Dave-1970

So I have an LQ9 in a 70 chevelle. My radiator has two electric cooling fans. I have one fan wired up to be controlled by the PCM (low speed) and was contemplating having the second fan operated by a toggle switch on the dash. Should I just have the PCM control both or is there a good reason to have one fan manualy operated??? Thanks in advance!!

garys 68

iTrader: (1)

If you have AC, you might consider having the second fan controlled by the AC trinary switch as well as temp. Otherwise the ecu is ok alone for both.

itsslow98

iTrader: (18)

I see no benefit to the switched fan except for being able to turn it on when the car is off.

Agent_Orange_Shuvel

iTrader: (8)

If you plan on drag racing it much the toggle switch isn't a bad idea because you can leave the fan on while waiting in the staging lanes. Otherwise running both of them off the PCM works great.

LS88FoxBody

iTrader: (2)

I was going to just do switch controlled. But Computer controlled will be nice. Problem is making the normal switch work while switching ground too...

2xLS3

iTrader: (3)

Just use another relay with the contacts in parellel of the one controlled by the PCM, then run a switch to one side on the coil and ground the other side

Dave-1970

Thanks for the replies!! The car won't see the track too much and I would hate to leave it on and forget about it so I'm going to let the pcm do all the work...

danbo313

iTrader: (8)

Some info on how to do both.

http://www.hotrodlane.cc/ONLINETECH/...%20Wiring.html