So here it is, after I fnally wire-up a T/A fog light switch as a Manual Fan Switch. I have just gone through my second relay now. The relay and harness connector both had a burnt spot where the (black w/red stripe) lead is.

The black/red power lead (from relay) runs to the fan. I have spliced it to connect to the indicator light of the fog light (manual fan) switch.
The power to the switch comes from the green (ground) wire from the relay. I am thinking that these two connections are most likely normally linked, so that is why the relay is dying out.

Recently in stop and go city traffic, my fan did not come on since the relay was fried, so I snipped and sealed off the fan wires (coming from the relay) and ran direct current from the battery and chassis ground until i got home. (Incidentally, the battery died that night after I unhooked fan?)

I have been trying to see what can be done to fix this problem. I kept the 12v+ coming straight from the battery to the fan motor. I also kept the original fan wires coming from the relay sealed off and tucked away. What I did differently, was to run the ground from the fan to the ground circuit (fan sensor, manual switch).
So what I have now is a fan that I can turn on/off even with the car off.

The problems I am having are:

1) The indicator light only works when key is on. I can live with that but,

2) When I tested to see if the fan sensor was working correctly, the fan turned on at correct temp, but never turned back off. I turned off car and the fan kept running (again okay, but the fan never turned itself back off after temp went back down below 180*) I had to physically unplug the connector from the fan sensor to get fan to shut off. After that, I put it right back on and the fan remained off.

Any ideas as to what is making the fan not turn back off when sensor ground is not at temp to be made?

 

Anyone?

 

bad fan temp switch could be keeping the ground portion of the relay connected allowing the fan to die. also sounds like you have a battery drain issue due to the battery dying off overnight, or is this due to the fan running until the battery died?

 

It's worth testing your idea of the bad thermal switch. I have another thermo switch that I'll try this weekend.

I am thinking that I might have made a mistake in the wiring of the manul switch. I thought that I had everything right, but the black w/red stripe wire connector (A) at the relay, gets a burned spot on it, and the relay fries after a few months of use.


Oh yeah, I have isolated the current draw to the alternator, so I will be rebuilding it shortly. If I unclip the 2-wire connector at the alternator, the draw drops back down.

Here's the diagram:

 

Here's a (pretty rough) mspaint mapping of my fan/switch circuit below.

I am thinking about changing some of the wiring around a bit. I think I may have to do something different with the top center post. I wonder if it should be grounded seperately, or maybe spliced into the green wire?

Any thoughts on this?

 

Well this setup has been working for almost a month now, with no ill effects.

 

Well you wired it up the way every other properly wired relay has been wired, so.. good job?

 

Yeah, but I was talking about the specific wiring on the switch. To me it just doesn't look right. But with the new relay, everything seems fine, so i guess if it isnt broke......