Update on sunroof problem

[davidb]

I have had no luck fixing my sunroof. I have tried three napa switches and all three burned-out. Switch number three went down screaming right after opening my sunroof in the vent position. Pressed to close and nothing, same as the last two switches. I switched the two yellow wires long enough to close the roof and burn-out that side as well. I now know its not the switch. Or at least I think!! I took extra care wireing the last, making sure no wires were touching anywhere they were not supposed to :banghd: Does anyone know why I am burning out switches and not blowing the fuse? Does anyone know how to test the sunroof motor? I sure could use some advise here. My AC is out and without the sunroof ITs HOT. Thanks,

Dave

 

[Rockledge]

Power Moonroof Operation Description

Dave, I've been following your problem with the Napa switch, but I don't really have any solid ideas regarding what may be causing your problem. The best I can do right now is offer a guess that it's either a short of some sort up by the switch, or possibly the moonroof relay is messed up and is energizing the circuit improperly (stuck on?) or something along those lines.

In any event, in case you missed my post a little while back describing how the SHO moonroof circuit works, I'll set it forth here again, maybe it'll give you or some other people a few ideas and/or something to work with. This is out of my '93-'94 Ford Factory Manual:

Power Moonroof - How The Circuit Works

With the Ignition Switch in ACCY or RUN, voltage is applied to the Moonroof Switch. When the Moonroof Switch is in the OPEN position, voltage is applied to the motor and the Moonroof Relay, causing the Relay to energize. With the Relay energized, the motor will run since the Moonroof Relay contacts close to provide a ground path for the motor through the Moonroof Switch close/tilt up contacts.

Moonroof Relay
The Moonroof Relay's operation is slightly different from most relays in that one set of contacts will change position each time the Relay is energized, but will not change position when the relay is deenergized. The other set of contacts in the Relay operate in the same manner as a normal Relay. The contacts will close when the relay is energized and open once the Relay has deenergized.

Closing/Forward
When the Moonroof Switch is in the CLOSE/TILT UP position, voltage is applied to the motor through the latching contacts in the Moonroof Relay. The motor is grounded through the Moonroof Switch open/tilt down contacts, allowing the motor to run. Voltage is also applied to the Moonroof Relay coil when the Moonroof Switch is in the CLOSE/TILT UP position, but the Relay is not energized until the limit switch contacts move to the ROOF CLOSED position. When the Relay energizes, the latch contacts will open, cutting off power to the motor. This prevents the Moonroof from going into the TILT UP position.

Vent
When the TILT UP position is desired, voltage is applied to the Moonroof Relay coil from the close/tilt up contacts of the Moonroof Switch. The relay will energize since the coil is grounded through the roof closed contact of the limit switch and the open/tilt down contacts of the Moonroof Switch. With the Moonroof Relay energized, the latch contacts close to apply voltage to the motor.

Vent Close
To close the Moonroof from the TILT/UP position, voltage is applied to the motor from the open/tilt down contacts of the Moonroof Switch. The Moonroof Relay will not be energized until the limit switch is in the ROOF CLOSED position. When the Moonroof Relay energizes, the latch contacts will open the motor's ground circuit. This will prevent the Moonroof from opening if the Moonroof Switch is not released.

 

[davidb]

Thank you. Do you know where I can find the relay??

 

[Rockledge]

Behind the top RH side of the instrument panel.

 

[davidb]

How hard is it to access and replace the relay???

 

[davidb]

Sunroof repaired

Found a sunroof switch today in the boneyard. It was in a GL. I got the cover and switch for $15.00 Found a generation 1 SHO in the same boneyard. It still has most of its parts. Anyone close to the waldorf area in maryland? If so the car is at Ransom used auto parts on Rt 301 just north of Waldorf. The yard is down the road about one fourth of a mile from the Brandywine used auto parts boneyard where I found a Gen. 2 SHO

Anyway, the switch works fine. I burned up three after market switches before I found this switch.