Chrysler Repair: 98 MiniVan Overheats due to no fan activity/ module failure, aluminum heat sink, plymouth grand voyager

Question
Hi Friend,

I have a very similar overheating problem to this question previously posted. http://en.allexperts.com/q/Chrysler-Repair-807/Chrysler-T-C-radiator.htm

I own a Chrysler 98 Plymouth Grand Voyager 3.3L, 89k, original owner. It overheats at idle, "Radiator Fan" not kicking in! I changed the Fan Relay Module and it fixed the problem! The Original Fan Relay Module had one pin that you could visibly see it was burner out. After the summer months it burned out again, same pin! I took it to my local shop which they said that it is bad again. Then 4 months later (now), I'm over heating again, all the same symptoms! I'm about to spend the $40 plus bucks to get a new one, and put it in, but I would like to know what is causing the problem! From the other question I noted questioning the Amperage..... what tools could I use to check the amps. I never changed the actual relay or fan. The fuse never blows. What is causing this to burn out???
Note. This Module is a sealed unit mounted on an aluminum heat sink bracket, about the size of a matchbook located below the battery on the drivers side.

Also I could pay for a Diag for $57.00 at Pep Boys... would this me any results what the problen is originating from?

Thanks,
Ken
Hicksville, NY

Answer
Hi Ken,
It would be useful to check the bearings of the fan motors. Try spinning the blades and observe whether one of them is stiffer than the other. That could cause an excessive current draw on the module. That module was a recognized problem area such that there was a recall in the time period of your van, but presumably the newer modules should handle a normal set of fans' load. The fuse for the fan is 40 amp but I don't have a spec for the module. You would need an ammeter function on a multimeter, jumpered in line on the dark green wire, between the module and each fan at its fan plug to measure the draw of each fan. Be sure to measure when the temp is calling for full speed of the fan. I don't believe a diagnostic readout will tell you anything. Maybe improving the contact between the module and its mounting surface to dissipate heat from the electronics would mitigate the problem, or moving it to a cooler location further from the fan module?
I am curious to know what you find out so I can share the information with others. Thanks,
Roland