jeffrsmith

I have an intermittent problem with my sunroof blowing fuses, but only when it is hot outside. If the car has been parked in the sun and I try to open the sunroof it blows the fuse and all the dash gages go dead.

Initially the sunroof would not work at all, I completed the troubleshooting steps from Clark's and determined that I had a bad ingition switch. I replaced the ignition switch and things appeared to be working as designed. First day I drove the car to work and parked it in the sun, at the end of the day when I tried to open the sunroof it blew fuse 18 killing the gauges on the dash as well.

Drove the car home, replaced the fuse and all worked well again. In an attempt to try to correct this issue I have cleaned two of the grounds under the dash, I still have two more to get to, but does anyone have any thoughts on what would cause a problem such as this?

I did have the engine out of the car last fall to do a major reseal,
When I had the engine out, I cleaned all the grounds in the engine bay.

The sunroof is not the only electrical issue I am experiencing - when the car is hot from sitting in the sun the a/c / heater blower motor will only run in the #4 position (works fine on a cool day). My gas gauge does not work all the time, it only works when the car interior is hot from sitting in the sun. I have had the cluster out and cleaned the ribbon cable connectors and the "football" connector on the back of the gauge with no luck.

Any pointers what/how to troubleshoot these issues would be much appreciated. I followed Clark's troubleshooting for the fuel gauge, the sending unit works as it should. Don't know if the sunroof, blower switch, and the fuel gauge are related.

william_b_noble

check for bad connections in the copper strips in the central electronics, and check that the sunroof isn't binding in the heat

jeffrsmith

When you refer to central electronics, are you referring to the fuse/relay block under the hood?

odurandina

after 30 years, somewhere in this high H20 environment, a wire might be grounding out.

william_b_noble

yes. I try to use the terminology used by the Porsche service material. I don't always succeed, but I try.