Cooling fan circuit explanation - GM Forum - Buick, Cadillac, Chev, Olds, GMC & Pontiac chat


1992-1999 Series I L27 (1992-1994 SE,SLE, SSE) & Series II L36 (1995-1999 SE, SSE, SLE) and common problems for the Series I and II L67 (all supercharged models 92-99) Including Olds 88's, Olds LSS's and Buick Lesabres Please use General Chat for non-mechanical issues, and Performance and Brainstorming for improvements.

Reply
 
 
 
Thread Tools Search this Thread
Old 05-02-2009, 03:33 PM   #1
Senior Member
Posts like a 4 Banger
Thread Starter
 
Join Date: Sep 2008
Location: Tampa Florida
Posts: 106
Thanks: 0
Thanked 0 Times in 0 Posts
QuickLTD is on a distinguished road
Question Cooling fan circuit explanation

Okay... As many of you know I am having issues with my 96 SE'* fans not coming on unless the A/C is on. What I am trying to understand is how they operate. I have read numerous posts on cooling fan issues but none seemed to get into how they work.

There are two fans. A large and a small.
1. Do they always come on at the same time?
2. I see in the diagram they are wired to the TPS. Why? Is that a shared ground?
3. What dictates the high and low speed? Climate control position, coolant temperature and vehicle speed?
4. The two resistors on the large fan are to cut the voltage to allow the fans to run on low speed?
5. Would I be correct to assume that everything shown on the diagram is part of the circuit?

Side note: I changed the ECT sensor and both fan relays.

Thanks guys,
Dean

*** Moved from Chat - Kevin ***
Attached Thumbnails
Cooling fan circuit explanation-fan-circuit.jpg  

Last edited by QuickLTD; 05-02-2009 at 03:41 PM.
QuickLTD is offline   Reply With Quote
Old 05-03-2009, 08:42 AM   #2
Senior Member
Posts like a 4 Banger
Thread Starter
 
Join Date: Sep 2008
Location: Tampa Florida
Posts: 106
Thanks: 0
Thanked 0 Times in 0 Posts
QuickLTD is on a distinguished road
Default

Sorry about posting in the wrong area. I thought it was a generalized question affecting more than just 92-99. Actually should this go in electrical?
Dean

Last edited by QuickLTD; 05-03-2009 at 08:45 AM.
QuickLTD is offline   Reply With Quote
Old 05-03-2009, 10:20 AM   #3
Retired Senior Admin

Expert Gearhead
 
Danthurs's Avatar
 
Join Date: May 2006
Location: Sheboygan Wisconsin
Posts: 29,661
Thanks: 0
Thanked 16 Times in 13 Posts
Danthurs is a name known to allDanthurs is a name known to allDanthurs is a name known to allDanthurs is a name known to allDanthurs is a name known to allDanthurs is a name known to all
Default

The fans turn on by the ECT. They will turn on earlier if the AC is on, and will turn off if the car is moving, that'* why the TPS is involved.
Danthurs is offline   Reply With Quote
Old 05-05-2009, 10:44 AM   #4
Senior Member
Posts like a Turbo
 
Join Date: Nov 2008
Location: Tipp City , Ohio
Posts: 246
Thanked 18 Times in 13 Posts
ssei98 will become famous soon enoughssei98 will become famous soon enough
Default

I'm not sure if this will help you or not but, on my 89 Bonneville I had trouble with the cooling fans. They woould not come on at any time. The A/C was not working at the time (low on freon). I took it to my mechanic and he disconnected the wire to the A/c near the evporator and jumped teh plug with a bent paperclip. I didn't ask any more questions, the fan worked fine and I drove it another year or two without A/c and teh paperclip in place.
ssei98 is offline   Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
Newbie needs explanation kcoop99 2000-2005 54 03-25-2007 10:51 AM
Explanation to remove throttle cables Sully1742 1992-1999 2 10-14-2006 08:08 PM
Explanation of Life SSE14U24ME Lounge 2 10-17-2005 08:03 PM
Explanation of my username & bad news about its origin, dbtk2 Lounge 26 06-10-2005 05:02 PM
H.O. explanation? Allmachtige 1992-1999 2 08-26-2003 04:23 AM


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -4. The time now is 11:37 AM.


We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.