Electric fan switch
Thread Starter
1st Gear
Joined: Apr 2009
Posts: 1
Likes: 0
From: Dayton Ohio
Electric fan switch
New guy here I have a 95 corvette that I want to ad a switch so I can turn the fans on while sitting in traffic. Every time I get caught in traffic it seems to heat up of course I turn the ac on but I would like to just ad a switch any help would be great.
Thanks
Jim
Thanks
Jim
Instructor
Joined: Jan 2009
Posts: 129
Likes: 1
From: Tucson AZ
Melting Slicks
Joined: Aug 1999
Posts: 2,240
Likes: 41
From: Baltimore, MD USA
The PCM monitors the voltage at one end of the primary coil of the fan relays. So if you ground the coil to enable the relay to turn on the fan or fans manually, a DTC code will set.
On a 95 Vette DTC code 77 or 78 will set.
On a 93 Vette DTC code 28 will set. I'm not sure what code will set for for a 94.
On a 95 Vette DTC code 77 or 78 will set.
On a 93 Vette DTC code 28 will set. I'm not sure what code will set for for a 94.
Instructor
Joined: Jan 2009
Posts: 129
Likes: 1
From: Tucson AZ
The PCM monitors the voltage at one end of the primary coil of the fan relays. So if you ground the coil to enable the relay to turn on the fan or fans manually, a DTC code will set.
On a 95 Vette DTC code 77 or 78 will set.
On a 93 Vette DTC code 28 will set. I'm not sure what code will set for for a 94.
On a 95 Vette DTC code 77 or 78 will set.
On a 93 Vette DTC code 28 will set. I'm not sure what code will set for for a 94.
Drifting
Joined: May 2006
Posts: 1,428
Likes: 7
From: Chewelah Wa
I have a adjustable switch that I purchased through jc whitney for about 15 bucks....it has a little bulb that sits in the upper radiator hose and a dial to set the temp.....I have my main fan come on at 200
Melting Slicks
Joined: Aug 1999
Posts: 2,240
Likes: 41
From: Baltimore, MD USA
The aftermarket kits to manually control the cooling fans, control the fans by grounding the primary coil of the fan relay just like what the ECM/PCM does.
On the latter model C4's the ECM/PCM monitors the voltage of the primary coil of the fan relays. If a problem does exist, a DTC will set but the Malfunction Indicator/Service Engine Soon light will not be lit.
If you were to pull the ECM/PCM codes you would see the DTC.
Not a big deal. Just something the kit manufacturers should mention.
Le Mans Master
Joined: Jan 2006
Posts: 5,620
Likes: 206
From: Orlando FL
The PCM monitors the voltage at one end of the primary coil of the fan relays. So if you ground the coil to enable the relay to turn on the fan or fans manually, a DTC code will set.
On a 95 Vette DTC code 77 or 78 will set.
On a 93 Vette DTC code 28 will set. I'm not sure what code will set for for a 94.
On a 95 Vette DTC code 77 or 78 will set.
On a 93 Vette DTC code 28 will set. I'm not sure what code will set for for a 94.
Instructor
Joined: Jan 2009
Posts: 129
Likes: 1
From: Tucson AZ
The PCM monitors the voltage at one end of the primary coil of the fan relays. So if you ground the coil to enable the relay to turn on the fan or fans manually, a DTC code will set.
On a 95 Vette DTC code 77 or 78 will set.
On a 93 Vette DTC code 28 will set. I'm not sure what code will set for for a 94.
On a 95 Vette DTC code 77 or 78 will set.
On a 93 Vette DTC code 28 will set. I'm not sure what code will set for for a 94.
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