1994 940 Sunroof Not Working/Blowing Fuses

Post by **mdm+mfm** » 29 Jul 2025, 21:02

Hello,

My friend contacted me with a problem that she’s having with the sunroof on her 940 wagon. She told me that the fuse was totally blown, and then when she re-inserted another one and tried it again, the fuse blew again. Since I do not have a sunroof on my 240, I was wondering if there is someone out there that might be able to give me guidance on helping her figure out the problem, and how to do a step-by-step diagnosis and repair. Any help would be greatly appreciated. Thank you in advance.

Vova585 · Post by **Vova585** » 29 Jul 2025, 21:10

Step 1- find original wiring diagram.
Step 2. Never put fuse of higher amp than should go there.
Step 3- you likely have wire that is shorted to ground, sunroof motor that is defective, or mechanical obstruction of sunroof slides.
Step 4. Can remove the sunroof motor and try to energize it through the switch-blown fuse=replace motor. If motor works great and fuse in intact- likely your issue is not in wires or motor and rather in mechanical obstruction of sunroof slides. Inspect slides and see if anything stuck there(dirt, mice, stone, coin..) inspect of slides are properly aligned and not bent.
Good luck.

Post by **mdm+mfm** » 29 Jul 2025, 22:14

Thank you for that rundown; I greatly appreciate it. That is totally systematic and just what I needed to hear. Once I get to the bottom of it, I will post the results. Again, thank you

Post by **mdm+mfm** » 30 Aug 2025, 13:36

After sometime, I’m finally getting a chance to follow up on my friends sunroof issue, and there’s one more piece that I am hoping will help make the determination of what the problem is here.

When I was able to go over and meet with my friend, I did not realize that, as soon as the ignition switch was powered up, the 30 amp fuse blew immediately; the sunroof switch was not depressed, so it seems like there is something that is shorting before the switch. Does that sound right? Any thoughts?