1989 Reatta Headlight Door Module

[Guest]

I am working on a '89 Reatta and have determined that the Headlight Door Module is not functioning properly. Does anyone know the if other Buick/GMC headlight Door Module are compatiable?<P>Mike, Cleveland, Ohio

[Barney Eaton]

I have a good used module that I purchased because I thought we had a bad original.<BR>It was not the problem. I paid $20 plus shipping. I will sell it for the same price.<P>What makes you think you need to replace the module?

[Guest]

Dear Barney,<P>Thank you for reply, but more importantly thank you for the brilliant work you are doing with your discussion web page. It takes a lot of determination and self-satisfaction to keep such a project (web page) running. So far this is the best discussion group I have found for Reatta owners.<P>Here is the discrepancy I am experiencing with a ’89 Reatta. The passenger’s side headlight door does not open or close. I tried cycling the doors with the headlight switch and headlight door switch, neither outcome opens or closes the passenger door, the drivers side door functions properly utilizing either switch (parking light-headlight door). Also both headlights came on even the passenger, which stayed on while the door was closed.<P><BR>Got my hands on a factory manual, did some reading/research then took my multi meter and did some testing. I am able to manually raise and lower the door, noted no discrepancies or mechanical bindings. I began with the obvious, checking fuses in the car interior, no blown fuse; only the power antenna fuse was removed since the antenna motor run constantly. After reading your antenna discussion area, I suspect the plastic antenna cord is broke, another weekend project for the future. Back to the headlight door. I disconnected the headlight motor from the chassis electrical system and ran a continued thru the motor, all check out fine. I hooked up an external power source to the motor and successfully open and closed the door, once again noted no mechanical discrepancies but I was unable to monitor how much current it took to raise and lower the door. Should have hooked up an ammeter, oh well. <BR>Next I began to back track from there. I inspected the underhood fuse rely box and discovered a blown fuse, did not pay attention to which one but was probably the passenger fuse. R&R the fuse and still the door did not function properly. Back tracked once again to the module. Knowing the only way to check this component was to monitor the voltage in and voltage out, read in book cannot measure resistance with this module. I hooked up my meter to the input side (connector C1) and measured voltage and measured about 9 volts thru both wires; yellow and yellow black wires, while cycling headlight switch that is located left of the instruments panel. I concluded checking of the C1 connection fuse wires, orange and orange w/black stripe wires, and noted voltage on both wires.<BR>Next step was to measure what’s coming out of the module (C2 connector), so I measured the driver’s side voltage while cycling the door and noted positive voltage to open and negative voltage to close, this is the correct results expected (utilizing headlight switch). When I hooked up the meter to the green and gray wires for the passenger door, I noted no power in either position of the instrumental switch. Stopped the trouble-shooting efforts right there. I suspect with the blown fuse and no power coming out, I concluded that this maybe the problem. If I put a fully functional module in the car, I will know if I am correct or not and if so continue on with back tracking.<P>Any other ideas or have I overlooked the obvious?<BR>Mike from Cleveland

[Barney Eaton]

Very good. You pretty much verified that it is the module.<P>Since it sounds like you actually pulled the relay box to get to the module, one last suggestion. Since green/white and green/black are working for the left door, pull the connector and jumper from module terminal C & D to the right headlight connector.<P>With all your testing it appears the right door side of the module is dead. This would just verify that the left driver would open and close the right door.<P>It may not be worth the effort...since you have done such a good job of tracking down the problem.

[Guest]

Barney,<P>The owner is interested in purchasing the headlight module. I tried emailing you at BARNEY@TEXAS.NET.<P>Mike from Cleveland

[oldasdirt]

hi.....excuse my ignorance, but where are the fuses and relays to the doors????? I do not have a shop manual. I would think there is one for the right and one for the left.I just put new bushing in mine. They were functioning fine, the the passenger side just stopped. I put grease on the gears as per the directions. it didn't appear to have grease whn I took the assembly apart, but after 30 years, thought it just dried up. Any input would be great.

[Barney Eaton]

Look in the "Relay" box....just in front of the air cleaner and you will find 2 fuses,  one for each headlight...... no relays, just the headlight module located under the relay box.

lube is not an issue on the gear,  it appears a glob of grease was put on the worm when the motors were made,  but I have seen very little wear on the big white gear.

Oil the bronze bearings,  clean the "O" rings,  and I do put a little grease on the end of the worm gear  where the ball (thrust) bearing is located.

Edited August 11, 2018 by Barney Eaton (see edit history)