Maui Blue

Odd headlight problem.

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Hello folks,

 

I'm hoping I can get some help on an odd headlight malfunction that just cropped up on my 1990 Reatta.

 

In short, both headlight doors go up normally when the dash switch is pushed but they don't come down when headlights are turned off.  At the same time, when the doors go up the headlights do not come on, however I discovered I will get high beams when the high beam lever is activated. Also, if it helps,  the headlight "on" indicator in the dash headlight switch assembly does come on when the switch is on. No other anomalies noted.

 

So far I have checked the headlight breaker in the driver's side fuse box. It reads as a dead short when removed, which I assume is correct.  I also checked all the fuses on the drivers side fuse box just to cover all the bases.  All good. I have also checked the two fuses in the under-hood Relay Center. They both look good. 

 

I understand there is a headlight relay somewhere but it's not shown on the label in the Relay Center, and I don't think it is one of the relays on the firewall so I'm not sure where it is.  If I can find it, is it possible to swap it with another identical relay from another circuit on the car just to test it out?

 

Thanks for any quick assistance.  I'd rather not drive home tonight with the high beams on. :) 

 

Edited by Maui Blue (see edit history)

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The reason the headlights won't go down is because they designed to not go down if a low beam headlight is not burning. In your case it is because the low beams aren't working for some reason. You could have a wire broken going to the headlights near where the headlights pivot. It is pretty common for that to happen.

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11 minutes ago, Ronnie said:

The reason the headlights won't go down is because they won't go down if a low beam headlight is not burning. In your case it is because the low beams aren't working. You could have a wire broken going to the headlights near where the headlights pivot. It is pretty common for that to happen.

 

Thanks for the quick reply.

 

I'll definitely go check that. Would a broken wire on one headlight cause low beams on BOTH headlights not to work?  

 

Or if one of the headlights is bad?

Edited by Maui Blue
clarify (see edit history)

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3 minutes ago, Maui Blue said:

Would a broken wire on one headlight cause low beams on BOTH headlights not to work?

 

I believe so. I think the power goes to one headlight and then on over to the other. I would have to check the service manual to know for sure.

 

The photo below shows where the wires were broken on my car.  As you can see, the headlight connector can be opened to repair the wires.

 

headlight_wire_routing-4.jpg

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Pretty sure Ronnie is on the right track.

Just to make sure,  check the relay........when off,  power goes to the low beam,  when energized, power goes to the high beam.   Since you have high beams, that indicates power is getting to the relay.   Now for the test, pull the relay and with a jumper wire, jumper from pin 1 to pin 3 (if you look at the relay it will have a schematic molded into the cover, you can figure it out) if the relay is bad, the low beams should now be on.

 

I like Ronnies diagnosis.......when the wires to the headlight have been routed incorrectly, they flex at the connector every time the lights go up and down,   This action breaks the stranded wires inside the insulation and you have no light.   the reason both do not work is because power goes to the drivers side connector and then jumpers from the drivers side to the passenger side.  so when the wires fail on the drivers side, both fail.

The solution, go the salvage yard and get a similar headlight plug  and give yourself several inches of wire when you cut it out,  now splice the junk yard connector into your drives side.   I suggest replacing the plug because if you only repair the low beam, the high beam wire or the ground wire may fail shortly. .....since they have all been flexed the same amount.

 

For you and the other Reatta owners.........check the wires going to your headlights ......the wire routing should be UP from the fender side of the casting....over the casting and then plug into the headlight bulb.

If your wires come out of the bulb and go directly down.....that is wrong and you will someday have problems.    See attached picture of correct routing.

upstop III.jpg

Edited by Barney Eaton (see edit history)
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On 1/29/2019 at 5:50 PM, Ronnie said:

 

I believe so. I think the power goes to one headlight and then on over to the other. I would have to check the service manual to know for sure.

 

The photo below shows where the wires were broken on my car.  As you can see, the headlight connector can be opened to repair the wires.

 

headlight_wire_routing-4.jpg

 

OK,  it's dark out right now so I went out and wiggled some wires. No help.  I happen to have an old headlight laying around so I decided to swap one out. When I changed out the driver side headlight that one worked and both doors go up and down now.  The passenger side is still out and I only had one spare. As fate would have it I installed the other light from that spare pair into a friends car on Sunday because one of her low beams had stopped working!

 

I'm hoping I can find another spare light somewhere in my parts junk to install on the other side. I'm hoping that will do the trick.  Otherwise I will come back to this page and try out the other suggestions.

 

I'll let you know either way.

 

Thanks for all the help!!! I really appreciate it.

 

 

Edited to add follow up...

 

Once I replaced both headlights everything worked normally again. Lights work doors work.

Edited by Maui Blue
Follow up. (see edit history)
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