lt1 cooling fan issue
lt1 cooling fan issue here is a thread on another website that details my cooling issue
http://www.fbody.com/cgi-bin/anythin...i?msgid=901352
please help if you can
i have replaced the sensor in the wp and swapped relays i can get the fans to work with the dlc but not driving down the road
http://www.fbody.com/cgi-bin/anythin...i?msgid=901352
please help if you can
i have replaced the sensor in the wp and swapped relays i can get the fans to work with the dlc but not driving down the road
TECH Regular
Joined: Feb 2006
Posts: 470
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From: St. Louis
I had the same problem. Replaced the same sensors checked relays replaced thermostat, checked fans. Ended up putting in a bypass switch to kick the fans on myself. Wasn't until later when I found out what the real problem was. It was the computer. For some reason the computer either forgets or looses the ability to kick on the fans. I ordered a new computer from MadZ for a custom tune. Had no idea I would be fixing a cooling fan problem at the same time. Sure enough when the new computer came I swapped it in and all of a sudden the fans started working like they were supposed to. All I did was swap the computers. Wierd but I haven't had the problem since. Make sure you check everything first, fans relays sensors etc. If everything is checking out you may have the same problem.
i have already checked the fans by taking them out of the car and running them.
i have done a radiator flush and replaced the thermostat and the coolant temp sensor in th wp.
by jumping the pins on the dlc it tells me that the computer has the ability to turn the fans on
i have done a radiator flush and replaced the thermostat and the coolant temp sensor in th wp.
by jumping the pins on the dlc it tells me that the computer has the ability to turn the fans on
I have the same problem at the moment, went through the same stuff as you, replaced the sender, jumped the ALDL, etc, but despite the fan system working, it wouldn't kick in when it should.
I eventually found out why the fans don't kick on, I hooked up Datamaster and logged the temp, the gauge went into the red and the car overheated, but the PCM only saw 180*. So I would go with 'Lethal Z's' therory of the PCM, soon as I find a replacement PCM at the right price i'll be swapping it out.
Sara Lou
I eventually found out why the fans don't kick on, I hooked up Datamaster and logged the temp, the gauge went into the red and the car overheated, but the PCM only saw 180*. So I would go with 'Lethal Z's' therory of the PCM, soon as I find a replacement PCM at the right price i'll be swapping it out.
Sara Lou
well i swapped the relays around again for the second time and now the fans work.
sara try replacing the coolant temp sensor in the head thats the one that the comp sees the temp from.
i will see if I have a spare and I will let you know
sara try replacing the coolant temp sensor in the head thats the one that the comp sees the temp from.
i will see if I have a spare and I will let you know
TECH Regular
Joined: Feb 2006
Posts: 470
Likes: 0
From: St. Louis
Originally Posted by jester1614
well i swapped the relays around again for the second time and now the fans work.
sara try replacing the coolant temp sensor in the head thats the one that the comp sees the temp from.
i will see if I have a spare and I will let you know
sara try replacing the coolant temp sensor in the head thats the one that the comp sees the temp from.
i will see if I have a spare and I will let you know
The sensor in the head is what tells the gauge what the temp is, the one in the water pump is the one that signals the PCM.
I went through all the tests, checked the resistance on the wiring between the sensor and PCM, checked I was getting the correct voltage at the sensor wiring, etc.
I know the sensor sends varying ohms which the PCM translates to a certain temp, but I can't get my meter on the sensor while its hot and running so I need to put a pigtail on it and check the ohms its sending but I don't want to hack up my wiring, so i'm on the lookout for a spare pigtail to use just now.
Sara Lou
I went through all the tests, checked the resistance on the wiring between the sensor and PCM, checked I was getting the correct voltage at the sensor wiring, etc.
I know the sensor sends varying ohms which the PCM translates to a certain temp, but I can't get my meter on the sensor while its hot and running so I need to put a pigtail on it and check the ohms its sending but I don't want to hack up my wiring, so i'm on the lookout for a spare pigtail to use just now.
Sara Lou
