Conversions & Swaps LSX Engines in Non-LSX Vehicles
Sponsored by:
Sponsored by:

Fan relay question...

Thread Tools
 
Search this Thread
 
Old 05-28-2010, 01:37 PM
  #1  
Launching!
Thread Starter
iTrader: (1)
 
Racinjason424's Avatar
 
Join Date: Oct 2008
Location: HOLT, MI
Posts: 242
Likes: 0
Received 0 Likes on 0 Posts
Default Fan relay question...

I've been searching fan relay wiring threads all morning and my eyes are burning! I found a ton of threads for wiring single fans with 1 or 2 relays and dual fans with three relays, which seems to be the original way GM set the things up..

I have a dual fan set up, with which I bought a fan relay wiring kit from the same company and it has 2 relays in the harness... I have a speartech modified wiring harness that has low speed/ high speed wires..

Without adding a 3rd relay, what are my options for function and control without possibly throwing any error codes!? Can I have both fans run only on low? both run only on high? If I can have them both run on low w/o overheating, I would prefer, just so the fans arent screaming on high all the time.. Appreciate any help wiring these guys up!! Thanks - Jason.
Old 05-28-2010, 03:03 PM
  #2  
TECH Resident
 
Andy1's Avatar
 
Join Date: May 2004
Location: SoCal
Posts: 791
Likes: 0
Received 2 Likes on 2 Posts

Default

I can't comment on a dual relay setup, but I wired my fans with the GM 3 relay wiring scheme. It does work great; PCM controlled low speed runs both fans in series (so they run 1/2 speed @ 6V; nice and quiet), and can switch over to high speed and runs both fans in parallel (so they run at full speed; each seeing 12V).

Andys
Old 05-28-2010, 08:02 PM
  #3  
Launching!
Thread Starter
iTrader: (1)
 
Racinjason424's Avatar
 
Join Date: Oct 2008
Location: HOLT, MI
Posts: 242
Likes: 0
Received 0 Likes on 0 Posts
Default

UPDATE: Actually, my speartech modified harness has only one green wire labeled "Primary Fan Relay"..

And my fan wire harness with two relays has two "+positive+" trigger wires that says to hook up to keyed 12v power. There is also two "-negatigve-" trigger wires that say when grounded, will activate the relays. I'm assuming I hook the green CPU wire to the two negative triggers.. Would this operate both fans on low speed or high?
Old 05-28-2010, 08:48 PM
  #4  
TECH Addict
iTrader: (2)
 
crainholio's Avatar
 
Join Date: Aug 2003
Posts: 2,977
Likes: 0
Received 3 Likes on 3 Posts

Default

Originally Posted by Racinjason424
UPDATE: Actually, my speartech modified harness has only one green wire labeled "Primary Fan Relay"..

And my fan wire harness with two relays has two "+positive+" trigger wires that says to hook up to keyed 12v power. There is also two "-negatigve-" trigger wires that say when grounded, will activate the relays. I'm assuming I hook the green CPU wire to the two negative triggers.. Would this operate both fans on low speed or high?
High. The PCM closes both relays the way you're wired, both fans get fed 12VDC and spin to their rated speed.



Quick Reply: Fan relay question...



All times are GMT -5. The time now is 01:41 AM.