radiator fan

[tool88]

ok here is whats going on my car has been over heating i thought it was the water pump but as it turns out my fan is not kicking on i tested the fan it works.

so i tested my plug running from the ccrm to the fan and i not geting a reading from that so i geussing that it could be the ccrm? what else could it be i checked the sending unit that is under the maf its plugged in but as far as giving it a visual to see if its plugged in im not sure on how to make sure it is working ok.

also for a cheap temporary fix i was thinking about runing a toggel to a relay but what i want to know is how heavy of a relay should i get and what is the pin out on a 95 manual 3 wire plug.

thanks

Ben

 

[SHOZ123]

One way to check is to disconnect the ECT sensor. The PCM will default to having the fan on all the time. Probably the hi speed fan. But on the older SHOs if the low speed fan circuit was bad the hi speed won't come on because of temperature. Only when the AC is on will the hi speed fan come on. This may have changed with the ATX or for the '95 MTX.

 

[tool88]

OK i found it unplugged it my fan works now so what does this mean?

 

[SHOZ123]

That means the high speed fan (probably) and circuit through the CCRM are working. The fan should also come on at idle with the AC on.

Now you need to see why the low speed fan is not. It looks like the MTX 3.0L SHO uses a single two speed fan. This is powered from two relays per speed inside the CCRM.

The low speed power wires to the fan are BR/O. The Low and HI speed fan inputs from the PCM to the CCRM is T/O. The Hi speed fan wire colors are DB.

If you have power on both sets of wires then the windings in the motor are probably bad for that speed.

FWIW the fan circuit is fused at 50A.

 

[Ishodu]

Before you go any farther what are your signs of over heating? Most people think once they see the temp needle go up a bit that its over heating. How far is it going?

 

[tool88]

sorry i wanted to tell you that i replaced the ect and my fan is working just fine now.

steam coming out of my hood is what was telling me it was overheating also before it would creap up to the top and id park it, its only overheated 3 times now but im sure thats tomany.

any way thanks for all who replied

thanks ben

now on to the other problems
:thankyou: :thankyou: :thankyou: :thankyou: :thankyou:

 

[sperold]

I learned more from this thread than from any other source. Everyone eventually has engine fan problems and this covers the first steps in figuring out what is wrong.
Could this be a sticky?
I keep telling myself that I am going to save information, but I seldom do; and when it comes time to find it, I can't remember enough of the title to "find" it.