Dreaded A6 (C4) transmission MFS repair
 

I'm facing removal of the 4 speed A/T multifunction switch in an A6 Quattro Avant (C4 platform) year 1997.5. In reverse the backup lights don't turn on (although in reverse the third stop lamp DOES turn on, but only in backward motion with no brake), and the passenger side mirror adjusts when I step on the brake pedal. Other stupid things too. It's like a clown car. Brake pedal switch, ignition switch, and steering column combination switch were replaced already. No help. It's the transmission MFS.

The car is no prize and I'm right in the twilight zone of whether to pursue this or donate the car to charity. It won't pass inspection without the backup lights. I may try to remove and recondition the MFS or even buy one. Best price available on aftermarket replacement is $290.

I have read many threads on this repair. I am looking for procedure advice because I still have questions.

I've had the car up on ramps and I see the MFS connector and harness. The switch itself, I gather, is hidden above left-hand transmission mount as explained in other threads (at any rate I cannot see it yet). The mount fasteners look clean, I think I can turn them without stripping them. If I remove the left-hand mount then I presume I have to support the transmission with a floor jack or a block of wood (yes?)

Will I really be able to see and remove the MFS once I've done that? Will I be able to see the bolts fastening the switch to the case? (By this I mean, do the bolts for the switch point downwards from above, so I'll have to grope for them blindly?)

I've wondered if I can remove the selector lever and its trim from inside the car, and perhaps provide access from above. Does anybody know?

EEEERM...its pretty clear you have a wiring issue. 3rd brake light turns on in reverse only= bad groud. mirror adjusts when pressing brake= bad ground. 1st chase down your grounds and or install new or temporary grounds to test. search for ground issue threads on this car and check the usual suspects. You might could get away with temporarily installing a switch in line with your reverse lights to manually turn them on to pass inpection, but that should be a last resort if you have concluded you have a bad reverse light switch. Dont start cutting and splicing wires and end up setting the thing on fire.