'83 533i electric glitch - please help!

I'm having a very strange problem with my 533i. :(

Sometimes when I start the car, the tachometer, fuel gauge, and temperature guage are flatlined at zero, the power windows won't work, and though the car runs smoothly for a minute or two, it begins vascillating when it warms up, with the engine revving from @ 500rpm - 1500rpm and back about once per second... Once I get moving, you would never know that there was anything strange with the engine, it's smooth and powerful... my gauges just seem to be out, and everything else is fine at cruising speed.

THEN, perhaps I'll hit a bump and suddenly my gauges flip up to where they belong, the windows work again, and everything is groovy... until I stop, and the car invariably stalls (it's a manual).

I looked under the hood and saw that the fan was shutting off and kicking back on in rhythm to the engine revving and cutting, revving and cutting... (the fan never stopped because of the momentum, but it was obviously cutting power and losing speed before speeding back up to normal again)

Any thoughts here would be GREATLY appreciated. My regular mechanic is booked solid for a week, so I have to take it somewhere new, and really want to be armed with some information so I don't get sodomized out there...

Muchas gracias,

Sean :)

You have an intermittent open in the accessories circuit, it's an 8 amp fuse in the forward-most row in the fuse box, don't remember if it's the first or second fuse from the left (driver's side). One of the itmes it powers is the idle control module, which is why the idle fluctuates wildly. With the ignition off, remove the fuse and carefully bend either of the contacts to make a tighter fit, then reinsert fuse. If the problem continues and you're SURE that the fuse is not loose, then you've got a wiring problem to cure, more than likely at the fuse box.
Kent

ps
The radiator fan is not electric, it is powered by the water pump pulley with a viscous clutch.

I had this same problem - the solution was a relay attached to the fuse box - bad contact - everything shut down when I hit a bump. Removed - cleaned and re-installed.