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#11 |
![]() Join Date: Jan 2006
Location: Decatur, AL
Posts: 1,112
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Didn't see the part where you asked if the a/c has to be in run for the pressure switch to run the fan....yes.
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Corvette95 Registry and Forum (*************) 1989 C4 Conv Wht/Gry Auto Hardtop Top Flight SOLD 1995 C4 Coupe Purple/Blk 6 Speed 1989 C4 Conv Wht/Red Auto SOLD 1996 C4 Conv Black/Tan Auto SOLD 1994 C4 Coupe Wht/Blk SOLD 1995 C4 ZR-1 White/Gry #278 Dual Dunn Head SOLD 1986 C4 Coupe Black/Red 4+3 SOLD 1990 C4 ZR-1 Red/Red #0454 |
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#12 |
![]() Join Date: Mar 2007
Location: Crystal Lake, IL
Posts: 7,194
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this is a stock 92 prom. Yes Tech one flashes 12, car runs, etc
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LGAFF 90 #966-150K miles-sold 92 #234-sold 1987 Callaway TT #17 1991 ZR-1 #1359 |
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#13 |
![]() Join Date: Jan 2006
Location: Decatur, AL
Posts: 1,112
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Other than sticking relay, I think they have power from fusible links at all times even with key off, an aftermarket fan switch, or a fault in ignition switch. Has any wiring work been done under the drivers dash such as Vats bypass, alarm, remote door fob etc?
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Corvette95 Registry and Forum (*************) 1989 C4 Conv Wht/Gry Auto Hardtop Top Flight SOLD 1995 C4 Coupe Purple/Blk 6 Speed 1989 C4 Conv Wht/Red Auto SOLD 1996 C4 Conv Black/Tan Auto SOLD 1994 C4 Coupe Wht/Blk SOLD 1995 C4 ZR-1 White/Gry #278 Dual Dunn Head SOLD 1986 C4 Coupe Black/Red 4+3 SOLD 1990 C4 ZR-1 Red/Red #0454 |
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#14 |
![]() Join Date: Mar 2007
Location: Crystal Lake, IL
Posts: 7,194
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Nope all stock wiring... and its only fan 1
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LGAFF 90 #966-150K miles-sold 92 #234-sold 1987 Callaway TT #17 1991 ZR-1 #1359 |
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#15 |
Join Date: May 2020
Location: Windsor
Posts: 38
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I'm thinking the primary cooling fan is "controlled by the ECM" thru the Green Connector "C6". This provides a (-) signal to th Primary Fan Relay.
If you disconnect the Green Connector and turn the key to "ON", you can verify if the fan is being activated by the ECM or something else. If it runs with the Green Connector removed, it's not the ECM. |
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#16 |
![]() Join Date: Mar 2007
Location: Crystal Lake, IL
Posts: 7,194
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LGAFF 90 #966-150K miles-sold 92 #234-sold 1987 Callaway TT #17 1991 ZR-1 #1359 |
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#17 |
![]() Join Date: Mar 2007
Location: Crystal Lake, IL
Posts: 7,194
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I am able to command the fan off with a Tech 1, which I thought was odd...
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LGAFF 90 #966-150K miles-sold 92 #234-sold 1987 Callaway TT #17 1991 ZR-1 #1359 |
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#18 | |
Join Date: May 2020
Location: Windsor
Posts: 38
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Could it be you have a Code 14, 15, 52 or 62 set? If you have any scan-tool (or any device) connected to the ALDL the fan or fans might come on. If you have a faulty Heater/ AC Controller. One or several of these inputs to the ECM could be providing false information causing the ECM to activate the primary fan relay: AC Request (C2), AC Fan Request (C8), Coolant Temp. Sensor (B9), Engine Oil Temp Sensor (B18), |
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