Ok here's the problem, a while back I went out to start my car and it wouldn't start, so I had a family member jumpstart the car, everything seemed fine it was just very odd that my batter was dead for seemingly no reason. A few minutes later when I stopped at a stop sign I noticed that the car was having trouble with staying running so I looked down at the instrument panel and noticed that the battery was draining rapidly, I pretty much had to put the car in park whenever I stopped (stoplight, stop sign). When I got home I went through the fuses and it turned out to be the fan, since then I can go outside and start the car right up as long as the fan stays unhooked but as soon as I hook it up it drains the battery both with the car off and on.

 

I'm unclear on why you think it's the fan? With the engine running your alternator should be supplying all the juice, so the battery is just being charged with any excess juice.

You need to put a voltmeter on the battery with the engine running, it should be 13.8-14.5 volts at idle with no accessories running, including the cooling fan.

 

That's why I'm posting my problem on here because it shouldn't be draining my battery.
The reason that I think it is the fan is because I went through the fuse box to diagnose what was draining the battery with the car off and the fan was the only one pulling electricity, which it shouldn't have because the fan wasn't running and the car hadn't been on in days.
Then when I diagnosed why the battery was being drained with the car on i couldn't find anything so on a hunch i unhooked the fan to see if that's what was causing it and the car ran fine so I hooked the fan back up just to be sure it was the fan and the car barely was able to stay running, i can't even put the car in reverse without the car wanting to quit on me while the fan is hooked up. And I know it's not the alternator because I had that checked and it showed up as being good, plus I can hookup my amp up when the fan is unhooked and the car runs fine, heck i can cut everything on on the car and it runs fine,but if I hook the fan up I have unhook my amp and I can't cut anything on since it wants to quit on me by just putting the car in reverse.

 

Does the fan work when it is supposed to? Like with the A/C on? The fan itself might have failed in a partial shorted condition- not enough to blow the fuse. Or one of the fan relays might have done the same. They are located in the bussed electrical center where the fuses are. The system is controlled by the PCM.

Frank

 

Sounds like the cooling fan circuit has a high impedance short limiting the current, otherwise it would be blowing the fuse.

 

Yes the fan works when it's suppose to. And where would the fan relay be, from what I've read on the 98 mustang it is behind the front passenger side wheel well, is that correct.

 

This is a '98 Mustang? You are posting in the 2005+ area.

Frank