e32 Jet Heaters

- R
- Rick
  
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posted
17 years ago

Tue, Jan 9, 2007 11:52 AM

I have a 1994 740iL. Can someone tell me what is the setpoint or what causes the Aux Water Pump, Jet Heaters and Windshield defroster to turn on?

I am blowing fuse 9 and IHKA sends a signal to the water pump relay which controls the water pump, jet heaters and windshield defroster but at what point or temperature does the relay energize?

I have operated the car with the aux water pump disconnected but fuse 9 still blows and I lose the horns. I am suspecting a shorted jet heater. Is there any known ohmic value for these heaters?

- J
- John Burns
  
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posted
17 years ago

Tue, Jan 9, 2007 12:22 PM

I believe the aux water pump is always on (unless the heater is off perhaps). had to replace mine recently (e38 730i v8), not a major job.

The jet heaters on most modern BMWs use a sensor in the brake duct to turn them on, but earlier models had them on all the time! I think the E32 uses the sensor.

- D
- Dan Buchan
  
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posted
17 years ago

Tue, Jan 9, 2007 11:41 PM

I have a 1997 E39 and apparently the washer jets are always on, they use the natural property of increasing resistance with temperature to heat up a to a certain point and stay there. I haven't checked this, I don't even know if they work, but that's what the book said.