I decided to drive the car for about 30 minutes today on the highway and back roads. It did get hot but again it looked like the above description. After the drive I pulled into the garage and turned off the engine and let it cool for an hour or so. During that time I picked up a spill-less funnel kit so I could make sure there was no air in the coolant system. I installed the funnel kit and warmed up the engine and did not see too many bubbles purge, I waited for the thermostat to open and cycle coolant, no real change, still not too many bubbles. So I thought I would stop for now and shut down the engine. I turned the ignition key off, but the car continued to run, but the gauges/lights/radio turned off. So I put my foot on the brakes and cycled through the shifter positions to see if that would make it difference and it did not. Not matter what position the ignition was in, it would not shut off the engine. I am now looking into what that could be and I am starting with the ignition switch replacement. I don't have a bezel removal tool so I ordered one and until that arrives I will work on other areas of the car.
Because I have never had a Classic Mercury Cougar continue to run after the ignition switch was turned off, I immediately removed the negative battery cable. After doing a little research about what I did to shut down the engine, it seems that could have caused problems with the alternator and or the voltage regulator. I will not know for certain untill I replace the ignition switch and do some power checks.
Anyways here's a list of things to look into the possible cause of the engine continuing to run with the ignition switch off
- replace ignition switch(top priority because just a day ago the car just completely shut down while driving down the highway)
- replace the starter solenoid( it is brand new, maybe 3 months old) $23
- replace voltage regulator( its over 15 years old...I have never replaced it) $28
- replace alternator( its over 15 years old...I have never replaced it) $46
Electronic voltage regulator...$
