LT1 Based Engine Tech 1993-1997 LT1/LT4 Engine Related

fans are not coming on

Thread Tools
 
Search this Thread
 
Old 04-06-2007, 11:05 PM
  #1  
Registered User
Thread Starter
 
mano's Avatar
 
Join Date: Mar 2007
Location: Lake Charles
Posts: 23
fans are not coming on

both the cooling fans are not coming on unless the a/c is on. So i change the temp sensor on the water pump and put a new thermostat. I also flush the system. When the car is at idle for a bit it wants to overheat. The relays also checked out to be ok. The car is 1994 camaro z28. Help
mano is offline  
Old 04-07-2007, 09:59 AM
  #2  
Registered User
 
Severous01's Avatar
 
Join Date: Jul 2002
Location: Burlington, NJ
Posts: 1,367
did you reprogram your ecm? or have it reprogrammed? maybe they set the temp higher.

if the fans come on during ac, then that means that the wires, relays and motors are good. the ecm is the only other thing keeping the fans from coming on. the ecm controls the ground to the fans using the temp sensor. so...one of 2 things is left....either you got a bad ecm or you just replaced a bad temp sensor with another bad sensor...or the wire's bad.

did you replace the sensor on the side of the block??? that's the one that controls the fans.
Severous01 is offline  
Old 04-07-2007, 10:38 AM
  #3  
Registered User
 
1FstFormulaV8's Avatar
 
Join Date: Oct 2003
Location: Portsmouth, Ohio
Posts: 447
I had that same problem a few years ago. It was a bad ground in the relay box. It was a simple fix, but a pain to solve.
1FstFormulaV8 is offline  
Old 04-07-2007, 10:50 AM
  #4  
Registered User
 
2000GTP's Avatar
 
Join Date: Mar 2005
Location: Aurora, IL
Posts: 12,312
What temp is it running at? Is it in the red? From the factory, these cars are programmed to run warm.
2000GTP is offline  
Old 04-07-2007, 10:55 AM
  #5  
Registered User
 
shoebox's Avatar
 
Join Date: Dec 1969
Location: Little Rock, AR
Posts: 27,709
Originally Posted by Severous01
...

did you replace the sensor on the side of the block??? that's the one that controls the fans.
No, it is not. He already replaced the correct temp sensor.
shoebox is offline  
Old 04-07-2007, 11:18 AM
  #6  
Registered User
 
Dave89IROC's Avatar
 
Join Date: Aug 2002
Location: Melvindale, MI, US
Posts: 4,677
Originally Posted by shoebox
No, it is not. He already replaced the correct temp sensor.
agreed, the one on the side(its in the head, not the block) is for the gauge only
Dave89IROC is offline  
Old 04-07-2007, 02:52 PM
  #7  
Registered User
Thread Starter
 
mano's Avatar
 
Join Date: Mar 2007
Location: Lake Charles
Posts: 23
no i have not change the temp sensor between the plug on the driver side. I did not think that was connected to the pcm and the temprature gauge is working ok because as soon as i turn the a/c on the temprature goes down. I did purchase new fan relays and will change the temp sensor and see what it does.
mano is offline  
Old 04-07-2007, 05:15 PM
  #8  
Registered User
 
shoebox's Avatar
 
Join Date: Dec 1969
Location: Little Rock, AR
Posts: 27,709
Originally Posted by mano
no i have not change the temp sensor between the plug on the driver side. I did not think that was connected to the pcm and the temprature gauge is working ok because as soon as i turn the a/c on the temprature goes down. I did purchase new fan relays and will change the temp sensor and see what it does.
As we are trying to say... the sensor in the head is not for the PCM. You were given bad info. You don't need to change it.
shoebox is offline  
Old 05-11-2007, 08:53 AM
  #9  
Registered User
 
immortalmack's Avatar
 
Join Date: Feb 2006
Location: detroit
Posts: 39
(THREAD HIJACK) What sensor is that in the head because mine is hanging on the ground?
immortalmack is offline  
Old 05-11-2007, 05:07 PM
  #10  
Registered User
 
shoebox's Avatar
 
Join Date: Dec 1969
Location: Little Rock, AR
Posts: 27,709
Originally Posted by immortalmack
(THREAD HIJACK) What sensor is that in the head because mine is hanging on the ground?
It is the sensor for the temp gauge on the dashboard.
shoebox is offline  
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
linz
3rd Gen / L98 Engine Tech
1
04-07-2015 11:49 AM
jayblev95
Track Kill Stories
3
01-15-2015 07:48 AM
AlaskaZ28
LT1 Based Engine Tech
9
01-01-2015 12:30 PM
Red97LT1
Suspension, Chassis, and Brakes
9
12-17-2014 06:13 PM
thenewkid
New Member Introduction
5
11-27-2014 09:41 AM



Quick Reply: fans are not coming on



All times are GMT -5. The time now is 04:12 PM.