Headlight goes up but won't come back down..
#1
Headlight goes up but won't come back down..
hey guys i have an 86 trans am and when i turn on the head lightsthey both come up fine but only the passenger side goes back down. if i pop the hood turn the **** a little it goes back down just fine. What could be causing it to have power on the way up but not back down?
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Contact board sponsor Lon Salgren at Top Down Solutions Top-DownSolutions.com for all your headlight motor help.
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Car: '91 Z28 convertible
Engine: TPI
Transmission: T5
Axle/Gears: 3.27 posi disc
The problem might be in the "actuator relay". No idea where it's located (never seen an '86 Bird under the hood) but it will have 5 leads: red/white, pink, black, gray/black, green/white. There are two relays under the hood, probably next to each other and probably on the firewall but you're looking for this one, which controls the driver side.
You can try to clean the contacts and tug on the wires and see if it makes the light go down. You can also try to swap it with the other relay and see if the problem transfers to the other headlight.
Hope it helps.
And keep us posted!
Lou
You can try to clean the contacts and tug on the wires and see if it makes the light go down. You can also try to swap it with the other relay and see if the problem transfers to the other headlight.
Hope it helps.
And keep us posted!
Lou
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Car: 87 GTA
Engine: L98
Transmission: 700R4
Axle/Gears: Dana M78 3.27 posi
Lou can solve it...I just had the exact opposite problem. Went down by itself, but not up.
I think the wires Lou is referring to, it that control module on the firewall, with two connectors. Mine turned out to be a old alarm had been uninstalled, and the wiring affecting the lights was falling apart. Literally, the wires came apart after the electrical tape was removed. They had never been soldered together. Lou took care of that.
I think the wires Lou is referring to, it that control module on the firewall, with two connectors. Mine turned out to be a old alarm had been uninstalled, and the wiring affecting the lights was falling apart. Literally, the wires came apart after the electrical tape was removed. They had never been soldered together. Lou took care of that.
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Car: '91 Z28 convertible
Engine: TPI
Transmission: T5
Axle/Gears: 3.27 posi disc
Steve, thank you for the kind words.
Thought, you have a slightly newer model with differnt headlight motor control. The 86's had actuator relays and another relay module. It's not guaranteed that it's all on the firewall and in one piece. I'd guess it's three boxes anywhere under the hood.
Hopefully somebody with detailed knowledge of an '86 underhood layout will chime in.
Lou
Thought, you have a slightly newer model with differnt headlight motor control. The 86's had actuator relays and another relay module. It's not guaranteed that it's all on the firewall and in one piece. I'd guess it's three boxes anywhere under the hood.
Hopefully somebody with detailed knowledge of an '86 underhood layout will chime in.
Lou
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#8
Originally Posted by BigBabyLou
Steve, thank you for the kind words.
Thought, you have a slightly newer model with differnt headlight motor control. The 86's had actuator relays and another relay module. It's not guaranteed that it's all on the firewall and in one piece. I'd guess it's three boxes anywhere under the hood.
Hopefully somebody with detailed knowledge of an '86 underhood layout will chime in.
Lou
Thought, you have a slightly newer model with differnt headlight motor control. The 86's had actuator relays and another relay module. It's not guaranteed that it's all on the firewall and in one piece. I'd guess it's three boxes anywhere under the hood.
Hopefully somebody with detailed knowledge of an '86 underhood layout will chime in.
Lou
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Car: 87 GTA
Engine: L98
Transmission: 700R4
Axle/Gears: Dana M78 3.27 posi
Let's seee...No promises since mine is a '87 but...
In the third pic, the single relay circled in green, is identical in location to my fog light relay. ATGO has a mod that allows the fog lights to stay on with the high beams. I didn't even realize my fog lights went off with the high beams on! VERY simple change. Snip one wire, ground it, and cover the other end.
Fog Lights on with high beam mod
That set up on the firewall is definately different from mine. Sorry, can't help you past this.
Good luck!
