Gm ls3 ecu fan controls?
Thread Starter
Burning Brakes
Joined: Apr 2008
Posts: 825
Likes: 40
From: Glasgow, Scotland
Gm ls3 ecu fan controls?
for the guys that have fitted a ls3 to there c3's, when using the gm ls3 harness and ecu from gm performance parts, you can wire the radiator fans into the harness and the ecu controls them, problem iam getting is the ecu is switching on the fans on 5 secs after starting the engine, even tho the the coolant is still cold, any thoughts for my problem?
cheers
dave
cheers
dave
Safety Car
Joined: Aug 2001
Posts: 4,883
Likes: 11
From: North Easton Mass
Check to make sure that you have the fan relays wired correctly. Also check the temp sensor to make sure you don't have any pinched wires. If those things are OK, I would contact GMPP and ask them about the problem.
Rick B.
Rick B.
Burning Brakes
Joined: Oct 2008
Posts: 1,037
Likes: 14
From: Mobile Alabama
The ECU programing turns on the fans at a set temp. Your temp sensor could be sending a bad number. If it is installed with Teflon tape or some other sealant, it may not be getting the ground it needs from the threads.
Thread Starter
Burning Brakes
Joined: Apr 2008
Posts: 825
Likes: 40
From: Glasgow, Scotland
many thanks
dave
Thread Starter
Burning Brakes
Joined: Apr 2008
Posts: 825
Likes: 40
From: Glasgow, Scotland
cheers
dave
Burning Brakes
Joined: Oct 2008
Posts: 1,037
Likes: 14
From: Mobile Alabama
I find the tape is more of a problem than the paste. Sometimes less is better. Maybe try sealant on the first part of the threads and leave the outside clean where it contacts the outer surface of the head.
Thread Starter
Burning Brakes
Joined: Apr 2008
Posts: 825
Likes: 40
From: Glasgow, Scotland
I checked the the 2 wires going into the temp sensor
the yellow wire is showing 4.9 volts and the tan wire is showing nothing?
is that maybe a bad temp sensor?
is the yellow wire the feed wire form the ecu or ?
any help would be good
cheers
dave
the yellow wire is showing 4.9 volts and the tan wire is showing nothing?
is that maybe a bad temp sensor?
is the yellow wire the feed wire form the ecu or ?
any help would be good
cheers
dave
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Drifting
Joined: Mar 2004
Posts: 1,450
Likes: 40
From: Panama City Beach, Florida
This fan setup, if it's the same as for a 2004 LS1 grounds the fans to come on. A hot wire goes directly to the fans and the relays ground the first fan to come at a certain temp ( i forget the temp ) and then the second one will come on when the temp rises.
I did add an extra set of wires that I could ground in case of emergency.
Hope that helps,
Frank
I did add an extra set of wires that I could ground in case of emergency.
Hope that helps,
Frank
Race Director
Joined: Apr 2007
Posts: 11,152
Likes: 890
From: South Western Ontario
FYI, the ECU uses a 2 wire sensor and does not rely on the block or the sensor shell for the sensor ground.
Burning Brakes
Joined: Oct 2008
Posts: 1,037
Likes: 14
From: Mobile Alabama