A8L Won't Start After Replacing Wiper Motor
 

2004 A8L
Wipers stopped working so I replaced the part from a used car of the same year and model but the car refuses to start now. Not sure what happened as replacing the wiper motor was pretty straightforward.. When I put the key in the ignition the radio comes on and after a few seconds the odometer/mileage lights up but no gauges and no start. Headlights work, tail lights work and come on when brake is pressed, gear won't shift out of park, the steering wheel isn't locked. I've looked thru quite a few forums by googling checked all the fuses I could find not sure whatbelse to look fornor do...? Any help is greatly appreciated, I don't have a vcds but if anyone is near Springfield, MA I can have the car towed to you to check it out and pay of course.

Sorry I don't have an answer, but Interested in the answer for this as I was about to replace the motor and wiper transmission on my 2006.

A VCDS type scan will give you definitive pointers probably.

Among guesses are you discharged battery, blew a key fused or disturbed wiring. Even if some stuff works, battery may be too discharged to start. You usually hear at least some clicking though, and any lights visibly dim. Worth putting a charger on anyway.

Second guess is still a fuse. Remember they are all over the car. Both sides of dash, both sides of trunk. A few more buried under dash. I don't know which ones specifically are engine related.

Finally, realize that the engine computer is in the same area where you worked. Specifically it is on the passenger side, to the side of the centrally placed HVAC filter and air intake. Look carefully at the humongous connector for that and the harness generally leading up to it. If you fooled with that during your work, obviously a strong candidate for the issue.

The battery is new less than 2 months old replaced by the local audi dealership, all lights are pretty strong so I'm thinking the battery is still good but for good measure I'll have it tested.

I did go thru all fuses on both sides of the dash as well as the ones in the trunk but I dont remember seeing any under the hood, I'll have to check again in the morning.

To replace the wiper motor and transmission I didn't need to unplug anything except the wiper motor, the rest was all screws so I'm fairly certain the computer was untouched but again I'll verify that in the morning.

Any other suggestions are more than welcome. And thank you for your input 👍

You know, I have had it where everything seemed to be working fine but the car wouldn't start, and the voltage on the battery was low. It doesn't meant the battery is bad, just that it got drained.

i agree, when the battery is low, it gets to a point where only 1 or two things work, but then after its just completely dead.
but i also agree with the post above about the ECU wiring. but then again, the wiring for the motor and most of the work is on the opposite side. as menbtioned, a VCDS scan would be good. but check battery also its an easy check

Just unplug the wiper motor to see if it works like when it was dead.
Cheers,
Louis