You might be able to take your pic to a GM stealership, and see if they can identify the parts, then just balk at the price, and say you'll hafta wait until payday.
In the third pic, the single relay circled in green, is identical in location to my fog light relay. ATGO has a mod that allows the fog lights to stay on with the high beams. I didn't even realize my fog lights went off with the high beams on! VERY simple change. Snip one wire, ground it, and cover the other end.
Fog Lights on with high beam mod
That set up on the firewall is definately different from mine. Sorry, can't help you past this.
Good luck!
You might be able to take your pic to a GM stealership, and see if they can identify the parts, then just balk at the price, and say you'll hafta wait until payday.
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Car: 87 GTA
Engine: L98
Transmission: 700R4
Axle/Gears: Dana M78 3.27 posi
Well...
#2 is...
GMC (88-82) Cars & Trucks
OE#'S: 14047112, 14073417, 14078902
Radiator Fan
So, #2 isn't it...
#3 has a vaccum line, so doubtful that is it...
Check the wire colors on the headlight motor, and see if you can find a match on a relay. Unplug both ends, then run a continuity test to see if you can match them.
Give me the part #s on the others, and I'll see what I can find.
My bet is the big one on the left, last pic, largish box, #1. Looks like a ?BL...? on it.
#2 is...
GMC (88-82) Cars & Trucks
OE#'S: 14047112, 14073417, 14078902
Radiator Fan
So, #2 isn't it...
#3 has a vaccum line, so doubtful that is it...
Check the wire colors on the headlight motor, and see if you can find a match on a relay. Unplug both ends, then run a continuity test to see if you can match them.
Give me the part #s on the others, and I'll see what I can find.
My bet is the big one on the left, last pic, largish box, #1. Looks like a ?BL...? on it.
Last edited by Stephen; 07-29-2006 at 10:59 PM.
#13
Originally Posted by Stephen
Well...
#2 is...
GMC (88-82) Cars & Trucks
OE#'S: 14047112, 14073417, 14078902
Radiator Fan
So, #2 isn't it...
#3 has a vaccum line, so doubtful that is it...
Check the wire colors on the headlight motor, and see if you can find a match on a relay. Unplug both ends, then run a continuity test to see if you can match them.
Give me the part #s on the others, and I'll see what I can find.
My bet is the big one on the left, last pic, largish box, #1. Looks like a ?BL...? on it.
#2 is...
GMC (88-82) Cars & Trucks
OE#'S: 14047112, 14073417, 14078902
Radiator Fan
So, #2 isn't it...
#3 has a vaccum line, so doubtful that is it...
Check the wire colors on the headlight motor, and see if you can find a match on a relay. Unplug both ends, then run a continuity test to see if you can match them.
Give me the part #s on the others, and I'll see what I can find.
My bet is the big one on the left, last pic, largish box, #1. Looks like a ?BL...? on it.
i also found this site that says #4 could be the one but the pics dont match up completely. 3rd° Tech Tips~MAF Relay Location
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Car: 87 GTA
Engine: L98
Transmission: 700R4
Axle/Gears: Dana M78 3.27 posi
Well...
Baldwin-Lima-Hamilton or BLH, so that's just the manufacturer name...If we had the part # on it, we could search further. I still bet it is the one we want.
If #4 is YOUR fog light relay, it doesn't make sense. You have an identical relay to my 87 GTA by the windshield washer bottle, which is DEFINATELY my fog light relay. I've already modded mine, thanks to Lou for knowing how to do that, to run my fog lights with my high beams on.
Baldwin-Lima-Hamilton or BLH, so that's just the manufacturer name...If we had the part # on it, we could search further. I still bet it is the one we want.
If #4 is YOUR fog light relay, it doesn't make sense. You have an identical relay to my 87 GTA by the windshield washer bottle, which is DEFINATELY my fog light relay. I've already modded mine, thanks to Lou for knowing how to do that, to run my fog lights with my high beams on.
#15
Originally Posted by Stephen
Well...
