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have to keep adding coolant?


wayneard's Avatar
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02-19-04, 09:07 AM   #1  
wayneard
Cooling fan

Have a 97 Pontiac Sunfire. (Small 4-cyl. 2.2 I believe.) Had to keep adding coolant. Several problems were found. Thermostat sticking shut causing overflow from resevoir; had a pressure test and was told I have a head gasket leak; and finally I found that the cooling fan is not working (which probably caused the overheating to start with).

Had the thermostat replaced. Am trying stop leak for the head gasket. Now to the cooling fan. The fan is good. I removed the fan relay and jumpered relay connections. The relay is good. Swapped with heater relay of same type. But where is the signal coming from that is used to energize the relay??


Thanks for any help.

 
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02-19-04, 10:06 AM   #2  
Sorry to everyone who posted in this thread.

Trying to keep things in order I messed up.

I tried to start a new thread when wayneard posted in it with a different vehicle.

Everone elses responses are gone.... I apologise for the mix up.

Btw wayneard welcome to the forum. It's your first post so we realize this is new to you. It's best to use the"Ask a New Question" button instead of adding on to some elses.

 
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02-19-04, 10:31 AM   #3  
whoa!

need to do some sorting here...

the fan relay is controlled by the PCM, when the temperature gets high enough (probably around 230 F) it will ground the relay coil and turn on the fan motor, there should also be a hot wire to the relay coil so check fuses. all this really needs to be verified by a scan tool as their is no relationship with the guage (if you have one)

as far as stop leak...waste of money and time and may well cause additional problems with circulation thru the radiator and heater core...no such thing as mechanic in a can and even if it does stop the leak, you'll never be able to trust it...it could let go at any time and potentially ruin the entire engine

if you are getting compression in the coling system, it's not going to circulate properly anyways...so the other things may not be diagnosable until you have the mechanical problem repaired

 
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02-20-04, 01:23 PM   #4  
wayneard
I did some more checking. The fuse is good. I have 12V at the one side of the coil. I am still a little confused as to what applies the grnd to the other side. Can you expound on what and where the PCM is?

Thanks.

 
Desi501's Avatar
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02-20-04, 03:57 PM   #5  
Originally posted by wayneard
I did some more checking. The fuse is good. I have 12V at the one side of the coil. I am still a little confused as to what applies the grnd to the other side. Can you expound on what and where the PCM is?

Thanks.
A PCM (power control module) is your main computer that controls all of the electronics in the engine. You fan relay should have at least 4 terminals. 2 with power with 1 possibly key on only. 1 goes to the fan and the trigger ground is supplied by the PCM after it reads the temp input or an A/C request. Unplugging the temp sensor tell the PCM to send ground to the relay. You can test the system that way. Don't use a bulb type testlight to check that relay as anything over 300ma will harm the PCM. You have to use a diode type testlight to check anything attached to the PCM.

 
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