Air conditioning problem

[Mikes vette]

I own a 72 vette, 383 stroker, 750hollydp, MSD ignition, mildcam, 400hp.

My problem is I just had Vintage Air conditioning unit installed, the fan runs constantly even when the heater switch is turned off, the a/c is not turned on.

Vintage air said it could be the spark plugs or the MSD ignition wire may not be grounded to the battery.

any suggestions?

thanks, Mike

 

[Rusty_S]

I own a 72 vette, 383 stroker, 750hollydp, MSD ignition, mildcam, 400hp.

My problem is I just had Vintage Air conditioning unit installed, the fan runs constantly even when the heater switch is turned off, the a/c is not turned on.

Vintage air said it could be the spark plugs or the MSD ignition wire may not be grounded to the battery.

any suggestions?

thanks, Mike

Well I have a 1981 Corvette factory a/c and the fan always runs. From my tech classes I took in AC I found out that was designed to do that on these cars to keep air circulating while your driving. Now if this is doing it with the key off I would worry about it.

 

[Mikes vette]

Well I have a 1981 Corvette factory a/c and the fan always runs. From my tech classes I took in AC I found out that was designed to do that on these cars to keep air circulating while your driving. Now if this is doing it with the key off I would worry about it.

So even though the A/C is not on, the the heater is not on, its fine to have the fan running on and off constantly?

And with the key off, you mean of course when the car is not running?

Plus why wouldn't Vintage Air know this?


thanks, Mike

 

[petes74ttop]

Fan Motor

On my 74 with factory air the fan runs all the time except if I move the left thumb wheel to off. PG.

 

[cstarr89]

I also have a stock 81 with a/c and the fan does run constantly. Though I'm not sure why. I thought this was also strange but I guess that's just how they were designed?

 

[Mikes vette]

So this is normal? Wonder why it does this? I can understand if I had the air conditioning was turned on...............then the fan would come on, and circulate the air, but when its not on?

On my 1989 GMC pick-up that has factory air, this does not happen?

thanks guys, will be back tomorrow.

tis now 12;40 am here in Toronto.

Mike.............totally baffled here!

 

[Rusty_S]

I also have a stock 81 with a/c and the fan does run constantly. Though I'm not sure why. I thought this was also strange but I guess that's just how they were designed?

It sounds strange but my 81 corvette does it only when the key is in the On position not the Acc, or Off position. I got it to stop but the fan will never come on though. But my 1979 El Camino does the same fan runs slow constantly with the key in the On position.

For brand new cars that are being made alot of them have sensors that when it reaches say 130 degrees inside a small fan kicks on and pulls fresh air into and pulls hot air out of the car to circulate air. I have a feeling GM did this so if you were driving and did not have the ac or heater on and the vent closed the fan would run to circulate air with the windows up. Its just one of those things that was done on some vehicles and not on others I have other vehicles that does not do this.

But now if the maker of this ac system says its not supposed to do that then I would look into it. But if the aftermarket system was designed to use the factory harness and hookups then I would say that the the reasion for the fan motor to run if its only running when the key is in the on position is this.