89 Headlight issue.....searched but need confirmation
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Joined: Oct 2011
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89 Headlight issue.....searched but need confirmation
I have searched the forum and think I have found the answer but I want to make sure I am thinking correctly. On my dad's 89, the pass side headlight motor doesn't seem to be getting power. The wires look okay. And when I jump power straight to it, it will open. After searching here, I am thinking that it is the headlight isolation relay on the driver's side wheel well. Am I correct in my thinking? Is there a good place to buy with a cheaper price?
I had to replace the headlight bushings on the driver's side using the information here. The motor itself seems to be okay on the pass side...just getting no power. Thanks
I had to replace the headlight bushings on the driver's side using the information here. The motor itself seems to be okay on the pass side...just getting no power. Thanks
Melting Slicks
Joined: Aug 1999
Posts: 2,240
Likes: 42
From: Baltimore, MD USA
The 89 uses a headlight control module mounted to the front
of the driver side plastic wheel well housing.
To close the headlight bucket, 12 volts for the motor comes
from the headlight switch. To open the headlight bucket,
12 volts comes from two fusible links. One for each
motor. The fusible links are hot all the time and also provide
12 volts to power the headlight control module.
You can unplug the electrical connector at the module
and verify there is 12 volts from each fusible link.
If you look below and behind the battery, you will see
a bunch of orange colored wires bolted to a stud.
That's where the fusible links originate from.
Here's the schematic.
of the driver side plastic wheel well housing.
To close the headlight bucket, 12 volts for the motor comes
from the headlight switch. To open the headlight bucket,
12 volts comes from two fusible links. One for each
motor. The fusible links are hot all the time and also provide
12 volts to power the headlight control module.
You can unplug the electrical connector at the module
and verify there is 12 volts from each fusible link.
If you look below and behind the battery, you will see
a bunch of orange colored wires bolted to a stud.
That's where the fusible links originate from.
Here's the schematic.
Last edited by Hooked on Vettes; Nov 6, 2011 at 04:16 PM.
Thread Starter
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Joined: Oct 2011
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Okay, I just went out and checked the voltage on the 5 pin plug that plugs into the Headlight Control Module and both sides were getting power. So now I guess I am back to the module being bad. The motor works and the power is reaching the module.
Melting Slicks
Joined: Aug 1999
Posts: 2,240
Likes: 42
From: Baltimore, MD USA
I know you said you removed the connector and did
the voltage measurements. You could try
resetting the module by disconnecting the negative
battery cable for a couple of seconds.
When you reconnect the negative battery cable, you
should hear two clunk noises coming from the headlight
motors. That's the sound from the motors as they are
driven to the closed position.
Used modules are around $50.00. New ones are around
$150.00.
Modules from a 88-96 will work.
Do a search in the C4 parts section for headlight control module.
Here's one for sale.
http://forums.corvetteforum.com/c4-p...-c4-items.html
the voltage measurements. You could try
resetting the module by disconnecting the negative
battery cable for a couple of seconds.
When you reconnect the negative battery cable, you
should hear two clunk noises coming from the headlight
motors. That's the sound from the motors as they are
driven to the closed position.
Used modules are around $50.00. New ones are around
$150.00.
Modules from a 88-96 will work.
Do a search in the C4 parts section for headlight control module.
Here's one for sale.
http://forums.corvetteforum.com/c4-p...-c4-items.html
Last edited by Hooked on Vettes; Nov 6, 2011 at 09:20 PM.
Thread Starter
Navigator
Joined: Oct 2011
Posts: 9
Likes: 0
Okay, I bought a module off of here and it fixed the opening issue. Now the problem is the light that was not opening (that the module fixed) has a motor that continues to turn after the light is up....I'm thinking that I probably need to replace the bushings in this motor as well??
Melting Slicks
Joined: Aug 1999
Posts: 2,240
Likes: 42
From: Baltimore, MD USA
Yes you need to install the bushings.
The control module monitors the current draw of the motor.
If the motor keeps spinning the control module thinks the headlight
bucket hasn't reached the fully open or fully closed position.
The same bushing is used to repair Ford power window motors.
You can find them in the Help isle of most auto part stores.
http://shop.advanceautoparts.com/web...7CGRP2037_____
The control module monitors the current draw of the motor.
If the motor keeps spinning the control module thinks the headlight
bucket hasn't reached the fully open or fully closed position.
The same bushing is used to repair Ford power window motors.
You can find them in the Help isle of most auto part stores.
http://shop.advanceautoparts.com/web...7CGRP2037_____
Last edited by Hooked on Vettes; Nov 22, 2011 at 09:31 PM.
