View Full Version : Cooling Fan Revisited

03-04-2003, 11:07 PM
I just wanted to confirm some things regarding the the cooling fan.

Was it ever confirmed that wiring the #14 wire to the #17 wire would force the cooling fan to always run on low speed. But would also shut off the low speed fan when the high speed fan kicks in.

I only saw this discussed once back in August and never again.

When U cut the #14 wire U MUST connect the ICRM side of the #14 wire to the #17 wire. This will turn off the low speed fan when the Hi speed fan is activated. If U do not when the high speed fsn is activated the fan will run at a reduced high speed and over heat.

03-05-2003, 02:26 AM
You do need to turn off the low speed fan for the reason listed.

A few years ago there was a discussion I was involved in whether or not the fan was needed at speed (driving down the freeway). Some said yes it is needed, I said it is not. To prove this I installed 2 LED's, one for low speed and one for high speed. And drove around for about a week. In that week the high speed never came on, and the low speed never came on when I was over 30mph (because there was enough cooling air from forward motion, not because it turns off at a certain speed). The high speed is really for emergency use only. The wiring can't handle that much current for extended amounts of time, it draws around 70amps at startup and about 35amps continuos. If the low speed was engaged first the peak number drops to around 42 amps.

There are 2 separate windings in the motor, and if you have the low speed and high speed engaged the motor runs faster than low but not as fast as high and gets pretty hot compared to just high/low. Give it a try, you'll see.


03-05-2003, 04:23 AM
I'm pretty sure high speed runs everytime the A/C is engaged.

David Neibert
03-05-2003, 10:29 AM
Jeff is correct about the fan wiring, but I ran mine that way for over a year without any problems. David Dalke (XR7Dave) has drawn a new wiring diagram that shuts off the low speed fan when the high speed one is running (89-93). I never got a chance to test it but it looks like it should work fine. Here it is.



03-05-2003, 01:30 PM
I'm up on much of the manual wiring needs and appreciate that wiring diagram from XR7Dave.

What I'm really curious about is the thought that you can skip the work that Dave diagramed by simply attaching the #14 wire to the #17 one. And thus have a low speed always, and when high speed triggers, low speed would then be disabled.