I just had my ls1 fans installed using the pcm to control them using this diagram:
http://www.ls1truck.com/howto/pcmfan...ng_frames.html
As can all see the fans are ground activated and only turn on when the engine temp reaches 188* and then turn off then the engine cools off to 182*.
With this set up, my fans are not turning on when the A/C is on untill the engine temp does reaches 188.
How would you remedy this situation since the fans are ground activated by the pcm and the green A/C wire is + when the A/C is on? In other words how would I provide a ground to activate the fans when the A/C is on.
I know the easies way to fix this issue is just to add a switch and turn them manually or better yet just have them running full time since we use the A/C year long here in south TX.
How are you guys who have your e-fans connected to your pcm dealing with this issue.

 

Hey Tib, you could use a relay to control the fans coming on with AC. I had to do this for a power circuit on a line lock for my nova and 2 stage rev limiter. Just use the switched power to send the ground to the fans low stage to turn them on and use the pcm to turn the high speed on. Thats atleast something like I plan on doing. Others may have other oppinions but thats my .02

 

You could use a A/C relay from Flex-a-lite, its fairly cheap and the fans come on everytime you turn on the A/C, no matter what your temp is at. I plan on installing my E-fans tomorrow and I bought the VSC which has a relay for temp sensor, A/C, and one for Manual off/on, I will let you know how mine goes. The only thing I cant figure out is what temp to set the VSC to switch the fans on at using my 160* stat. Also, I am not sure, but wouldnt you have to have the PCM retuned to turn the fans on when the A/C kicks in, if you are using the PCM to controll the fans and not a relay?

Also you should take a look at this if you are using a VSC

 

Going by that schematic you linked to.. just incoporate another relay where the manual switch is. Trigger the relay with the '+' signal from the a/c to provide a ground to the other two fan relays.

 

Thanks for the info guys.. I have it figuired out already. I am gong to do the opposite on the current set up with the 3rd relay just like this on fig B.
http://www.partsexpress.com/pdf/500-001.pdf