headlight motor power problem
Thread Starter
4th Gear
Joined: Sep 2002
Posts: 4
Likes: 0
From: Plano TX
headlight motor power problem
I have a 94 Coupe. Recently replaced the RH headlight motor bushings. When I reinstalled the actuator motor, there was no power to the it. There was power before I replaced bushings and motor worked fine. Have verified motor works by testing on LH side. Motor power for RH comes from 2 blue wires on headlight wire gang. Verified no voltage on motor wires with voltmeter. Is there a relay or something that could go out that would stop the voltage to headlight motor? Have checked fuses too and they're OK. What else could cause this?
(Bonus question: Why does another problem always pop up when you fix one problem? When it rains it pours.)
Thanks, Winky 94 C4.
:flag
(Bonus question: Why does another problem always pop up when you fix one problem? When it rains it pours.)
Thanks, Winky 94 C4.
:flag
Team Owner
Joined: Mar 2001
Posts: 54,124
Likes: 30
From: Cincinnati, Oh USA
Re: headlight motor power problem (racersedge52)
Yes there is a relay that supplies 12v to the correct wires on the motor to open the headlight door. There is another relay that applies 12v to the correct wires on the motor to close the door. On my 87 the opening relay is mounted on the RH side near the headlight. The closing relay is mounted over on the LH side near the LH headlight.
Follow the wires from the motor connector to find the relays .
[Modified by jfb, 10:39 AM 9/24/2002]
Follow the wires from the motor connector to find the relays .
[Modified by jfb, 10:39 AM 9/24/2002]
Melting Slicks
Joined: Feb 2002
Posts: 2,699
Likes: 2
From: The Black Hole LA
Re: headlight motor power problem (jfb)
that's wierd they must have changed relay locations because on my 86 all three relays are on the driver side mounted to the inside of the fender well under the light. One for power, the other two control each light. If one light will work but the other one will not, as happenned to me it is not the main power relay.
Thread Starter
4th Gear
Joined: Sep 2002
Posts: 4
Likes: 0
From: Plano TX
Re: headlight motor power problem (hz900)
Thanks for your reply. Yes, they changed to a two-wire system in the 90's. The power leads to the right actuator are blue and green to the left. I'm not yet sure where a relay is that might cause the power to go out to an actuator motor. If you find out for my model (94), let me know. Thanks again. :cheers:
[Modified by racersedge52, 9:09 PM 9/24/2002]
[Modified by racersedge52, 9:09 PM 9/24/2002]
Melting Slicks
Joined: Feb 2002
Posts: 2,699
Likes: 2
From: The Black Hole LA
Re: headlight motor power problem (racersedge52)
You might want to try the search feature, I'm sure someone has had this problem on a late C4. Good luck, wiring probs are always a PITA.
Racer
Joined: Nov 2000
Posts: 415
Likes: 0
From: mauriceville texas
Re: headlight motor power problem (racersedge52)
this just happened on my 92. there is a headlight controll module. it sits in front of the driver front wheel. there are two 10 mm headed bolts that hold it on. they come in from the lower front fender well directly in front of the tire. it has 2 pig tails 1 to each motor. it decides what wire to send voltage to so the lights go up and down. its a little expensive mine was 148.00 at the local chevy dealer. hope this helps robert
Thread Starter
4th Gear
Joined: Sep 2002
Posts: 4
Likes: 0
From: Plano TX
Re: headlight motor power problem (robert kirk)
yes, this appears to be my problem too; i checked the voltage and only the left side is getting current; do you know the part number for the headlight control module? thanks for replying
:smash:
:smash:
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Racer
Joined: Nov 2000
Posts: 415
Likes: 0
From: mauriceville texas
Re: headlight motor power problem (JonM)
on mine the module was 8 inches square and about 1 inch thick with 2 pig tails pluged in on the flat side. gm part # 16521297. hope this helps, this module tells the motor witch way to turn.
Thread Starter
4th Gear
Joined: Sep 2002
Posts: 4
Likes: 0
From: Plano TX
Re: headlight motor power problem (JonM)
Thanks for you reply. This appears to be either the automatic headlight relay or the relay system for older 3 wire headlight door actuator controlers; the solution to my problem was the module that is located on the left front wheel well; this is called the 'headlight door module', GM part 16521297. It can fit older (pre-92) if converted to the two wire system. Thanks again. :yesnod:
