I posted a thread about a year ago about my cooling fans not working.I installed a slp fan switch and have been turning them on with that since.But i just want them to work by themselves.I checked all relays wirng as best i could,when i unplug the cts on the water pump i immediatly get a code and the fans come on,also when i scan for codes the fans come on.I did get a code 15 the other day but would it effectthe car cause the car has been driving fine,i erased the code and it hasnt come back on and the car drives fine...I mean should i try to replace the sensor??I replaced it last year...maybe the pigtail?..I just want this to be fixed once and for all!!!!

 

Anyone?? 13 people looked at this with nothing to say?

 

Mike,
Be patient. I am sure that if someone has the answer they will post.
Sounds like open circuits to me.

 

yeah i know..sorry everyone...I just want this fixed,i dont get whats wrong..all my f-bodys have had a cooling fan issue...hopefully i get it done

 

You could try to use your scan tool to tell you what temp the PCM thinks its at. That would verify that the signal is getting to the PCM. The scanner will also tell you when it is trying to turn the fan on.

 

yea but i have a 93 do they even make a scanner for those?

 

Someone correct me if I'm wrong, but a 92-93 uses the same computer as the 3rd gens. You have a 700r4, not the 4L60E, correct?

You need to get a 12pin ALDL adapter. A lot of people get theirs from moates. Or a dyno shop might be able to help you (or the dealer). That and install TunerPro or whatever software you choose.

The other route is to check the voltages. Verify power to the relay, voltage on the temp sensor (search for temp/voltage), and then the output from the PCM. You can also double check the relay is working by grounding the control wire to the relay. That will verify that everything downstream of the PCM is working.

Hope this gives you something new to try.

 

si if i get that 12 pin adapter what scan tool can i get? I might be wrong but i think i have the 4l60 its the same as the 4l60e just not electronically controled.

 

Tunerpro or tunercat will work. Is the car all stock still?

 

On my '94 the 2nd fan doesn't come on automatically until around 240 degrees (just before the engine overheats). My 1st fan which is supposed to come on sooner is not working. Have you perhaps the same problem as me?
Since my 1st stage fan is not working, when the car is sitting at idle I turn the AC on which turns the fan on - so the engine doesn't overheat.
Since my 2nd stage fan works automatically I know that the sensor and wiring are good, at least to the 2nd stage fan.
Also, sensors can go out-of-cal over time.

Just a few ideas.

 

yes its all stock except for a magnflow exhaust.You might have the same problems as me but mine dont come on at all..If i turn the a/c they dont come on either,but thats prolly cause theres no charge in the system cause of a new compressor being put in.

 

Any regular old OBD-I scanner with a 12 pin cable will work on your car.

Do the fans come on when you jump the DLC to flash the codes on the dash? If not, threre are fan schematics on my Tech Page you can use to troubleshoot. Use the early fans schematic.

 

yes they do come on when i jump the dlc.And when i pull the coolant sensor pigtail it immediatly throws a ses and the fans come on

 

Then, the circuitry to operate your fans is ok. So, what is the scenario that your fans are not coming on?

 

I let it run the other day and it was just about in the red,and they did not come on.Im gonna put a new sensor in tommorow.Since the fans come on when i have a ses does this rule out my pcm is bad? Cause other than that the only thing i can think of is that the computer is not getting a correct reading.If the wiring for the sensor was bad would i get a ses for it?I was thinking of putting a new pigtail in.Maybe the sensor only gives the computer a reading to a certain temp? idk,i dont have a scan tool or the money to just order one.When i went to look at the car when i was buying it the fans did work,but they replaced the ignition module,coil,spark plugs and after that they stopped working,idk if theres anything they couldn've done.And i understand the black wire is connected to the tps and i got no problems there,whats the best way to test the pigtail and the wiring for it?