Quote:
Originally Posted by Yarno
Checked the signal coming from the black wire on the fan with an oscilloscope and found it very eratic. It is showing a square wave PWM signal but it was between 3-5volts while the fan was turning and when it was stoped it was all over the place .44V to 2V.
I also have another spare new fan here that I plugged in and it did the same thing, stops after about 10secs.
Does anybody know where the signal comes from? or have and schematics.
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Pulse signal for the fan comes from the DME. DME only provide a signal when the ac switch is activated and the system is running. If the system is not running due to low refrigerant, the DME does not pulse the fan. Not sure if the DME detects a bad fan if it will turn on the compressor for the ac system to work.