The air-conditioner compressor in my 1989 Audi 90 front wheel drive will not kick on. I couldn't find a bad fuse or relay. Any suggestions? Thanks...

 

check if the system is charged.

 

Is there a way to "jumper" it to make sure that the compressor is in working condition? The system definitely isn't charged but I don't want to charge it if the compressor is bad. Thanks, Mike

 

hmm
there is only to actually aply power to the clutch, but if there is no oil in it, then you might see a hole new compresor.

it is easyer to just charge it for like 50 buks your self. Use 8oz of PAG46 thats 4 bottles, and a bottle of R134.

Even though your system is R12, you be fine with 134, you will lose efficiency to like 85%. how ever there is diferent gasses that will be higher efficiency, which I have no idea.

each bottle is about 7-8 buks at auto zone, also you will need a charger hose. you might needed a retrofit adapter for like 5 buks.

the easiest way to check for gass in the system is to simply check the valve at the high end, if you press it and gass starts to pure out then there is some or lots.

 

No !!

Don't even try to put R134A in it. R134 works on synthetic oil and your AC works on mineral oil

If you use R134A you will destroy your compressor

If you dont have R12 try to find R22 or R413A

 

Look on eBay, last time I checked old sealed bottles where not that expensive, certainly less than what the dealer will charge you per pound. I don't think that R22 or R413 is compatible with automotive systems.

 

R12 and R134 are NOT compatable. How EVER.
the R12 system (empty) can be charged with R134 gas, The system would lose maximum of 20% of eficiency.
there is the gas similar to PAG but oposite, something with E, that works with miniral oils. check it out.