Okay, 1994 Mark VIII with cooling issues. I've got everything changed out to a new radiator, t-stat, hoses, water pump, and radiator fan. The problem is the fan will not come on. As long as you're traveling so air can pass through the radiator, it stays right where it's supposed to be. Sit intraffic for more than 5 minutes and say goodbye to your coolant, temperature, and, if you don't shut it right down, the engine and your ride home.I know from the EVTM, the computer is supposed to sense tempature and trun on the fan. my question is, what tells the computer what the temp is.I did find reference to the ECT sensor (I assume this is different from the temp gauge sensor?)Is there anything else I should be looking at besides making sure there is power to the fan circuit. I can see there are two senders in the coolant crossover pipe, one on the driver's side and one on the passenger side. I assume the ECT is the one on the passenger side? I don't have any codes on this vehicle just an overheating engine at idle
1994 Cooling fan problem...it don't work
- Thread starter mgawat
- Start date
The dash gauge is on the driver's side, so you are right, the ECU stuff read the passenger side sensor. (Gen IIs have but one sensor).
Are you certain the coolant crossover tube is not full of air? If air blockage is bad enough, the sensor is in the air and really reads the air temp which can be a lot lower then the coolant temp. Even with the fan dead, the car should be able to cool itself at 80 degrees outside for more than five minutes when idle.
Turn you AC to MAX and see if the fan comes on, it should no matter what.
Also CAREFULLY move the fan blades with engine off to see if they move freely. If the fan is dead, the motor may be shot.
And last but not least, just make sure the fan is plugged in! Sometimes its the simple things - it sounds like it all worked before.
Are you certain the coolant crossover tube is not full of air? If air blockage is bad enough, the sensor is in the air and really reads the air temp which can be a lot lower then the coolant temp. Even with the fan dead, the car should be able to cool itself at 80 degrees outside for more than five minutes when idle.
Turn you AC to MAX and see if the fan comes on, it should no matter what.
Also CAREFULLY move the fan blades with engine off to see if they move freely. If the fan is dead, the motor may be shot.
And last but not least, just make sure the fan is plugged in! Sometimes its the simple things - it sounds like it all worked before.
fan problems
fan problems
okay, the fan and radiator I just swapped over from my 1994 so I know it works fine. I did make sure the fan was plugged in and even jumped 12v to it to make sure it turned. I have not tried it with the A/C on to see if it comes on. I suspect either a devective ECT,or a wiring problem (deteriorated conductors...wouldn't be the first one I found)>
fan problems
okay, the fan and radiator I just swapped over from my 1994 so I know it works fine. I did make sure the fan was plugged in and even jumped 12v to it to make sure it turned. I have not tried it with the A/C on to see if it comes on. I suspect either a devective ECT,or a wiring problem (deteriorated conductors...wouldn't be the first one I found)>
LeoC2
Registered
Read this, very sad! http://www.topix.net/content/trb/2337275869424300307820692127172409290399
Dump a Mark VIII because you can't replace the VCRM? Any competent mechanic could replace the module's functions with relays and sensors, not to mention units from a junkyard.
mgawt, check and/or replace the fan's 40A fuse(Note sometimes the fuse may blow but still read voltage but cannot carry current). Also trace and verify the gounds from both the fam and the VCRM. When checking with the AC, the AC cycling switch may be suspect as well.
bye
