Headlight wiring

bjw6259 · 07-10-2011, 07:48 PM

Hey all,
Adding to the list of problems that I've got on my 89 NA that I paid entirely too much for, one of the headlights recently started acting funny. Sometimes it will go up and down fine, sometimes it won't respond at all when I hit the switch and holds position. At the moment it is stuck up.

I'm hoping it's just a bad connection and am trying to troubleshoot it. I tried setting the switch off and wiggling cables, but no luck. I'd like to buzz out the cables but those harnesses are a pain. So, I am curious, is there a wiring diagram available for the headlights? I'm just curious whether both headlight motors are on a single relay controlled by the headlight switch, or whether there are multiple relays. Could this issue be caused by something bad in the console, or would it have to be way downstream of that?

Oh, and while I'm asking for help, anybody have some good suggestions for loosening RTX? Went to remove my upper intake manifold and found that the previous owner decided to cheap out and use the grey stuff instead of a gasket, and after several hours with a razor blade, I still can't get it to separate. Tried a bit of elbow grease and the soft metal didn't like that much.

FRED · 07-11-2011, 03:51 PM

Both retract motors get their power from the same source and get the control signal from the same source. So if one works fine and the other not so good, the problem lies in the motor assy that is not working right or in the elect connector attached to it.

The power comes off the RETRACT fuse in the engine bay. The control signal comes from the headlight switch and a relay in that switch. Since one headlight assy works right and the other not right, it can't be either of these two items.

Put the headlights to DOWN. Get under the headlight assy and turn the manual knob clockwise or anit clockwise and see if that does or does not make something happen. Should. Keeep your fingers away from the assy when doing that. And or disconnect the elect connector from the motor.........examine if for faults.........put it back on and try again. And or give it a light rap with?????? and see if it responds. There's relays in those assy's that might be stuck, corroded.

LIke I said, the power and control signals come from the same source and the right and left hand side has those wires spliced together inside the harness so if one works, the other should unless that one headlight assy is at fault. Common sense thing.

bjw6259 · 07-11-2011, 06:06 PM

Why I couldn't find that myself during my pass through the FSM, I will never know. Appreciate the help, looks like I've got my work cut out. Here's hoping I don't have to buy a new motor.

NoDOHC · 07-11-2011, 06:39 PM

Try reaching under the car and turning the little knob on the headlight motor, sometimes a twist is all it needs. If mine has been sitting for a long time, I have to do this sometimes until the motors get some use and the corrosion goes away.

(In other words, in may be a clearing switch, not a wiring problem).

FRED · 07-12-2011, 12:19 PM

It shouldn't be that hard to figure out. Pull the plug off the unit. Turn the headlights to UP. With a meter check the R/L or red/blue wire for power. Should be there.

Then put the headlights to Down and check the R/Y or red/yellow wire for power. Should be there.

And check the pure black wire for showing less than one ohm.

Check the White/Green for power 24/7. Should be there. IF all four are there.........motors the problem or the relays in the motors.

Wiring diagrams are usually off by themselves in the FSM. Or sometimes it pays to go to the Body Electrical part of the FSM for trouble shooting.

FRED · 07-12-2011, 12:28 PM

Try this site for RX wiring diagrams: http://foxed.ca/foxed/index.php?page...nual#secondgen I don't use it but it is referred to often. Go to the one that specifically says WIRING DIAGRAMS and not the one that says FSM.

07-10-2011, 07:48 PM	#1
bjw6259 The Newbie Join Date: Jul 2011 iTrader: (0) Posts: 3 Rep Power: 0	Headlight wiring Hey all, Adding to the list of problems that I've got on my 89 NA that I paid entirely too much for, one of the headlights recently started acting funny. Sometimes it will go up and down fine, sometimes it won't respond at all when I hit the switch and holds position. At the moment it is stuck up. I'm hoping it's just a bad connection and am trying to troubleshoot it. I tried setting the switch off and wiggling cables, but no luck. I'd like to buzz out the cables but those harnesses are a pain. So, I am curious, is there a wiring diagram available for the headlights? I'm just curious whether both headlight motors are on a single relay controlled by the headlight switch, or whether there are multiple relays. Could this issue be caused by something bad in the console, or would it have to be way downstream of that? Oh, and while I'm asking for help, anybody have some good suggestions for loosening RTX? Went to remove my upper intake manifold and found that the previous owner decided to cheap out and use the grey stuff instead of a gasket, and after several hours with a razor blade, I still can't get it to separate. Tried a bit of elbow grease and the soft metal didn't like that much.

07-11-2011, 06:39 PM	#4
NoDOHC The quest for more torque Join Date: Sep 2008 Location: Sheboygan, Wisconsin iTrader: (1) Posts: 855 Rep Power: 17	Try reaching under the car and turning the little knob on the headlight motor, sometimes a twist is all it needs. If mine has been sitting for a long time, I have to do this sometimes until the motors get some use and the corrosion goes away. (In other words, in may be a clearing switch, not a wiring problem). __________________ 1986 GXL ('87 4-port NA - Haltech E8, LS2 Coils. Defined Autoworks Headers, Dual 2.5" Exhaust (Dual Superflow, dBX mufflers) 1991 Coupe (KYB AGX Shocks, Eibach lowering springs, RB exhaust, Stock and Automatic)

07-12-2011, 12:28 PM	#6
FRED Rotary Fan in Training Join Date: Mar 2011 iTrader: (0) Posts: 73 Rep Power: 14	Try this site for RX wiring diagrams: http://foxed.ca/foxed/index.php?page...nual#secondgen I don't use it but it is referred to often. Go to the one that specifically says WIRING DIAGRAMS and not the one that says FSM. Last edited by FRED; 07-12-2011 at 12:30 PM..

07-11-2011, 06:06 PM	#3
bjw6259 The Newbie Join Date: Jul 2011 iTrader: (0) Posts: 3 Rep Power: 0	Why I couldn't find that myself during my pass through the FSM, I will never know. Appreciate the help, looks like I've got my work cut out. Here's hoping I don't have to buy a new motor.

07-12-2011, 12:19 PM	#5
FRED Rotary Fan in Training Join Date: Mar 2011 iTrader: (0) Posts: 73 Rep Power: 14	It shouldn't be that hard to figure out. Pull the plug off the unit. Turn the headlights to UP. With a meter check the R/L or red/blue wire for power. Should be there. Then put the headlights to Down and check the R/Y or red/yellow wire for power. Should be there. And check the pure black wire for showing less than one ohm. Check the White/Green for power 24/7. Should be there. IF all four are there.........motors the problem or the relays in the motors. Wiring diagrams are usually off by themselves in the FSM. Or sometimes it pays to go to the Body Electrical part of the FSM for trouble shooting.