QuestionI have read your answer to a previous question about fans not running.
I have a 1997 Chrysler Town&Country LXI.
The van has overheated a couple times now.
The radiator fans are not running.
I have check the temp sensor, it reads 23,000 ohms cold and dropped below 1500 ohms when engine warmed up.
There is a relay(I think) on the frame rail below the battery, 4707286-D, 64469, 3066H are the numbers on it.
It has 4 leads, Gray w/ 14v present, Green, LightGreen w/blue stripe, black. With the van warmed up I get no voltage on the other leads, only the gray has 14v, this is with the connector disconnected from the relay.
The fan motors have 2 lead connectors, Green and Black.
I have noticed a small amount of coolant a the base of the water pump, is the pump bad? Could it be causing the overheat problems also?"
Thanks
Tony
AnswerHi Tony,
That solid atate relay was failure-prone in the latter 90's and was the subject of a recall. You might be able to get a free replacement at a dealer if yours wasn't done already. The gray wire is the power supply for the fans, if the relay had responded to the request to close the relay points. The voltage would then have appeared on the dark green wire at the relay. The black wire at the relay and the fans is a chassis ground return path for current to get back to the battery. The signal from the engine controller to close the relay comes on the light green/dark glue wire of the relay from pin 73 of the pcm. You could watch that wire to see what is shows as resistance between it and ground when you first start the vehicle and later when the engine is hot. If that changes, for example to show 0 or a few ohms to ground, and still no fans then the relay is indeed bad.
Asmall abount of coolant 'weep' is normal and probably has nothing to do with the overheat. The absence of fans is the issue.
Roland
