waussie

the warning light came on the other day for no reason that i could see. i disconnected the sensor and the light was still on. the engine temp
is normal. the coolant level is ok.
any ideas?

A6Gary

Probable short in circuit.

4Driver4

You need a new tank. Or, as Gary said, you have an open in the circuit.

waussie

thanks fellas.

eR-quattro? (rob)

and please keep in mind that this is drawing on my bmw knowledge and not directly from my C4 by trial and error knowledge... - if you disconect the two wires from the tank, and connect them to one another it should cancel the light. you can do this to make certain that your problem is in the parts that are then missing from the loop, OR to keep yourself from looking at that icon until you get the issue taken care of - others please feel free to correct me if this info. doesn't apply to this model - and of course neither AW, myself, or santa clause are responsible if the car sprouts wings, catches on fire, or runs out of coolant unannounced because you've killed the poor old icon that you would have ignored anyway after having looked at it "false" for 6 months... blah, blah, and as always - good luck. i have an e30 3 series car that's had the coolant level sensor wires twisted together since 1993. no light, no other worries. take care. rob.

dirtyhands

It wouldn't be a short circuit, but rather an open circuit. When the harness from the tank is disconnected, the circuit is open, hence the light coming on. I had the same problem with my '83 BMW 733i, just get a piece of wire and make a jumper across the two terminals on the harness. Light should go out, and if it does the float switch has an open in it and needs to be replaced. Thats all the auto check system for the coolant does, its just a dummy light for people who don't regularly check the fluid levels in this car, no big deal. Hope that helps! ;-)

All Wheel Driver

on my audi 90, my coolant light was blinking for no reason and what finally cured it was bleeding the system.
where the coolant hoses go into the firewall leading to the heater core, there is a bleed screw or you can loosen the hose clamp a little and bleed it that way. (if bleed screw is frozen)

I had replaced the coolant tank and sensor, and tried other things, but it was just air in the system that caused it to blink.
The coolant level sensor is quite sensitive too, so if the level is down just a little, that can trip the light too, especially if you go around a turn.

waussie

bridging the sensor stopped the coolant sensor indicator but the overheat temperature started blinking

A6Gary

sensor, it might be reversed, where the coolant level keeps the switch open until the fluid falls and then closes the switch which trips the light.

eR-quattro? (rob)

i should have known better then to apply bimmer knowledge to an audi - worth a try i guess ;~}. r.