Wing mirror fuse keeps blowing

[pahding]

Hi all, I picked up a 2003 E85 back in April and just got around to dealing with some of the quibbles. One of the issues it had from the jump was with the mirror tilt: it wouldn't adjust right or down, only left and up.

I thought it might be switch issue, so I ordered another used switch assembly and replaced. That then caused the mirror adjustment to stop functioning altogether. Inspection of the fuse box revealed a blown 5A fuse on F8. Replaced with a new fuse, adjustment worked for 2 seconds before blowing again.

I removed the mirrors to take a gander at the assembly, and it seems dusty but in generally good nick. Only thing I can figure now is it might be a short somewhere along in the wiring, but I have no idea where to even begin tackling that. Any help or tips appreciated!

 

[Usel]

So does the passenger mirror work?

 

[pahding]

So does the passenger mirror work?

Both sides had the same issue with the right and down and then obviously both failed to work once the fuse blew.

 

[Usel]

I would say you have a short from the fuse box to the window switch.

Both mirrors are wired independently from the window switch and the only similar part they share is the window switch. However you have changed that and it's unlikely you have bought a new window switch with the same fault.

You could try unplugging the drivers door mirror from the drivers window just to see if this enables you to operate passenger door mirror but you'll likely still have the same problem.

 

[Usel]

I hope you have a multimeter and know how to select the option for continuity so we can test the wiring.

This is connector x887 and plugs into the drivers window switch. Unplug it from the window switch.



Lift the tab on the side and slide the connector out:



The green and blue wire in pin 7 is the 5 amp live from the fuse box. On the other side is the brown wire, pin no. 16:



Use the multimeter in continuity and connect the probes to pin 7 and 16 to see if there is a circuit. Don't worry about the fuse being blown, that's not a problem for now.

 

[pahding]

Thanks for the clear instructions, Usel. Working on getting a multimeter, will report back when I get a chance to test.

 

[Usel]

Been thinking about this and not totally convinced it's a break in the wiring to the window switch.

I'm thinking it's more the mirrors or the window switch (even though you have replaced it.)

Test the window switch with no mirrors connected and then one at a time.

 

[MikeyH]

I spilt coffee on mine and it stopped working properly so after advice on here I took it apart and cleaned it up. It’s been fine since, could this be the cause?

 

[pahding]

Alright all, I'm back to report that I've resolved the issue.

1) The door switch was indeed faulty with half the adjustments out of commission.
2) Fuse 8 (mirror adjustment) kept blowing because Fuse 41 (window lift motor) was missing. I didn't see it on the first go as it's higher up and more tucked away. Why the previous owner just left that fuse blank is beyond me.

Since replacing both with 5A fuses and the door switch panel, the mirror adjustments have been working a charm.

Thanks all for your input, glad I was able to sort out this little quibble.