QuestionQUESTION: I have a '97 Cadillac Deville, 8cyl. 4.6L engine. The car keeps having an overheating problem. I replaced the water pump, thermostat, knock sensor, and even the plugs and wires. But it still overheats after about 15 min of driving. The radiator and fan seem to be fine, but the heating and a/c is not blowing anymore. Could the blower motor be causing the problem or is it something else?
ANSWER: What makes you think that it is over heating ?. Normal temp range is 220-230.
As to the AC, the blower motor does not run at all ?.
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QUESTION: The car is telling me itself it is overheating and to shut the engine off (once the temp is passing 275, after about 15 min of driving). As for the blower motor, (the a/c-heater blows no air what-so-ever) I ask if it is related because when flushing the radiator, afer adding new coolant it says to idle the car with the heater running.
AnswerHave the engine tested for blown head gaskets which is very common with Cadillac engines.
As to the blower motor check the RED wire at the blower motor for battery voltage at all times. Check the BLACK wire for a good ground.
Problem is most likely the blower motor itself if the above 2 wires check out OK. However, I have seen some AC/Heater programmers cause a blower motor fault.
I can provide you with pictures and diagnostic test procedures for you to find the exact cause of your blower motor problem by e-mailing me at: onlineautohelp@msn.com.
I would first be concerned about the engine overheating first.
