cooling fans and heater

[fordfool]

ive been having a battle with my heat in a 98 model for 3 years. backflush, backflush, backflush. ok it now seems that when i turn on the heater the cooling fans come on instantly even though i dont believe they are needed yet. so, i unplugged my fans and the heat works just fine. whats up with that?

thanks

[Loekee75]

Originally Posted by fordfool

ive been having a battle with my heat in a 98 model for 3 years. backflush, backflush, backflush. ok it now seems that when i turn on the heater the cooling fans come on instantly even though i dont believe they are needed yet. so, i unplugged my fans and the heat works just fine. whats up with that?

thanks

When you turn the heater on does your a/c compressor switch on? The fans should only turn on if your a/c button is pushed to the "on" position. It's also possible that the coolant temp. sensor is faulty and telling the computer that the coolant is hot, which in turn switches your fans on all the time. I've known 2 other vehicles that this has happened to. First, check that a/c switch on the dash.

[fordfool]

Originally Posted by Loekee75

When you turn the heater on does your a/c compressor switch on? The fans should only turn on if your a/c button is pushed to the "on" position. It's also possible that the coolant temp. sensor is faulty and telling the computer that the coolant is hot, which in turn switches your fans on all the time. I've known 2 other vehicles that this has happened to. First, check that a/c switch on the dash.

thanks for the reply. i dont have an ac button but ill check to see if the ac compressor is on. with the car idling and the fans off, if i turn on the heater the fans come on. if i turn off the heater the fans run for maybe a minute at most and then cut off. and so on.

thanks

[fordfool]

ive replaced both coolant temp sensors and still have the same problem. what else could make the fans cut on when i turn on the heater? they come on if i put it on any setting other than VENT. they dont come on when in VENT.