Fan Question
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Teching In
Joined: Sep 2007
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From: Oak Grove, Mo
Fan Question I have a issue with one fan not coming on. I have a new fan motor, relay and fuse. I have discoved I have power coming out of the fuse block to the relay with a test light. The blue wire from the computer is going to the relay and when I put the test light in the blue wire at the relay the fan kicks on, as soon as I take the test light away the fan stops. These are ls1 fans also. I have been driving this thing for a year with no problems. Jesse at wait4me did my harness rework.
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From: Oak Grove, Mo
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I'll assume this is a Gen III setup. Disconnect the relay and check continuity on the fan trigger wire (whatever color is going back to the PCM, I guess blue in your case) to the PCM Blue connector, position 42. If you have continuity, then either the relay is bad (which I doubt since you said it worked when the test light was hooked up), or the PCM is not telling the fan to come on. If there is no continuity then the wire is broken.
Jon
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Jon
PSI
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Teching In
Joined: Sep 2007
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From: Oak Grove, Mo
I have a new relay, I am going to dig thru the harness and check the blue wire from the pcm to relay. What happends if it's not getting a signal from the pcm? How do I fix this issue?
Which relay terminal is it connected to? Better yet, how are all the wires connected at the relay? We can't really tell you what's wrong without knowing more about the way you have the wires connected.
Ok, this setup worked fine for a year, right? You changed the motor, relay, and fuse because a fan stopped working. One fan still turns on properly, right? And when you change your plugs around, the new fan comes on, right? I'd take a look at the plug on the nonworking fan.
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Joined: Sep 2007
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From: Oak Grove, Mo
I have replaced the connector on the non working fan. I have the blue wire to the relay from the pcm. I have a hot wire to the relay from the fuse block that get its power from the battery. I have checked the wire and it is not broken. Can I take another wire from the pcm or can I control the fans another way?
Joined: Sep 2004
Posts: 3,148
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From: Downers Grove, IL
From some of your other posts it looks like you may be running a truck 5.3L?
1. Is it a truck PCM? What year?
2. Did the fans ever work or has this been a problem from the start?
3. What pcm pin does the blue wire go to? (Most likely blue connector pin 42 or red connector pin 33).
1. Is it a truck PCM? What year?
2. Did the fans ever work or has this been a problem from the start?
3. What pcm pin does the blue wire go to? (Most likely blue connector pin 42 or red connector pin 33).
Thread Starter
Teching In
Joined: Sep 2007
Posts: 47
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From: Oak Grove, Mo
From some of your other posts it looks like you may be running a truck 5.3L?
1. Is it a truck PCM? What year?
2. Did the fans ever work or has this been a problem from the start?
3. What pcm pin does the blue wire go to? (Most likely blue connector pin 42 or red connector pin 33).
1. Is it a truck PCM? What year?
2. Did the fans ever work or has this been a problem from the start?
3. What pcm pin does the blue wire go to? (Most likely blue connector pin 42 or red connector pin 33).
The fans have always worked, I noticed I had a problem when i was blowing a fuse when the fans came on ,So i put two new fan motors and connectors and now only one fan works.
The blue wire goes to pin 42 blue connector.
Joined: Sep 2004
Posts: 3,148
Likes: 12
From: Downers Grove, IL
Try popping the connector off the PCM and ground the blue wire that goes to pin 42 at the pcm connector with the ignition on. If the fans turn on the problem is in the PCM, if they don`t turn on then its in the fan, the connectors or the relay.
