How do I replace the alternator on my 1990 Audi 200 Turbo?

1990 Audi V-8 Quattro 3.6L DOHC

Starter, removing and installing
Disconnect battery NEGATIVE cable
Disconnect wiring from battery to starter and starter to alternator (large terminal)
Disconnect terminal 50 (small wire to ignition/starter switch)
Remove starter mounting screws on engine/transmission
NOTE: Remove upper bolt on starter by guiding 10 mm Allen socket with extension and flex fitting through opening on transmission housing over final drive
Remove starter motor assembly
Reverse procedure to install

IF ALTERNATOR AND BATTERY BEEN REPLACED.REPLACE THE BATTERY CABLES AND CHECK ALTERNATOR FUSE AND CHECK ALTERNATOR POWER BATTERY FEED WIRE AND VOLTAGE REGULATOR WIRES FOR DAMAGE.

No, 1999 Audi A4 1.8 Turbo does not have any fuse for the alternator.

If the alternator only puts out current at high rpm, it usually indicates it is about to stop working altogether and should be rebuilt or replaced. It should be creating current at idle speed for you. check to be sure at auto zone, they will test it for you usually free.

Speedometer problem: This is well-documented on V8 and 200 models..Check here for info:
http://millerfactor.blogspot.com/2008/05/1991-audi-200-turbo-quattro-and.html

Dash lights: check the dimmer control knob first, then the bulbs..If not those, then it could be related to the problem above...

Driver's seat warmer; could be broken wires leading to the warmers inside the seat from, or the elements are simply burned out.

Blue smoke is oil related, not head gasket (which would be white)..Most V8's will exhibit a little blue smoke from time-to-time, but if it is excessive then it may be time for vailve seals or piston rings..depends on the mileage.

Just a silly question...how much driving do you do that is at 10mph? Most times this is less than 5%...so if everything else is fine why be concerned? As far as the why of it, you could have a slight vacuum leak or any number of sensors that are very slightly out of range, not enough to cause a problem, but enough to change mileage expectations. The addition of ethanol to our fuel has also impacted fuel mileage...The dirty little secret about any alcohol fuel is that nearly twice the amount of alcohol is necessary in order to produce the same energy output of gasoline...which will definitely lower mileage. Some power can be "recovered" by increasing compression ratios and changing engine timing (advance)...However today's vehicles are calibrated and built to burn gasoline and cannot without, major mods, be made to use anything but. Alternative fueled vehicles make a compromise in these areas but a compromise is just that.

Check the fuel filter, you may have clogged it when you filled the tank.

I agree. Replace the battery first. It's under the back seat, which will lift up after undoing two screws in the front of the bottom of the seat. Remove negative terminal, remove positive terminal, lift old battery out, put in new one, attach positive terminal, attach negative terminal, reinstall seat, and you're done.

If that's not the issue, you may need to replace the alternator.

it is going to be something to do with your compression

Hello, I used to own a 1989 audi 200 turbo. These cars have a rather complicated fuel injection system called constant injection system (CIS 2). They can be difficult for most mechanics to figure out, unless they are already familiar with it. If you do bring it to a mechanic, try to find one that is familiar with these cars. And don't be afraid to get a second opinion. I had one mechanic claim that my car needed several thousand dollars worth of parts, another was able to fix it for under a hundred. The only suggestion I have is that it sounds like it is vacuum related. Good luck!