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Mediablitz
06-08-2006, 07:41 AM
My Auxiliary Fan is not working ('95 525 iT).

I had the evaporator replaced last year to the tune of $1800.00 including a new auxiliary fan. for $400.00. I wanted to put in a used fan but the shop said they couldn't do the job without a new fan. I didn't notice whether it worked or not because I was out of state on a trip but now I'm sure that it doesn't.

Recently I replaced both relays since the old ones were charred but still nothing. What I am not sure of is when this fan is meant to come on. If the A/C is on and the engine is warm, then the fan should be on too, yes?

I have a Bentley's manual but am unclear of the different components that make up the aux fan circuit. The first thing to do, I suppose is to see if can get the fan to run at all with a direct current to the fan and I understand there is a resistor on the front top left of the radiator and also a switch on the top right of the radiator. Two relays and two fuses #29 and #25.

The reason this bothers me is that not only did I pay more money to have this A/C problem fixed than I have ever spent on a car, period but the motor knocks a bit under load with the A/C on.

Thanks for any thoughts,

Javier
06-08-2006, 08:06 AM
from hole corresponding to pin 30 to hole corresponding to pin 87.

Presuming F25 and F29 OK, if both speeds are dead, Fan is out, if only high speed works, the resistor is opened, if both speeds work fine, then radiator temp. switch and/or A/C pressure switch are bad.

Mailed you drawings to help you out.

Javier

euaniebabs
06-08-2006, 08:10 AM
Do as the Bentley manual suggests and jumper the connections in the fan switch plug. One way will run high, the other should run low speed. When I had a problem on my 540 6, it only worked on high not low. This is the first thing to check.

If you have already checked the relays, I would put money on your resistor being blown (it may not have been changed with the fan) - this is used to give the lower speed. This is a 0.5 OHM 80-ish Watt item. You will get it from your local Maplin or Radio Shack equivalent. Definitely not worth more than 8-10 $US.

Change this by removing front grill panels or complete bumper, cutting the wires of the old one and putting new one in place.

Good luck!

Mediablitz
06-08-2006, 08:21 AM
I will try those suggestions,

I'll let you guys know.

Mediablitz
06-08-2006, 08:22 AM
Where is the A/C pressure switch located?


from hole corresponding to pin 30 to hole corresponding to pin 87.

Presuming F25 and F29 OK, if both speeds are dead, Fan is out, if only high speed works, the resistor is opened, if both speeds work fine, then radiator temp. switch and/or A/C pressure switch are bad.

Mailed you drawings to help you out.

Javier

Javier
06-08-2006, 12:58 PM
Javier

joshua43214
06-09-2006, 03:57 AM
Don't forget to check all you fuses. Use a test light on th eback of the fuse with the key on and check all of them, not just the ones that are labeled aux fan.