 

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If you're talking a 71 or later GT, the headlight relay microswitch is in the driver's side headlight bucket on the back side of the rotating mechanism. To see if it is working, rotate the headlights to the open position and check for voltage on the Yellow/Black wire going to the headlight relay on the firewall side of the fuse panel. HTH.
 

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Opeler
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159 Posts
Discussion Starter · #3 ·
thanks, that what i thought. i'm in the middle of a rewire (ez-wiring) and i have to run one to the relay switch but wanted to make sure i had the right one. jeez there are a lot of relays for the headlamps
 

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Actually there's only two relays for the headlights, one to turn them on and off, and one to switch between hi-lo beams. The other relays behind the fuse panel are for the ignition switch buzzer and seat belt buzzer. The two big ones are for the headlights, the two small ones are the buzzers.
 

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Opeler
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Discussion Starter · #5 ·
yeah but my wiring diagram also shows a headlamp relay switch which is what i think the microswitches are in the headlight bucket
 

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Member
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You are correct #7 in the shop manual page 120-42 , welcome to the opel world of wiring diagrams :eek: next page for automatic trans. calls it something else.. HTH
Guyopel
 

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O.K., maybe a bit of clarification is needed here. First off, I'm using JJ Wheatley's DESTEC wiring schematic, which is a must for any GT owner, IMHO. Secondly the microswitch in the headlight bucket is used to energize or activate the headlight relay, basically an electromagnet that makes an electrical connection to route 12 volts to the headlights, clearance lites, parking lites and instrument lites. Depending on which year GT you have, there will be microswitches in only one bucket or both, but only one in the driver's side bucket operates the headlight relay, the other one or two are for the headlite indicator lite between the speedo and tach. That lite indicates only if the buckets are in transition, that is, not locked open or closed. HTH.
 

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Pathologic Opeler
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headlights were out

namba209 said:
O.K., maybe a bit of clarification is needed here. First off, I'm using JJ Wheatley's DESTEC wiring schematic, which is a must for any GT owner, IMHO. Secondly the microswitch in the headlight bucket is used to energize or activate the headlight relay, basically an electromagnet that makes an electrical connection to route 12 volts to the headlights, clearance lites, parking lites and instrument lites. Depending on which year GT you have, there will be microswitches in only one bucket or both, but only one in the driver's side bucket operates the headlight relay, the other one or two are for the headlite indicator lite between the speedo and tach. That lite indicates only if the buckets are in transition, that is, not locked open or closed. HTH.
my headlights go out for no good reason from time to time...for a min or two..then come back on..
when the headlights went out tonight, i had no dash lights either. all the right 3 fuses were dead too. the left 4 fuses and center nuts were hot.
the relays on the fusebox were all dead,except for the red wire. the white striped,yellow striped, and grey striped wires were all dead at the fusebox.

if ..I turned on my parking lights then the right 3 fuses were now hot along with
the grey striped wires at the fusebox, headlights remained off.

i rotate the headlights a few times or shake the car and the lights come on...

Question 1: Sounds like a bad headlight microswitch at the bucket?
 

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O.K. Dean, using JJ's schematic, it looks like one of two things, a stuck microswitch as you suggested. Easy to check out, look for 12V on the yellow/black wire on the relay with the headlights open/on. Also check for 12 volts on the large black wire on fuse #6 (2nd from the left on the bus bar side), it should be hot with the ignition switch on and it puts power through the micro to the relay. Second, check the ground wire on the relay, could be a brown or green wire, if it doesn't make ground the relay won't work even with 12 volts coming in to the relay. For the other part of you problem, the red wire at the relay powers all the lites, including the instrument panel lites but only if the relay itself is working. Now here's where the Opel folks went flakey in the fuse panel. The right three 5 amp fuses don't necessarily power the rest of the lights, they just blow when a circuit has been compromised, some lites on that circuit will still work, others won't. It depends on whether the power comes from the relay or the parking lite switch. I've looked at this for a long time and I still scratch my head and other places trying to figure it out. But power for one side of the fuses does come from the headlight relay, so if it's not working that side of the circuits will be dead. HTH.
 

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Opeler
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190 Posts
I am installing the kwik wire harness on my gt and i am confused with the headlight wiring. Please let me know if i have this correct: the "headlight switch power" will be connected to one of the microswitches in the headlight bucket. The other end of that microswitch will be connected to some 12v source. The headlight and dimmer relay/switches are built into the fuse block of the kwik wiring harness. Then i just connect the high and low beam lines to the headlights and run an extra ground wire into the headlights (because there are three connectors on the back of the headlights and i assume the third wire is ground).

My main confusion is that i am not sure where the headlight and dimmer switch/relay are. If they are built into the fuse block then it should be easy, but i get the feeling that they are not. Please help soon as i need tofinish my opel project in 1 week.
 

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Opeler
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Trying to wrap the project up for the annual migration to El Segundo, eh?

I'm thinking your question is directed more to kwik wire harness experts than GTers because you are not sure if it comes with new relays.

When I rewired mine using the EZ-21, I kept the original headlight and dimmer relays hanging on the front side of the fuse panel box as the rewire kit did not include new relays. The kit had a headlight power wire which I ran to the headlight relay. Then I used the fuel pump wire to provide power to the headlamp relay switch in the left bucket. (By design, my headlights work only when the key is on.) The headlight grounding was unchanged from original.

vancek

I am installing the kwik wire harness on my gt and i am confused with the headlight wiring. Please let me know if i have this correct: the "headlight switch power" will be connected to one of the microswitches in the headlight bucket. The other end of that microswitch will be connected to some 12v source. The headlight and dimmer relay/switches are built into the fuse block of the kwik wiring harness. Then i just connect the high and low beam lines to the headlights and run an extra ground wire into the headlights (because there are three connectors on the back of the headlights and i assume the third wire is ground).

My main confusion is that i am not sure where the headlight and dimmer switch/relay are. If they are built into the fuse block then it should be easy, but i get the feeling that they are not. Please help soon as i need to finish my opel project in 1 week.
 

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Opeler
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190 Posts
Do i need to do anything to the fuel pump wire to make itwork for that microswitch or is it just a 12v line that can work as is?
 

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Opeler
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190 Posts
Thanks so much. I nearly have my electrical done. I am currently living in Saudi Arabia and i have taken a 20 day vacation in order to finish my gt (which i had left as a painted shell). The engine compartment is mostly untouched but everything else was stripped down. Once the electrical is done then its off to a muffler shop followed by an upholstry shop and then into the ship. I am using my jetlag to my advantage to work from 6am till 1am everyday. Wish me luck.
 

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Headlight micro switch by-pass

Can anyone provide an explanation or diagram to show how to by-pass the micro-switch and install an on/off switch for headlight on a 1970 GT? All of you experienced Opelers are great and thanks for your help. Oh, yeah - does anyone else suffer soreness from "Opel Yoga"?
 

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tomking
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Can anyone provide an explanation or diagram to show how to by-pass the micro-switch and install an on/off switch for headlight on a 1970 GT? All of you experienced Opelers are great and thanks for your help. Oh, yeah - does anyone else suffer soreness from "Opel Yoga"?
Opel Yoga? Hell yes.
 
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