Charging System Troubleshooting--Blown Ignition Light Fuse?

[ACHiPo]

Originally Posted by patrickt

I can not think of a reason why turning the ignition switch on would turn the fans on. The fan relay on the firewall has a positive feed that is always hot. The negative feed to the relay goes through 1) a thermostatic switch in the radiator hose; and 2) a manual switch on the dash. The negative feed for the fans themselves comes off the X-member at the front of the car.

Put everything back as per the previous post, then gently wiggle things under the dash -- see what happens. Then turn the key on, gently wiggle things under the dash -- see what happens.

Just to check -- this car was wired by the boys at ERA and has not been touched by anyone else, correct?

I’m the only person other than Doug, Bob, and Dan that has touched the wiring.

The fan coming on doesn’t make sense to me, either. I have a couple thoughts: 1) I wiggled something that shorted the temperature sensor to the ignition circuit so when the key is on it tells the fan to turn on, or 2) it has something to do with my initial observation that when I unplugged the fan and the car hit temperature, the ammeter went positive. (Something that makes no sense to Bob or me, thus I doubt my observation of it and want to duplicate it). I tried duplicating this, but discovered the manual fan switch was broken (the switch is removed from the dash and hanging by its wires). As I type this I’m thinking I need to remove the switch completely and tape the lugs—as I recall the manual switch does not turn on the fan with the key off. There might be something conductive in the open manual switch that is turning on the fan.

On another note, I now have several cases that suggest I need to have fuse 3 intact to charge, even with Bob’s configuration. Why would that be? If that is the case, I need to fix the cause of fuse 3 shorting to solve my charging issue. Think I will give my short detector a shot.