Originally Posted by
Withakay
2: On my 4th outing and again for only 5 minutes, I stopped and turned off the car,(the AC of course succumbing to its
inexorable demise.) and while conversing with my friend, the engines electric cooling fan, suddenly came on with a
ruckus full speed roar. The car had been off and parked for a good 20 minutes prior to this new development. Ultimately
the only recourse was to disconnect the battery.
I scurried home, turned the car off & on, several times. I even tried
the "disconnected battery cable crossing/cross your heart routine", on the hopes of resetting the computer, but the
obstinate fan prevailed. As soon as you reconnect the battery, the fan takes off "***** to the wall", full bore.
.
Take the cover off the box holding the BCM/ECU/RCM. How bad is it in there? The fan goes "full speed" if it does not hear from the ECU every so many milliseconds, the cause is a bad ECU, a bad Fan Module, or an open data line between the two.
If the fan runs like that with the key OFF, then the ignition lead to the Fan Module is staying energized for some odd reason, OR the Fan Module is bad. Given the rodent damage, there is no way to know without being there and digging into the car. You are not going to fix these issues yourself by posting here and asking questions, this is NOT a typical failure - you are taking on what I think is the biggest challenge with one of these cars there can be!
YOUR ONLY HOPE is to dig into the service manual (and that "STudent Manual" they gave to dealer techs, it's here on the site in the documentation thread) and LEARN how the systems work first. THEN you will have an idea of where to go and what to look at. KEEPING IN MIND that the usual failures/fixes that others have gone thru, do NOT apply to this car. This car did not fail, wear out or suffer the typical "crossfire issues", this car was damaged by rodents and perhaps compromised by sitting outside in the elements for years. There may be corrosion on all the interconnections that run the engine, security systems and climate control -and everything else.
Yea, you have a parts car now, on the OTHER hand, if you ever get this car going, you will have more technical knowledge than 95% of us. Grady in Texas took a car with similar damage and got it running - but he tore the entire car apart to do it. And it took him (I think) over 18 months of weekends to do it. He replaced large parts of the wiring harness, several modules, etc. The guy is amazing.