Hello all. I am new to Audi ownership. I come from a Volkswagen background in which I recently sold my 87 GTI 16V for my new ride.
-------1985 Audi 4000s Quattro (white w/ brown)--

It is great to see the wealth of information here pertaining to the 4000 models. Now to the meat....

I have some issues I would like some advice on...

1. Is it possible to install the multifunction computer in a 4000 not originally equipped with one?

2. My differential lock lights do not work?

3. Seat heaters do not work(think it's the relay)

4. Somewhat poor fuel economy (26 highway passes)

5. ISO of white rear doors, front lower grill, black heated leather seats, and white hood.

Thank you all in advance for your info on these topics. Keep up the sharing of knowledge, tips, and opinions on these great autos.

Dennis
peace in the usa

1) Is it possible? *Anything* is possible. However, this is not easy, as I believe that the harness required for the trip computer was not installed. You would have to either duplicate that, or install it. Not inconsiderable amount of work...

2) Lights that do not light indicate locks that do not lock. I would look for vacuum leaks in the system, especially the vacuum lines to the actuators front (center) and rear.

3) Relay, fuse, or broken traces in the seats themselves.

4) The aforementioned vacuum leaks, check timing, possibly the injector o-rings (they go hard after a number of years and don't seal as well), and the rest of the usual tune-up sort of things.

HTH!