I'm having a problem with the fan on my '98 Mustang. It seems to just quit running. When I turn on the A/C, it usually won't run unless I'm going at least 30MPH or so (it gets warm again at every stop light). This isn't always the case, but about 85% of the time it is. Also, if I'm driving around, the car will overheat if I'm in heavy traffic b/c the fan won't kick on (it won't overheat if I'm maintaining a decent constant speed; I'm guessing b/c of air coming in the front of the car whilst it's moving). Any thoughts on this? I've heard some things about the fan relay going bad, or the thermoswitch.
My first instinct was to just wire a standard automotic relay (activated by the ignition) to the fan and just have it turn on when the ignition is on. I know the pros to this is that the fan will stay on if the car is on, but what problems might I encounter if I wired it up this way?
Thanks.