Baldwin-Lima-Hamilton or BLH, so that's just the manufacturer name...If we had the part # on it, we could search further. I still bet it is the one we want.
If #4 is YOUR fog light relay, it doesn't make sense. You have an identical relay to my 87 GTA by the windshield washer bottle, which is DEFINATELY my fog light relay. I've already modded mine, thanks to Lou for knowing how to do that, to run my fog lights with my high beams on.
Baldwin-Lima-Hamilton or BLH, so that's just the manufacturer name...If we had the part # on it, we could search further. I still bet it is the one we want.
If #4 is YOUR fog light relay, it doesn't make sense. You have an identical relay to my 87 GTA by the windshield washer bottle, which is DEFINATELY my fog light relay. I've already modded mine, thanks to Lou for knowing how to do that, to run my fog lights with my high beams on.
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Car: 87 GTA
Engine: L98
Transmission: 700R4
Axle/Gears: Dana M78 3.27 posi
Have you tried unplugging only 1 relay at a time, to see the results? Then reconnecting it, then disconnecting it a few times, to verify it is the relay causing the light motor misbehavior, if it happens, and not be a coincidence?
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Car: '91 Z28 convertible
Engine: TPI
Transmission: T5
Axle/Gears: 3.27 posi disc
If you can't find the relay, you can measure the voltage across the motor wires at the motor connector while you turn the headlights on and off.
Let us know what you find out.
Lou
Let us know what you find out.
Lou
#18
No i have'nt done that but i just went out there and inpluged the motor and hooked it straight up to the battery to verify that the motor works both ways and indeed it does.... so now i just have to figure out why the relay is letting it go up but not back down, and where the heck this relay is for sure.
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Car: 1987 Formula (original owner)
Engine: 305 TPI
Transmission: T5
Axle/Gears: 9-bolt/3.45
From the top:
Pic 2, driver's side, forward of the firewall relays, on the fender is the foglight relay.
Pic 3, driver's side, on the fender by the washer tank is the relay(circled) for the headlight on that side.
Pic 4, passenger side, on the fender by the coolant tank is the relay(circled) for the headlight on that side(same part number as the other).
Tracing the wires from each relay, you'll find that they go to(or come from) a similar-looking relay located at the base of the radiator, passenger side, near the fan relays. This one is the source relay, might even be the same part number again, or numerically similar.
Headlight motors and relay set-up is very different between the '82-'86 cars and the '87+ cars. The TDS kit is for '87+ headlight motors. There might be one now for the earlier years, but I don't think so, which might be why the instructions you have aren't matching up to and working for your '86 headlight motors.
Disconnect, clean and reconnect each relay. Often that's all that's needed.
Edit - Ok, I see below that TDS does offer gear repair kits for the '82-'86 headlight motors now.
Pic 2, driver's side, forward of the firewall relays, on the fender is the foglight relay.
Pic 3, driver's side, on the fender by the washer tank is the relay(circled) for the headlight on that side.
Pic 4, passenger side, on the fender by the coolant tank is the relay(circled) for the headlight on that side(same part number as the other).
Tracing the wires from each relay, you'll find that they go to(or come from) a similar-looking relay located at the base of the radiator, passenger side, near the fan relays. This one is the source relay, might even be the same part number again, or numerically similar.
Headlight motors and relay set-up is very different between the '82-'86 cars and the '87+ cars. The TDS kit is for '87+ headlight motors. There might be one now for the earlier years, but I don't think so, which might be why the instructions you have aren't matching up to and working for your '86 headlight motors.
Disconnect, clean and reconnect each relay. Often that's all that's needed.
Edit - Ok, I see below that TDS does offer gear repair kits for the '82-'86 headlight motors now.
Last edited by LAFireboyd; 07-30-2006 at 04:03 PM.
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The following applies for 1982-86 (aka three-wire) headlight actuators. It doesn't apply for 1987-92 (aka two-wire) headlight actuators.
