ChrisLSx

Back Story: 2004 C5. When ever I pushed the memory switch (both Driver 1 and 2 are set to the same locations), the Passenger's mirror would go crazy (starts moving all in/full up) until it reached it's limit of travel and stops. I'd bring the mirror back to where I want it, reset the "memory" and if I push the memory button again (either one), the mirror would go crazy again. It's was like it didn't know where it was/should be.


Solution: Without any other solution available, I decided to clean the linear potentiometers in the mirror (spray with electrical cleaner). When I pulled the glass, I realized neither of the pots had been engaged with the glass (they were just floating). Moment of clarity! The backing of the mirror glass has little "ball sockets" that the pots clip into. These ensure that the pots follow the glass and thereby register the movement/location of the glass. If the pots aren't clipped into the backing of the glass, they just float. I clipped the pots into the glass, reassembled and now it's working as it should.

My discover fits exactly with my experience. Because the pots were not clipped into the glass, they were fully "in" (had been pushed "in" by the glass and they remained "in" when the glass moved). So when I set the memory, the BCM registered the glass as full "in" and "up". But any movement/vibration (ie: opening the door, driving the car, etc.) would cause the pots to move ever so slightly (or perhaps not slightly at all). The BCM would then read that the mirrors were off the memory location. This is why the mirror always reset to full in/up. The BCM would drive the glass to it's in/up limit, thereby pushing the pots full in.

Note for reassembly, ENGAGE THE POTS FIRST! You MUST engage the pots FIRST! If you engage any of the other ball sockets before you engage the pots, you will never get the pots engaged. So do the "inner" pot first, then the "upper" pot, then do the two motor drives and finally the main center "knub".

Hope this helps.

quickblue02

Thanks Camaroguy! Good tip. Can you explain how to get the mirror glass off? Thanks!

ChrisLSx

The attached picture (not mine) is of a driver's side, so passenger's side would be mirrored.


Yellow circles are the motor screws
Green circle is the center glass pivot (what the glass actually mounts to)
Red circles are the potentiometers
Not sure what the orange ovals are for


If you carefully push on the glass, you can feel where the glass is supported. You only ever want to push directly over supported areas (ie: center pivot or motor screws). If you push anywhere else, you will bend the glass and possibly crack it.

To remove the glass, you want to move the glass to it's adjustment limits (one way or another, whatever works best for getting your finger tips behind the glass). Then grasping as close to the supported areas as possible (to avoid bending class), pull. The glass will pop off of the mounts. If the motor screws don't come off with the glass, pull them off (get a pair of pliers and pull them straight out of their holes) and then remount them on the glass backing. This makes reassembly easier.

ChrisLSx

Update: It's been a little over a week now and my mirror is much better behaved. It still occasionally decides to adjust/tip down but no longer self adjusts left/right. I suspect that the up/down potentiometer (the lower red circled in post #3's picture) is flaky. It doesn't move far so the potentiometer probably just has a bad spot. I'll try cleaning it one more time and then consider replacing the motor unit.

quickblue02

Thanks, I am going to have to work on my driver side mirror. It is going full up when I start the car.

mrmagloo

Very timely post - Thanks!

While my issue isn't as drastic, I do notice that the mirror position changes a little bit from where I sent them. Same with the seat fore/aft too, but that's another story.

So, you are saying to spray the potentiometers with contact cleaner where they emerge from the housing?

Also, which parts actually connect to the mirror? Looks like in addition to the green mount, the potentiometers ***** pop into something too? Do you by change have a pic of the back of the mirror? Man, messing with this has me a little nervous after a failed attempt years ago.

ChrisLSx

Yes, spray with contact cleaner (it's the best I know to do since the potentiometers can't be removed from the motor).

Everything connects to the mirror. Those potentiometer ***** MUST pop into their respective ball sockets on the back of the mirror otherwise they won't work (follow the mirror glass) correctly. As I stated in my original post, POP THESE IN FIRST.

I did not take any pictures (I pulled the one I posted off of here). Do a search for C5 Corvette mirror replacement (or motor replacement... something like that) and you will get plenty of pictures.

It's not a hard task, just needs to be done carefully and in the correct order.

mrmagloo

Thank you sir!

ChrisLSx

Well my problem came back. It's clearly the potentiometers are bad and it doesn't look like cleaning them is going to be a long-term solution. Does anyone have a part number for the passenger's side motor unit?

ninety6

FYI, i came up with a permanent solution to disabling "memory mirrors" by disabling power to the motors via switch. turn the switch back on and you have power mirrors. turn it off, they won't move.

https://www.corvetteforum.com/forums...r-modules.html