Hi, I have an 86 5000CS quattro and have a problem where the dash lights turn off randomly, they may run for 30 secs or 5 mins but then they just turn off. Sometimes if you turn the headlights off and on then the dash lights come back on but not for long. We have tried removing each fuse one by one to try and isolate the problem but no matter which fuse we remove the lights stay on. We have also replaced the switches and the intrument cluster from a parts car to no avail. I saw a post woth a similar problem where it was suggested that the ignition switch may be faulty, is this a possibility?? Can ayone help with this??

Also, there is a major squesk coming from the air conditioning compressor area, we sprayed the belt which would usually change the pitch of the squeal but it hasn't. I'm thinking that the noise may be coming from the compressor istelf or will a simple belt change fix this?? And where is the valve for recharging the AC??

Any help with this stuff would be much appreciated!!!!

Thanks

 

there are a bunch of relays undes the dash Driver side near steerin wheel .... check the connections and check the relays themselves .... tere are more than those behind the "easy " acess cover


recharging valve sould be real close to the AC compressor a few inches from it .... the belt is cheap to replace and takes 10 mins to do .... chande it and it will answer your Q

 

i had that same problem but before i could fix it my clutch went out and i dont have the money to fix it so if u need a parts car hit me up usmcrob6@hotmail.com

 

I have owned a couple of these cars and have encountered this problem before. There is a relay that controls the dash lights and it is mounted above the glove compartment. It is necessary to remove the glove compartment door and liner in order to access it.

The relay adjusts the brightness of the dash lights according to vehicle speed. I know it sounds crazy, but you can look it up in the Bentley service manual. Please remember that these cars are designed and built by Germans, and they manage to think of things that most other ethnic groups would never notice.

In any event, after you remove the glove compartment, you'll find the relay mounted under the underside of the dash. As i recall, it's tucked up where you almost can't see it. It is black, about 2 inches square by 1 inch thick, and has a VDO manufacturer's sticker on it. It will have approximately 4 wires leading to it, one of which is power from the light switch, and one that goes back to the instrument cluster. There's at least one that I think is a signal from the speedometer, and maybe one that is a ground.

There's another relay in the general area: the autocheck control unit. It's mounted in a fairly elaborate bracket, and has quite a few wires running to it. You'll figure it out.

Make a 3 inch jumper wire with a flat spade terminal on each end, and plug it into one of the thicker wires in the socket. Then, turn the light switch on. From there, you'll have to do the old trial-and-error thing. Please though, only touch the other terminals momentarily, so that you don't damage anything. It helps to do this at dusk, so that you can tell if the dash lights come on. Once you have found the correct terminal, plug it in for good and wrap the whole thing up with some elec tape and reassemble the glove box.

Throw the relay away. Your lights will work perfectly, and you'll never have known that they were originally self-dimming.

The last that I knew, and this was about 5 years ago, was that the relay was in the $ 200.00 range. Those funny Germans!

Please let me know if this helps.

 

it works for the moment, thanks very much for the help. Sorry about the slow reply got married and haven't had much time for cars