If both headlight doors won't close, then look at the following: A blown 20 amp tail light fuse, bad isolation relay or bad connection or ground.
If one headlight motor won't close, then look at the following: A bad isolation relay, bad connection or ground, faulty actuator motor limit switch or bad actuator motor.
If both headlight doors won't open, then look at the following: A blown main fuse link to the headlight switch, a bad isolation relay or a bad connection or ground.
If one headlight door won't open, then look at the following: A bad actuator relay, a blown actuator relay fuseable link, bad connection or ground, faulty actuator motor limit switch or a bad actuator motor.
The isolation relay is on the frame of the car next ot the drivers-side headlight mechanism. The isolation relay controls both headlight actuators. If the motor continuously runs, but doesn't move the headlight bucket up or down, then you have a stripped gear. I sell a repair kit with a brass CNC machined gear as TDS 508210. I also include instructions and a troubleshoot guide (where the recommendations I've listed above came from).
Good luck,
Lon
If both headlight doors won't close, then look at the following: A blown 20 amp tail light fuse, bad isolation relay or bad connection or ground.
If one headlight motor won't close, then look at the following: A bad isolation relay, bad connection or ground, faulty actuator motor limit switch or bad actuator motor.
If both headlight doors won't open, then look at the following: A blown main fuse link to the headlight switch, a bad isolation relay or a bad connection or ground.
If one headlight door won't open, then look at the following: A bad actuator relay, a blown actuator relay fuseable link, bad connection or ground, faulty actuator motor limit switch or a bad actuator motor.
The isolation relay is on the frame of the car next ot the drivers-side headlight mechanism. The isolation relay controls both headlight actuators. If the motor continuously runs, but doesn't move the headlight bucket up or down, then you have a stripped gear. I sell a repair kit with a brass CNC machined gear as TDS 508210. I also include instructions and a troubleshoot guide (where the recommendations I've listed above came from).
Good luck,
Lon
#21
Originally Posted by lonsal
The following applies for 1982-86 (aka three-wire) headlight actuators. It doesn't apply for 1987-92 (aka two-wire) headlight actuators.
If both headlight doors won't close, then look at the following: A blown 20 amp tail light fuse, bad isolation relay or bad connection or ground.
If one headlight motor won't close, then look at the following: A bad isolation relay, bad connection or ground, faulty actuator motor limit switch or bad actuator motor.
If both headlight doors won't open, then look at the following: A blown main fuse link to the headlight switch, a bad isolation relay or a bad connection or ground.
If one headlight door won't open, then look at the following: A bad actuator relay, a blown actuator relay fuseable link, bad connection or ground, faulty actuator motor limit switch or a bad actuator motor.
The isolation relay is on the frame of the car next ot the drivers-side headlight mechanism. The isolation relay controls both headlight actuators. If the motor continuously runs, but doesn't move the headlight bucket up or down, then you have a stripped gear. I sell a repair kit with a brass CNC machined gear as TDS 508210. I also include instructions and a troubleshoot guide (where the recommendations I've listed above came from).
Good luck,
Lon
If both headlight doors won't close, then look at the following: A blown 20 amp tail light fuse, bad isolation relay or bad connection or ground.
If one headlight motor won't close, then look at the following: A bad isolation relay, bad connection or ground, faulty actuator motor limit switch or bad actuator motor.
If both headlight doors won't open, then look at the following: A blown main fuse link to the headlight switch, a bad isolation relay or a bad connection or ground.
If one headlight door won't open, then look at the following: A bad actuator relay, a blown actuator relay fuseable link, bad connection or ground, faulty actuator motor limit switch or a bad actuator motor.
The isolation relay is on the frame of the car next ot the drivers-side headlight mechanism. The isolation relay controls both headlight actuators. If the motor continuously runs, but doesn't move the headlight bucket up or down, then you have a stripped gear. I sell a repair kit with a brass CNC machined gear as TDS 508210. I also include instructions and a troubleshoot guide (where the recommendations I've listed above came from).
Good luck,
Lon
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