86 Main cooling fan problem
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Team Owner
Joined: Jan 2003
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From: Summerland B.C. Canada
86 Main cooling fan problem
My main fan had a brain fart yesterday. It was working fine when i left for an hours drive. Out of no where the temp starts climbing so i pull over. The main fan stopped working!! :mad It's sunny and about 95 outside so trying to cool it down is almost hopeless. AC doesn't start fan also.
I didn't get around to much diagnostic work on the fan problem yet because i was to busy removing the leaking power steering rack !! :mad ( leak sealer turned it into a gusher) :mad
After removing rack i remembered that jumping A and B at the Aldl will make the main fan come on. It did come on ( wish i remembered this yesterday) !!
This proves the relay works so is my problem the sensor under throttlebody ?
Or since AC didn't trigger it there could be other problems.
Thanks !!! :cheers:
Also i have a sensor top right of rad (I thought this was my main fan switch)
[Modified by AGENT 86, 10:24 PM 7/21/2003]
I didn't get around to much diagnostic work on the fan problem yet because i was to busy removing the leaking power steering rack !! :mad ( leak sealer turned it into a gusher) :mad
After removing rack i remembered that jumping A and B at the Aldl will make the main fan come on. It did come on ( wish i remembered this yesterday) !!
This proves the relay works so is my problem the sensor under throttlebody ?
Or since AC didn't trigger it there could be other problems.
Thanks !!! :cheers:
Also i have a sensor top right of rad (I thought this was my main fan switch)
[Modified by AGENT 86, 10:24 PM 7/21/2003]
Melting Slicks
Joined: Feb 2003
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From: Saskatoon Sask.
Re: 86 Main cooling fan problem (AGENT 86)
In my line of work, I have found that heat can sometimes do strange things to electrical relays. It is possible that when the relay cooled down, it started working again when you jumpered A and B. I would check all of your connections and then replace the relay. They are cheap($15. our money from Chev). The sensor you refer to is the low coolant sensor.
Thread Starter
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From: Summerland B.C. Canada
Re: 86 Main cooling fan problem (arbee)
Thanks Arbee !!
Another question
Should the main fain come on as soon as i turn on AC or does pressure have to build up before fan is kicked in ?
:cheers:
Another question
Should the main fain come on as soon as i turn on AC or does pressure have to build up before fan is kicked in ?
:cheers:
Melting Slicks
Joined: Feb 2003
Posts: 2,658
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From: Saskatoon Sask.
Re: 86 Main cooling fan problem (AGENT 86)
My understanding is that the A/C kicks the fan in when pressure rises in the high line by a switch over by the evaporator box. This seems to be true as my fan cycles on and off and seems to remain on longer the hotter it is outside.
Thread Starter
Team Owner
Joined: Jan 2003
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From: Summerland B.C. Canada
Re: 86 Main cooling fan problem (arbee)
My understanding is that the A/C kicks the fan in when pressure rises in the high line by a switch over by the evaporator box..
I'll have to check it out. Thanks again !! :cheers:
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From: Cincinnati, Oh USA
Re: 86 Main cooling fan problem (AGENT 86)
The main fan is turned on by the ECM. If the coolant sensor (under the MAF) indicates 228 F , the ECM turns on the main fan and turns it off at 211 F. If the a/c pressure switch reaches 240 psi, it opens and ungrounds pin D11 on the ECM and the ECM turns on the main fan. The a/c switch closes at 190 psi or lower amd opens at 240 psi or higher.
If the coolant temp sensor is defective, you should have a stored code 15 (low temperature) and this will not turn on the fan even though your coolant temp is above 228 F.
No error code is provided for the a/c pressure switch, but if you unplug this switch with the ign on, the fan should turn on. If it does not turn on, you have a short to ground on the green/white wire on this switch or a faulty ECM.
The a/c pressure switch is the first switch on the tubing coming out of the evaporator box on the right side, firewall.
[Modified by jfb, 8:47 PM 7/22/2003]
If the coolant temp sensor is defective, you should have a stored code 15 (low temperature) and this will not turn on the fan even though your coolant temp is above 228 F.
No error code is provided for the a/c pressure switch, but if you unplug this switch with the ign on, the fan should turn on. If it does not turn on, you have a short to ground on the green/white wire on this switch or a faulty ECM.
The a/c pressure switch is the first switch on the tubing coming out of the evaporator box on the right side, firewall.
[Modified by jfb, 8:47 PM 7/22/2003]
4th Gear
Joined: May 2012
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Cooloant fan ?
Am I understanding this right. On my 86 Corvette (it came with no owners manuel). The main coolant fan, turns on only after 228 F?
That seems pretty high. I pulled over at 211 F, thinking she was going to overheat.
That seems pretty high. I pulled over at 211 F, thinking she was going to overheat.
Le Mans Master
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From: Australia
This thread is nearly nine YEARS old
READ
http://forums.corvetteforum.com/foru...s-or-more.html
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From: Freedom is never more than one generation away from extinction.
St. Jude '03 thru '24
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From: Anaheim CA
Now THAT was funny. I was reading through the thread and I couldn't believe this was Agent 86 posting. It just didn't sound like the knowledgeable guy I'm used to seeing...
I guess he learned the same way I did -- plenty of problems and lots of investigation (a long and winding path) -- the infamous "school of hard knocks". ;-)
I guess he learned the same way I did -- plenty of problems and lots of investigation (a long and winding path) -- the infamous "school of hard knocks". ;-)
Thread Starter
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From: Summerland B.C. Canada
