AudiQua

My battery had a parasitic drain which turned out to be the central lock pump. The pump doesn't seem to be working and it has a continual buzz coming from a component on the electronic board (looks like a relay). I am looking for another unit but I wanted to ask if there is something else wrong like a relay. How do I test power to the pump?

Any help would be greatly appreciated.

The car is a 1994 Audi 90 Quattro and the pump part number is 4a0 862 257 F.

egp320i

Central locking runs on vacuum, under the rear seat check to see if one of the hoses fell off the T or another connector.
Possible one of the white connectors cracked/broke.

BTDT, it fixed the issue.

AudiQua

Thanks for the reply. Found the unit and it was not producing vacuum and buzzing. A fried of mine happened to have a spare. Plugged in the spare and everything works again. I think the electronics were gone on my original CLS.

Onto the next fix.