cooling fan does not turn on

oldman · 08-22-2021, 01:04 PM

A while back I had an issue with the fans stuck on high even after the car was off. This was caused by a poor IAT (in the MAS housing on a LT1) connection and the fact the Procharger has the connector slammed hard against the fan shroud (at least on my setup).

Now the car runs and drive normal, temp gauge starts low and rises as normal, A/C works as normal. BUT the fan never comes on, not a problem or even noticeable till you get stuck in Austin traffic. No codes. I check the huge two wire plug and it is tight. I guess I have to see if it has power and fan just when blah, just asking what else I should check.

I'm sure if I let the car idle it would overheat. Hard to believe the fan died at 17K miles, please also refresh my memory, does the fan come on low when the A/C is on? forget now.

Puddin · 08-22-2021, 01:39 PM

Quote:

Originally Posted by oldman

A while back I had an issue with the fans stuck on high even after the car was off. This was caused by a poor IAT (in the MAS housing on a LT1) connection and the fact the Procharger has the connector slammed hard against the fan shroud (at least on my setup).

Now the car runs and drive normal, temp gauge starts low and rises as normal, A/C works as normal. BUT the fan never comes on, not a problem or even noticeable till you get stuck in Austin traffic. No codes. I check the huge two wire plug and it is tight. I guess I have to see if it has power and fan just when blah, just asking what else I should check.

I'm sure if I let the car idle it would overheat. Hard to believe the fan died at 17K miles, please also refresh my memory, does the fan come on low when the A/C is on? forget now.

Just replaced my fan at 16k miles. It would never come on and would cause my ac compressor to try and cycle on. Mine never overheated no matter how long I let it sit and this was in upper 90 degree days. The fan is supposed to come on automatically when the compressor kicks on and then based off engine temp is how fast it spins.

Trochoidal · 08-22-2021, 02:04 PM

I agree when the compressor engages the fan comes on too. But what I’ve noticed is when the temperature for the AC is set cooler, the fan will soon faster. In the same way when the temperature is set warmer the fan slows down.

I’ll have to pay attention to the correlation of ECT and fan speed. It makes sense that plays a role too.

oldman · 08-22-2021, 04:50 PM

So I just have to check power and if it is hot, replace fan. That is a huge fan and motor, ain't gonna be cheap.

Puddin · 08-22-2021, 05:06 PM

Quote:

Originally Posted by oldman

So I just have to check power and if it is hot, replace fan. That is a huge fan and motor, ain't gonna be cheap.

Rockauto was the cheapest but it was still over 300 bucks. I believe you have to have a pwm tester to even check if it has power. Gone are the days of just using a positive and a negative to try and jump it off.

oldman · 08-22-2021, 08:51 PM

looks like 12v on hot, 5 volts on ground and I did not test the small wire in the harness figure it was to 1) verify the fan on or 2) some sort of temp sensor or don't really know

5 volts on the negative says I screwed up on the ground or my son did something cause I noticed he put 6400 mile on over the past 10 months. Car meant to be used anyway.

Any pictures of locations of the ground point would be appreciated.

*radz28* · 08-23-2021, 08:27 AM

Do you know anyone with HPTuners or EFIlive or something? You can activate the fans with that software.

08-22-2021, 01:04 PM	#1
oldman Drives: SS 6 speed of course Join Date: Jan 2016 Location: Hilo, HI Posts: 4,320	cooling fan does not turn on A while back I had an issue with the fans stuck on high even after the car was off. This was caused by a poor IAT (in the MAS housing on a LT1) connection and the fact the Procharger has the connector slammed hard against the fan shroud (at least on my setup). Now the car runs and drive normal, temp gauge starts low and rises as normal, A/C works as normal. BUT the fan never comes on, not a problem or even noticeable till you get stuck in Austin traffic. No codes. I check the huge two wire plug and it is tight. I guess I have to see if it has power and fan just when blah, just asking what else I should check. I'm sure if I let the car idle it would overheat. Hard to believe the fan died at 17K miles, please also refresh my memory, does the fan come on low when the A/C is on? forget now. __________________ Forged short block, large duration sub .600 lift Cam Motion cam, 7200 RPM fuel cut, Pray Ported Heads, 3.85 pulley D1X, stage II intercooler, DSX secondary low side, DSX E85 sensor, Lingenfelter big bore 2.0 pump, ported front cats, 60608 Borla, LT4 injectors, ZL1 1LE driveshaft and Katech ported TB, ported MSD intake, BTR valvetrain, ARP studs, ProFlow valves, PS4 tires.

