78 Audi 5000 Cruise Control Warning Light Problem

I have a 78 Audi 5000 that I have had for about a month now. On two occasions now (both when it was raining), my Cruise Control warning light has come on. When I turn the vehicle off it stays on and will kill the
battery if I don't disconnect the battery. When the Warning light is on anytime I step on the brakes the warning light turns off, and will do so whether the car is running or not.
I have gone through the owner's manual and understand that the warning light has to do with the throttle linkage being stuck or something to that effect? And have looked for information about this and it would seem that Audi had some problems with this during this era; however, the car isn't sticking at all. The throttle works just fine, and the Cruise Control also works just fine when the light isn't on. I have not had any other problems with it at all.
What could the problem be? And if no ideas, how can I turn the light off without disconnecting my battery? I have to wait til the car dries for it to turn itself off.
Thanks for any help you can offer.
Ash
P.S. Any tips for finding a leak in the power steering system would also be appreciated.
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If it is like the later type 44 system, the cruise is canceled by vacuum release switches on the brake and clutch pedals and also an electrical signal when the brake lights come on.
I would be suspicious of the vacuum switches sticking on the brake and / or clutch pedals. It might be simple where a spray lubricant will free up the plastic bits.
A bit of CRC (tuner cleaner) from your local electrical parts store might help when sprayed in the activation switch on the steering column.
Tony '91 100q 5spd
TurboBanana wrote:

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Ash, That electric system sure is an enigma, isn't it? I'll bet you don't wonder whay Audi switched to a vacuum system mid-1980. If you follow the wiring diagram in the Bentley Manual, you can see the things that the warning light is connected to. In addition to the Ignition Cut Out Relay and the Cruise Control Power Relay, the light will also come on when (I do believe) one of the brake pressure switches on the master cylinder is flaky - check for proper operation of these. The cruise on my '80 seldom worked right from the time my parents had it - it would often lose its set at random times, or the speed would decrease. When I got it, the system was so bad that you could set it and it may work for hours, or it may not work at all....initially....but then, an hour or so after you set it and are cruising along, the accelerator would slam to the floor (loss of speed signal?)....or....the car would buck uncontrollably (Ignition Cut Out Relay or Fuel Pump Relay problem?). Eventually I just stopped using the system altogether. As a stop-gap measure, you could pull the warning light out and remove the bulb. Regarding the leak in the power steering system, you could try one of those "magic" stop leak fluids - as the system uses ATF-type fluid and not the synthetic "Liquid Gold" fluid (aka "Pentosin" or "Goo2000"). If the leak is not stopped by that, look up a rebuilder in your area. Cheers! Steve Sears 1987 Audi 5kTQ - Pneumatic Cruise - working well 1980 Audi 5k - Electric Cruise - not working 1962 and '64 Auto Union DKW Junior deLuxes - Organic Cruise (foot) - works. (SPAM Blocker NOTE: Remove SHOES to reply)

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