99' fan

my fan goes off then comes back on frequently, and its driving me nutz, does anyone know if that is howit is supposed to run? if so how can i make it not so loud or annoying, i live in alaska and i was thinking about disconnecting it.

The aux electric comes on for two reasons, engine is hot or you have either the AC or Defrosters going, both use the ac compressor and the fan cycles kinda with it.
My 98 very rarely comes on w/o the compressor thogh it did a few weeks ago when my daughter was practicing parallel parking w/garbage cans in the driveway. I noticed that it came on about every 15 min or so.
If it's coming on w/o the compressor or high temp it might be the temp sensor switch.

At least your freaking fan comes on!

I have the same problem, when my defroster is on my aux fan kicks on and off almost instantly over and over. I agree it is very annoying, it makes my head lights dim everytime. I would love to know how to fix it if there is a way.

The defroster runs the AC compressor, and the fan cycles on and off with the compressor. It is that way by design.

No way to bypass this?

Should be a single wire running to the back of the compressor. Unplugging that should disable the compressor, but you won't have AC or full defrost function.

Others may disagree, but I always disable my AC in cold weather so that I get only hot defrost. Here in Vermont, there are many days when you need defrost or defog, but if you run the ac it chills the windshield so much that you must run it constantly even when it's done, or it will fog right up again. Cool humid weather especially. In the right conditions the cold defrost on the inside causes it to frost up on the outside and then I need the wipers even though it's dry out. Hot defrost doesn't act as quickly but when it's dried the windshield it stays dry much longer.

You can stop the AC by unplugging the pressure switch. Look on the passenger side near the firewall for the piece of AC plumbing that has an electrical connector on it, and just pull that plug.

AKjeeper,

Here's a draft of something I put together about the operation of the 97-99 electric radiator cooling fan. Read through this, it may help you understand how this thing works.

If your A/C refrigerant charge pressure is low your A/C will cycle on and off frequently. You may want to check the system (low side) pressure to see if it's above 34-38 psi.

99blueJP said:

I have the same problem, when my defroster is on my aux fan kicks on and off almost instantly over and over. I agree it is very annoying, it makes my head lights dim everytime. I would love to know how to fix it if there is a way.

Click to expand...

Looks like it is time to get after your power cables. The lights should not dim when the fan runs...