08-22-2021, 02:04 PM	#3
Trochoidal Drives: 2017 Camaro 2SS A8 Join Date: May 2019 Location: USA Posts: 1,656	I agree when the compressor engages the fan comes on too. But what I’ve noticed is when the temperature for the AC is set cooler, the fan will soon faster. In the same way when the temperature is set warmer the fan slows down. I’ll have to pay attention to the correlation of ECT and fan speed. It makes sense that plays a role too. __________________ Roto-Fab w/sound tube delete, Katech ported TB, Pray IM, Velossa, DD side markers, DSX FF, UPR Catch can, Halo brace, My custom vent gauge pod Originally Posted by arpad_m - “Aww, yet another oil thread with almost the same question in the OP“

08-22-2021, 04:50 PM	#4
oldman Drives: SS 6 speed of course Join Date: Jan 2016 Location: Hilo, HI Posts: 4,320	So I just have to check power and if it is hot, replace fan. That is a huge fan and motor, ain't gonna be cheap. __________________ Forged short block, large duration sub .600 lift Cam Motion cam, 7200 RPM fuel cut, Pray Ported Heads, 3.85 pulley D1X, stage II intercooler, DSX secondary low side, DSX E85 sensor, Lingenfelter big bore 2.0 pump, ported front cats, 60608 Borla, LT4 injectors, ZL1 1LE driveshaft and Katech ported TB, ported MSD intake, BTR valvetrain, ARP studs, ProFlow valves, PS4 tires.

08-22-2021, 08:51 PM	#6
oldman Drives: SS 6 speed of course Join Date: Jan 2016 Location: Hilo, HI Posts: 4,320	looks like 12v on hot, 5 volts on ground and I did not test the small wire in the harness figure it was to 1) verify the fan on or 2) some sort of temp sensor or don't really know 5 volts on the negative says I screwed up on the ground or my son did something cause I noticed he put 6400 mile on over the past 10 months. Car meant to be used anyway. Any pictures of locations of the ground point would be appreciated. __________________ Forged short block, large duration sub .600 lift Cam Motion cam, 7200 RPM fuel cut, Pray Ported Heads, 3.85 pulley D1X, stage II intercooler, DSX secondary low side, DSX E85 sensor, Lingenfelter big bore 2.0 pump, ported front cats, 60608 Borla, LT4 injectors, ZL1 1LE driveshaft and Katech ported TB, ported MSD intake, BTR valvetrain, ARP studs, ProFlow valves, PS4 tires.

08-23-2021, 08:27 AM	#7
radz28 Petro-sexual Drives: Ultra-Grin Join Date: Oct 2006 Location: Crazy Coast Posts: 15,201 View My Garage	Do you know anyone with HPTuners or EFIlive or something? You can activate the fans with that software. __________________ '20 ZL1 Black "Fury" A10, PDR, Exposed CF Extractor Magnuson Magnum DI TVS2650R // RFBG // Soler 103 // TooHighPSI Port Injection // THPSI Billet Lid // FF // Katech Drop-In // PLM Heat Exchanger // ZLE Cradle bushings // BMR Chassis-Suspension Stuff // aFe Bars // Diode Dynamics LEDs // ACS Composites Guards // CF Dash // Aeroforce // tint // other stuffs

User Name		Remember Me?
Password