Air bag light on my 1999 audi a4 quattro 2.8l. Any suggestions?

You make it sound like it's our fault you can't find it :>D

The start of production of the Audi A4 B5 is 1994. With minor changes, it was produced until 2001. At first, only the sedan version was available, the station wagon (Avant) appeared a year later. This material provides information on relay circuits and fuses Audi A4 b5 1994, 1995, 1996, 1997, 1998, 1999, 2000, with an assignment of their elements and locations.

Can't get much clearer than this. Relay 4 is one plus 'Additional Relays 23 and 24. Plus fuse 23 and 24.

Fuse box diagram Audi A4 B5 and relay with assignment ...

https://fuseandrelay.com > audi > a4-b5

This material provides information on relay circuits and fuses Audi A4 b5 1994, 1995, 1996, 1997, 1998, 1999, 2000, with an assignment of their elements and ...
‎Passenger compartment · ‎Main fuse box · ‎Relay box · ‎Engine compartment

its in your owners manual and on cover of fuse/relay covers https://www.manualslib.com/manual/396576/Audi-A4.html

control module needs to be replaced typical problem with the audi's 1999-2004

141 o2 sensor heater, bank 1, sensor 2

I think that the best windshield wiper for 1999 Audi A4 Quattro is BOSCH AEROTWIN (530 mm) - New type with one single rubber blade!

I have the repair manual for 1999 Audi A4 Quattro. I will send you by e-mail, if you will accept my bid. Dimension is 106 Mb, and it is a "pdf" file format. Give me your e-mail address.

The fuses location for the headlamps on a 1999 Audi 2.8 A4 Quattro are:
F18 (10 A) - RH headlamp - high beam
F19 (10 A) - LH headlamp - high beam
F20 (10 A \ 15A) - RH headlamp - low beam, headlamp adjustment
F21 (10 A \ 15A) - LH headlamp - low beam, headlamp adjustment

For Audi A4 the fuse box is located on the left side of dashboard behind a plastic cover (for left hand steering wheel vehicle). On inner face of the plastic cover you will find the fuse diagram.

I have 1999 Audi A4 2,8 quattro water is permanently leaking from the reservouir(or radiator?) and I have to add it every two weeks. What's the solution?

no. suspend engine with engine brace and lower suspension.

should be located on top of your air intake box