Stupid Fan Problems

[BlackStang95]

Hi Guys,

I am having issues with my fan. I have taken my car into Ford previously to get the breaker installed.

I was driving home yesterday and noticed that my car was running hot. Popped the hood, turned on the A/C to Max and the fan did not turn on.

I just took off the breaker and plugged the fan in. I started the car and turned on the A/C to Max and voila! the fan turned on. However, is the fan supposed to stay on all the time if the A/C is on, or is it intermittent? I noticed that my fan turns on and off while the A/C is on and was wondering if that is normal.

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Well...I checked out my friends stang and his fan stays on all the time while the A/C is on Max. Any ideas as to what would cause my fan to turn on and off? Wondering if the fan is semi-seizing? Any ideas?
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Thanks!

Kyle

 

[HISSIN50]

Kyle,
To confirm, high speed is what came on when you removed the CB on the high speed terminal? I wanted to ensure that this was so, and the act of hosing with the actual fan connector didnt have anything to do with it.

As you noted, the fan stays on while the AC is on. There is hysteresis built into the fan switching so that every time the compressor kicks off, it doesnt make the fan go on and off (as yours is doing).

Here are a couple of links with info. On the first, scroll down to second bolded part.

Here's some info about installing manual fan switches if you desire.

Do be careful running without that breaker. It's there to try and keep the fan harness from catching on fire when the fan motor seizes. And our fan motor's do seize.

Good luck.

 

[BlackStang95]

Thanks for the input Hissin50.

Yeah, I'm not planning on running the car without the fan breaker, it was just a test to see if the breaker was bad.

I'd prefer to not put a manual switch in if I don't have to. So where would the fan switching hysteresis be controlled?

Thanks again!

 

[HISSIN50]

Thanks for the input Hissin50.

Yeah, I'm not planning on running the car without the fan breaker, it was just a test to see if the breaker was bad.

I'd prefer to not put a manual switch in if I don't have to. So where would the fan switching hysteresis be controlled?

Thanks again!

Sounds good.

The hysteresis is in the computer programming.

Interestingly, I have a family member with a Probe. The fan acts the same way yours does (bone stock female owned car). I considered rewiring the high speed relay to be controlled by the LPCS input (instead of the output apparently). I never bothered since it didnt't seem to matter.