Cooling Fans Won't Run

[scott_free]

I have a 2002 Montana. Cooling fans won't turn, it is cool enough that if I am moving it will run at the proper temperature. Fuses, all 3 relays are all good the Temperature sensor/ sending unit is ok has approximately the right resistance for the temperature it is at. The sensor is getting 5 volts from the PCM . I can't tell for sure, but the wiring from the fuse box to the PCM appears to be in good shape. The harness has never been disturbed , but does mean a wire isn't broken some where and I just can't see it. I hate wiring issues too. I don't want to spend big dollars on a PCM replacement and re-config. to find out its a wire some where. Any easy tricks of the trade to check continuity? Also the A/C hasn't worked in quite a few years, so I am not sure if the system needs to see pressure when you turn on the A/C or if it just needs to be switched on to get the fans to run. When I turn it to A/C the fans don't run either.
or would it be more advantages to buy a Hayden auxiliary fan control?

 

[old man]

The first thing I would do is run a wire from the batt to the fan motors to see if they are OK.

 

[scott_free]

I guess I forgot to put that in.... I did jump them both and they run fine.

 

[Steelcity]

Similar thread may be some help

http://www.pontiacforum.com/pontiac/showthread.php?t=24586&highlight=big+hank+compressor

Good luck keep us informed

______________________________

 

[scott_free]

Well that just kinda confirms what I suspected yesterday. The PCM is the issue, but what i don't get is the temperature sensor doubles a sending unit for the temperature gauge and it is running a lot hotter then it has ever ran since I have own it, hasn't got close to the red yet. running the heater is enough to bring it back int its normal operating temp. The van has 340,000 kms (210,000 miles) without ever needing head gasket. I attribute that to running synthetic oil since I have owned it with just over 60,000kms. Is it worth spending big dollars on a PCM and have it config'd by the dealer. I'm thinking not do I spend 40 bucks Hayden Auxiliary Fan Control Unit for 1999-2006 Pontiac Montana, comes with the temp probe sending unit relay and manual override switch. We will see how that works.2nd problem is the water pump decide to start leaking today..well at least it is cheap at Rock auto $15+ shipping.

Thanks for the help