So I had my A/C compressor removed a couple years ago because it was making noise, and I prefer the windows down, but ever since then my coolant fans were not operating and she would get pretty hot unless there was airflow. Until a tech I had work on it realized that unplugging one of the radiator temp sensors will cause the fans to run all of the time, however that also tells the engine computer that it is HOT and so the starts turn out to be very rich and she doesn't want to start all of the time due to the extra fuel. He says this is only on startup and I agree since while driving, I don't have any issues.

Is there a solution to this problem besides putting a compressor back on my car? Also, am I doing any damage to the motor with the rich starts or anything else? It does run at quarter temp gauge instead of half gauge now!

Thanks!
Tim

 

I removed my bad AC compressor on my '97 SS and left it off for years, never had a fan issue because of it.

 

I think it tell the computer it it running COLD. That would richen the mixture. As the previous response said, there should be no issues just by removing the a/c. The computer should still control all fan function by temperature. Stock, LT1s run hot. Half gauge is normal.

You should probably post what car your LT1 is in and any mods.

 

Put the A/C compressor back on and make the thing run the way it's supposed too.

 

like said above, a/c compressor shouldn't have any effect on cooling fan operation. I removed my compressor 4 years ago and have never had an issue. there has to be something else going on.

 

Right. Unplugging the water pump temp sensor will force the PCM into open loop and the fans will come on since it has no coolant temp information. Check your fan relays to see if they're still good.

 

Orrrrr no?

 

Ok, thanks guys, will have the relays checked out. My car is a stock '97 Trans Am.

I wouldn't say that half gauge is normal because with the fans on full blast, it never goes past quarter gauge. Which should be the case during normal operation, the fans should run to keep the car as cool as possible, no? When I first bought the car a few years ago it was around quarter gauge and then half after no fans...

Tim

 

Stock fans don't come on until 226° and that is around half gauge. So, that's normal to see it up that high before they come on.

 

Are you the original owner? Another possibility is a previous owner could have put in a 160* stat, but did not program the fans. So during highway driving the temps would be low and city it would rise up around where stock temps would be.

 

yeah I have a 160* thermostat in my car and it never gets above the 1/4 mark on the gauge

 

The relays that need to be checked are in the hood relay box correct?

SH

 

That is correct.

 

here's a diagram for your 97. and a link for a 95, they should be pretty damn close, the 95 image may be a little easier to read.

http://shbox.com/1/fan_schematic_1995.jpg

 

Tested the relays in the fog lamp slot and they are all good, now what?

 

I think a simple fix would be to just wire both fans to come on with ignition which is what is happening now. Screw the PCM and how late it 'decides' to cool itself...

Why are there 3 relays anyway and I'm assuming I can just remove the relays and just short pins 1 and 4 of all 3 slot to get both to come on with igniton? The fusable link only has power with ignition I hope? If not where do I grab this power? Any pitfalls?

I should then be able to plug the sensor back in and be back in business!

 

http://shbox.com/1/fan_sw_diagram1.jpg Make yourself a manual switch, it has 3 relays so it can run high or low through the two fans. No need to grab power any where, I'd rather have a switch than having the fans on high 24/7...or figure out why they are not on. Cooler is not always more efficient, the engine needs temp to make a complete and efficient burn. Are you sure your gauge is accurate, you sure the ECT and Coolant temp sensor jive, there's two sensors, one for the gauge, one for the engine to decide needed fuel. I busted the coolant temp sensor off my 93 blazer without knowing it for a few days and it would have a hell of time starting up, because it was dumping fuel since it though it was 5* out when it was 80*

 

If you bypass all the relays, your fans will run until your battery goes dead. Do a fan switch if you don't like the way the fans work as stock and you don't want to reprogram the PCM.

You need this diagram for a 1997:

http://shbox.com/1/fan_sw_diagram2.jpg

 

Whops, forgot OP has an OBDII car!!

 

Here in South Texas cooler is better!

I was going to mention in my last post that a manual switch is lame when you can just pull power from an ignition switched source. Although it would be nice to have them running slower, how is it the green wire is slower? And where are the wires located at?

With some testing of voltages I see that the fusable link has 12 volts all the time, however the relay for the A/C does not, so I will pull power off that.

It would be nice to figure out what is wrong but I currently don't have a lot of money to throw at it and if the stock settings are putting it up at half gauge I would rather have quarter gauge for a longer life of the engine. I'll let you guys know how it turns out after I wire it up... thanks for your posts...

SH