vfrv4

RE: 1990 GT

Hello,

Need Some help debugging my power windows and sunroof. Been fine for years, cleaned and lubed as needed, etc.

Saturday: Started car, then put down drivers window, All OK. Drove 1/2 mile to gas station, shutoff Car, put in gas, started up. Attempted to put down passenger window and open sunroof..... NO Go. Tried to put up Drivers window, also No go. Crap !

Checks so Far.
1) Swapped fuse # 31 (old Fuse fuse 30amp, tested ok, but what the hell)
2) Voltmeter at fuse #31. NO action = 1.5 volts. Switch action = 10-10.5 volts. Window Voltage holds at 10v + for couple seconds as if its trying to do the 1 step windows down, then fades to steady 1.5v. Sunroof voltage is momentary.
3) Computer/relays under drivers seat make an audible click with each switch.
4) Absolutely NO jiggle/motor noise from windows or sunroof at all. completely dead.

Am I not getting enough voltage?, Should be a full 12v?? I would think even 10v would jiggle the passenger down ,or at least hear some motor noise...I hear no motor noise at all.
Not sure what next checks should be . Any advice would be welcome.

Again this is on the 1990 GT.

Thanks.,
Doug

Speedtoys

motor connections corroded, bad switches..

vfrv4

RE: Dirty switches/motor conections.
Highly unlikely. This is an award winning car (clean) . NOT something intermitent that has been going on over time. Something catastrophic happened to have all three , both windows/sunroof go dead at once.

Something melted or has broken wire somewhere. JUST trying to figure out what to trace first or how to verify the relays/majic box under the drivers seat actualy work?
Or where else to trace on the CE panel?

thanks.

Mrmerlin

most likely the computer under the seat need to be resoldered it controls the mirrors seats and roof.

vfrv4

Merlin,
Wild *** guessing that is correct, the relays box. Even tho the relays click, not letting voltage thru. Is there a write up you can point me to for testing procedure?

Better yet, a write up "repairing the relays box for dummies "

Even betterest 😎, has a good replacement been found as porsche refuses to believe they installed these boxes? Sigh... love my 928's, but they just kill me sometimes .....

Mrmerlin

remove the seat with the box under it ,
then remove the box,
then take it apart ,
get a good solder tool and resolder the board

vfrv4

Thanks for the tip. Ive been staring at fhe box. ....seat all the way forward and the rear raised up, I think I can remove it without removing the seat,. One less step. If looks like I'm going to mangle some wires, I'll pull the seat.

is there a write up once I'm done, test before reinstall the box?

thanks ,

Mrmerlin

after soldering the boards,
put the box back together,
install it in the car,
connect the wires,
test your work

vfrv4

Go it. Thanks! ☺

buccicone

Woohoo, Doug...........