How do I access the wiring in the roof - 2002 GMC Yukon XL

It will not show up with a typical P code from Autozone. It might show up with a dedicated code reader for specifically BMW. My code reader with BMW extended program does not show it. To trouble shoot this without a BMW code reader, try your buttons first, if you do not hear a motor noise, then you need to check if motor is getting power when button is pressed. Take of access panel in center of roof forward near rear view mirror. You will be able to access the motor there. Probe the electrical connections going to the motor and have someone push the buttons. Review the meter while buttons are pressed to see if motor is getting approx. 12 volts. If so then the motor may be dead. If there is not activity at the motor as far as 12 volts, then you have an electrical supply issue which could be several options: Electrical wiring, loose plug somewhere, a bad fuse (most common), a bad switch (probably not if both switches do not respond to electrical test), or a bad relay. Remember to check the truck are for the roof storage panel. If this is in the up position it will not allow enough roof for roof the store in truck and will not allow roof to move, retract.

try a spray lubricant into the motor mechanism and grease any visable wire cables that run from/to motor ,not the electrical cables the bare wire winder cables,also grease/ lubricate any accessable pivot/hinge points , gently pull the cord and gently push the roof back and forth occasionally trying motor with a bit of patience this should get the roof moving , also look for anything that may be snagging the roof/mechanism as there is a pressure protection system to stop the roof being fully closed on say someones hand so preventing injury

A job for the dealer, this top is computer controlled. The system needs to be scanned with a special electronic system tool.

I have same problem. Below are a couple of suggestions from LincolnOnLine.com on how to close the sunroof manually. The first relates to a '93 and I'm not sure about the second. Use this info at your own risk. If you get a better answer, PLEASE POST IT HERE FOR ME. Thanks. Mort


Here is the text from my 93 Manual. There is an access panel in the rear centre of the headliner if it is the same as my 93.

Manual Operation

To close the sliding panel manually, remove the roof access hole trim panel located at the rear of the moon roof assembly. Remove the motor and bracket assembly as outlined to expose the splined shaft of the moon roof drive gear box. Using a typical corporate door window regulator crank handle properly set on the splined shaft, crank the moon roof panel closed.

Motor

CAUTION:
It is recommended that the battery ground cable be disconnected when removing or installing the moon roof motor assembly.


Removal and Installation

1. Operate glass panel until rear of glass panel is flush with sheet metal surface.

2. Remove motor access cover.

3. Remove two motor retaining screws.

4. Lower motor away from splined motor gear and disconnect electrical connector.

5. To install, reverse Removal procedure and synchronize motor as outlined under Adjustments.

Good Luck! __________________
Current:<P>1995 Town Car Executive 80K Miles<BR>1990 Mustang LX 2.3 Auto 62K<BR>1985 Chevrolet Caprice Estate Wagon X 2 (160K & 100K)<BR>1983 Chevrolet Caprice Sedan<BR>1984 Renault Turbo Fuego 60K<P>Past<BR> <BR>1980 Oldsmobile Cutlass<BR>1980 Chevrolet Citation<BR>1974 Triumph Spitfire<BR>1968 Triumph Spitfire<BR>1957 MGA<BR>1966 Renault R8<BR>1966 Renault R10<BR>1974 Chevrolet Malibu<BR>1968 Pontiac Firebird<BR>1966 Honda S600 Converible w Hardtop<BR>1978 Bobcat<BR>1969 Buick Last edited by Thanet; January 8th, 2007 at 07:07 PM. #3 January 8th, 2007, 07:26 PM Bill M. Registered User Join Date: January 8th, 2007 Location: Boston, MA Posts: 3 Moonroof Woes Thanks for the moonroof help. I might be getting a switch in the a.m. If not that remedy doesn't sound too bad. Bill M. #4 January 8th, 2007, 09:49 PM Tman70 Moderator Join Date: July 26th, 2004 Location: New York Posts: 2,757 1. Remove the roof headlining access hole cover located at the rear of the roof headlining.

2. Remove the sliding roof panel motor as outlined to expose the splined shaft of the sliding roof rail and guide.

3. Crank theroof sliding outer glass panel closed using a typical corporate door window regulator crank handle properly set on the splined shaft.

4. After performing these operations, remove crank handle and retime as outlined. Refer to «Adjustments, Motor Synchronization (Timing)» .

5. Install the sliding roof panel motor.

6. Tighten to 4-6 N-m (36-53 lb-in) and install roof headlining access hole cover. __________________

You will have to remove the headliner to gain access to the motor. With the switch engaged test the wiring at the motor connections to see if the motor is getting power. If it is then I'd say replace the motor. These motors commonly go bad because of the extreme heat they are exposed to by being mounted on the inside of the roof.

check fuse F1.401, 30 amp in central junction box (in truck). Check your owner manual for fuse information.
Headliner must be removed to access motor.



Visual Inspection Chart Mechanical Electrical

• Roof opening panel
• Roof opening panel frame
• Roof opening panel drain hoses
• Roof opening panel lifter assemblies
• Roof opening panel water trough
• Roof opening panel air deflector assembly
• Roof opening panel seal
• Roof opening panel shield

• Battery junction box (BJB) fuse
• Circuitry
• Accessory delay relay
• Roof opening panel switch

• The roof opening panel does not open or close

• Roof opening panel adjustment.
• Battery junction box (BJB) fuse.
• Circuitry.
• Roof opening panel switch.
• Roof opening panel motor assembly.
• Roof opening panel lifter assemblies.

• The roof opening panel does not open or close — one direction only

• Circuitry.
• Roof opening panel switch.
• Roof opening panel motor assembly.

It almost certainly will be the switches unless you have a broken wire in the loom. There is a cheap piece of kit available on the internet called an op-com that will read these cars including the roof, that will give you fault codes and live data to see exactly where the problem lies.

what i would do is call around and ask if they show a town car with a moon roof and that way you can look at it and if it a self serve yard you can take the part out you need and at the same time learn how to repair your.

Open roof latch over windshild.
Raise rear of roof off of hatch
Lift little hatch tabs to access lift mechanism
Release latches on each side with fingers
Lift Hatch with free hand
Let roof fall into storage compartment
Click hatch shut.
Reverse proceedure to put back up.

You will need to access the wiring to the sun roof and check for shorted/damaged wiring that might be rubbing on sheet metal and causing a short circuit, if you find nothing then the sun roof motor may be the culprit.