93 Cooling fan question
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From: Hinesville Georgia
93 Cooling fan question
I bought this 93 a couple mnths ago and ever since I got it the ASR light has remained on. This morning I was under the hood just peeking around and found a wire going to the cooling fans that is spliced into the main harness. Traced the wire back to its orgin and it goes directly into the I/P fuse block and is hooked up there. I am was led to believe thse fans are suppose to come on by themselves, and one only comes on whe the AC is on. Question 1 Is this how they are suppose to work? Once I know for sure how they should work I will try removing the HOT wire and see if the fans come on when they should. I relly do not like the idea of the fans running all the time if I can make them work as they should from the factory.
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Joined: Sep 2010
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From: Hampstead NC
I bought this 93 a couple mnths ago and ever since I got it the ASR light has remained on. This morning I was under the hood just peeking around and found a wire going to the cooling fans that is spliced into the main harness. Traced the wire back to its orgin and it goes directly into the I/P fuse block and is hooked up there. I am was led to believe thse fans are suppose to come on by themselves, and one only comes on whe the AC is on. Question 1 Is this how they are suppose to work? Once I know for sure how they should work I will try removing the HOT wire and see if the fans come on when they should. I relly do not like the idea of the fans running all the time if I can make them work as they should from the factory.
You might want to check it to see if it has been correctly installed before you order a new one. Also, you can check the operation of the TPS with a digital voltmeter (insert a thin hat pin into the back of the connector block and then see if you get a reading that varies as the throttle is moved ... the FSM gives the specs and the wire colors)
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Instructor
Joined: Oct 2011
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From: Hinesville Georgia
Thanks for the response. Right now I am more concerned with the hotwiring of both fans. I am hoping someone can tell me for sure if they are caused to run due to temp or the AC being turned on. If those are true statements then I will unhook the hot wire and watch to see if they actually work like they were designed to work. I dont want them hot wired and running all the time.
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From: SANTA CRUZ CA
fsns
The info in this link may help you understand your cooling system, and fan operation: http://www.theherd.com/articles/lt1_cool.html
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Instructor
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From: Hinesville Georgia
OK, I just read your posted article and I red that the fans should come on at 226F and the secondary shouldcome on at 235F.
I was told the secondary will only come on when the AC sysstem is running. Is there any truth to this? Is so then I am going to unhook the hotwire job and see if my fans come on at all like they are suppose to. I just wnat to be positive that this is how these systems are controlled by the ECM.
I was told the secondary will only come on when the AC sysstem is running. Is there any truth to this? Is so then I am going to unhook the hotwire job and see if my fans come on at all like they are suppose to. I just wnat to be positive that this is how these systems are controlled by the ECM.
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Joined: Oct 2011
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From: Hinesville Georgia
I went and gave it the old shade tree try. The hot wire for the fan was hooked itno ENG1 fuse, pulled the fuse and it was blown. Replace the fuse and unhooked the hotwrie to the fans. Started Vet and the ASR light is now off. Let vet run until the temp gauge got to the center tick mark. NO fan came on at all. I turned on the AC and thee secondary fan started running. So next question.... Is there any test that can be done on the primary relay to see if it is bad? Or do I just buy a new one and pray that was the problem?
I am reaching way down deep to get this vert back on the road.
Thanks for all the help so far.
I am reaching way down deep to get this vert back on the road.
Thanks for all the help so far.
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Joined: Aug 2002
Posts: 3,842
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From: SANTA CRUZ CA
fans
from another forum:
" Your Corvette’s main cooling fan is controlled by the PCM. The PCM sends a ground signal to the fan relay when it sees the desired temperature to run the fan has been met. You need to check the relay and make sure you are getting your battery 12V and ignition 12V when the key is on. With the key on, jump the ground wire in the relay. If the fan turns on, you have an issue in the PCM and it may be time for a rebuild. If it does not turn on, then your problem lies in the fan circuit between the relay and the fans."
" Your Corvette’s main cooling fan is controlled by the PCM. The PCM sends a ground signal to the fan relay when it sees the desired temperature to run the fan has been met. You need to check the relay and make sure you are getting your battery 12V and ignition 12V when the key is on. With the key on, jump the ground wire in the relay. If the fan turns on, you have an issue in the PCM and it may be time for a rebuild. If it does not turn on, then your problem lies in the fan circuit between the relay and the fans."
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Instructor
Joined: Oct 2011
Posts: 123
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From: Hinesville Georgia
Started the car yesterday and watched the temp gauge and fans. Temp gauge got to the center tick mark and no fans, waited a little longer and thought she may be getting a little hot. Was getting reaady to turn the vet off, turned on the AC and secondary fan came on followed by the primary. So ASR light and cooling system corrected. Thanks for the help on these. Now SYS is flashing in the dash. I read that if I ground the "G" of the Data Link Connector, turn on the IGNthat the CCM will display the DTC's. Does that sound like my next step to identify this new problem?
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