tref

I've been having some intermittent problem where the compressor would run more often than it should and once it would not turn off after shutting off the car.
Recently the compressor went dead so I changed it for a good used unit. It would still run more often than it should and sometime it would not turn off after shutting off the car. Monitoring the pressure and temperature with VagCom showed period of time with over 100C and 20bar and that is way too high. I also noticed the compressor relay was "OFF" while the compressor was running toward these excessive readings. To make a (very) long story short, the compressor relay contacts were sometime staying short even when the controller was turning off the coil. I guess the arcing on the contacts eventually wears out the surfaces and partially weld the contacts together. This 20$ relay actually blew up my 800$ compressor (OK I paid 500$ for the used replacement with the valve module). The car has 200,000km and all 4 air bags have been changed between 120000 and 160000km. The other problem I got around 185000km was the pipe between the compressor and valve block develop a leak where it was rubbing on a metal bracket, it had worked it way out of the clip for some reason. I love this suspension but it is high maintenance, DIY is a must (or insane amount of $$ dumped at the dealer).

F.

moto-one

I would think that at almost 200km your getting your moneys worth. Should last another 200k now.

tref

Yes I'm doing OK but not great, 200,000km is 125,000 miles. I think the CPU could have detected the situation where it had the relay OFF and observed the pressure and temperature running away. This combination should be reported as a stuck relay with some DTC.

Reading some post from time to time I can see that others might have the same problem. Preventive maintenance with a new ~20$ relay at 80,000 miles could be a good idea. YMMV !

F.

ColoradoMark

where is the relay? and do you have the part number? TIA

tref

<center><img src="file://C:\R1.jpg"></center><p>the relay is 8D0-951-253-A and it's location is behind the fuse panel and behind the knee panel below the steering wheel.

allroadSST

The last thread sounds exactly like the same problem. I will replace the relay.

Thank You

1FSTWGN

I have a similar problem except I've replaced both the pump and the valve block. Lights on the dash just flash for a while then give up.

There are four relays matching the number you provided. Can you describe or try giving another picture (the other you posted doesn't show up for me).

I have one relay high in the front along with a 15A fuse. Then I have three lower. One is far left, skip a spot, then two more side by side.

Thanks for whatever help can be provided!

BD

tref

I guess the pictures disapears after a period of time. I do not have my ebahn anymore (since laptop died and I did not reinstall). It is the relay that feeds the pump so pull one out when the pump runs and see if it stops, or get the wiring diagram from ebahn.

todd g

my compressor is not coming on, the yellow warning light on the dash blinks when I first start it, then ultimately goes solid. I took the fuse/relay cover off, replaced the 40Amp compressor fuse, but it blows again within less than 5 seconds. should I try replacing the relay next or should I either pull the compressor out or try testing it while mounted by bringing 12 volt power directly to it? if I try doing it while still mounted on the car, what will I need to make the connections? can it be done w/ jumper cables or will I need something smaller? please be detailed in your answer!

could the relay somehow be causing the fuse to blow???

is it a mistake to replace the relay 1st if I've yet to determine if the compressor will worked when hooked up direct to 12volt? ( I don't want to have to buy 2 relays and/or not know that the compressor motor might somehow damage the relay)

if it is the compressor motor, can just the motor part be replaced? as my mechanic rebuilt the compressor portion w/ andy's kit about 6 months ago. fyi, the front air shocks were replaced w/ new Arnott Gen II's about a year ago. the car has 101,000 miles on it. it is a 2003 2.7 Allroad.

PetrolBear

You can change the relay. When one buys a new compressor, several dealers give a guarantee only if the relay is also renewed. However, your comp can go wrong, either (inside, the electric motor can have a partial short!) which can involve consumptions above 400W - fuse...