The Mercury is fixed!!!!!!!
It took me about 2 hours and one cut finger to repair it. They were right, it was a real pain in the rear end to work on.
Minimal coolant loss. About 4 oz's. I topped off the system with anti-freeze .
The module was not bad. I did a continuity test of all the contacts and there was no problem. Hmmm?
I had the circuit board / diode out of the plastic housing and plugged it into the wire harness to the fan just to see if it would do anything.
Nothing. Bummer. The diode gets very hot so use caution when handling it.
So I said what the heck and I gave it a gentle tap with a plastic tool and the fan came on. Go figure.
Anyway, I put the circuit board back into the housing and tried it again. Nothing. Bummer again...
I wiggled the wire harness connector and sure enough, the fan started up again. I wiggled the harness again and it stopped. Apparently the whole problem was in the connector from the fan to this module. I reinstalled it into the firewall and tried it again. It worked. I then reinstalled everything else that I had to remove to get to it earlier such as, hoses, wires, vacuum tubes and some kind of emissions module. I tried it again and it still worked. So I topped off the radiator and drove it around the block. No fluid leaks and the fan kept blowing. At one point it stopped for a moment but when I ran the fan speed wheel on the dash up and down, it started right up again and will blow cold air like crazy. I think that if it stops again, I'll just wiggle the connector at the module on the firewall and it should run. Maybe it was dusty?
Anyway, it's working and I saved a ton of $$ by fixing it myself. A dealer quoted $355.00 to replace the module.
I thought it would take a lot longer to do but I guess I was lucky. The hardest part was getting the lower screw back into the module housing at the firewall. That took me about 1/2 hour. I kept dropping it. There's really no room to work. I finally decided to remove the top screw that I had already installed and put this one in first. That way I had more room to move the module around while holding the screw in place.
I hope that this helps someone elsethat might encounter this problem. I could have saved a lot of time and grief if I had wiggled the connector at the module first. Oh Well...
I have digital photos available if anyone needs to see what this repain entails.
Ford has a better idea!!! Yea, right......
Keats - Arizona