sup fellas
i'm thinking about buying some ls1 fans for my truck soon. i have heard and seen all kinds of different setups on them as far as wirering. do you have to program the pcm for the fans to turn on and off? also, can you rig up a manual toggle switch for whenever you want to turn them on or off. thanks...

 

If I were you I'd get a Nelson tune and get him to program in the fans, he also makes a harness which is about 80 or so, then just hook them up and it should work fine. You can also rig up a manual switch to turn them off. I am going with the Nelson harness and ls1 fans before too long

 

Yes, the PCM must be set to recognize fans are present. Secondly, the temps must be set for on/off conditions.

Yes. If using the PCM, then you would connect into the ground wire going to it (pin 42). Basically, you are then using the switch to establish ground, thus, overiding the PCM.

 

i think i will be going with the nelson harness, but here's the problem i'm having. i'm wanting to install fans, pully, shift kit, converter, and cam before i get it tuned at thunder racing. i want to install the fans before i go there. if i do that first, the fans won't work since they are not tuned to the pcm. any suggestions on what i should do to get them working so that i can drive there to get it tuned. thanks...

 

How much is that Harness anyways? And when set to the PCM will it kno when to shut off and turn the fans on. Or will a tune and a program from nelson do that.

 

As they said, I would go with the Nelson Harness ( mine should be here anytime) You could always have a switch. I plan on using a 3-pos switch (manully on- off-computer)
I already have e-fan on my truck, but I decided to go with a fan off of an older thunder bird or cougar with a v-8, Alot cheaper ( I only paid $50 bucks for mine ) and easier to find, plus its only one big fan and easier to install. I live in west Texas and have not had a problem.

 

I ordered my Nelson harness and tune this week. There is an option for a switch and LED with the harness or you can add your own.

 

hey 00Z71
that's a good idea about having the 3-pos switch (manually on- off- computer)
let me know how you set it up, like the wireing and suff. i'd be interested in doing mine like that. thanks

 

The way I thought of it on my truck ( remeber I only run one fan - should be the same for yours though) is to use two relays and run them using a neg. output, one for manual side and one for the computer, that way when you have it on manualy you don't send a ground to the computer.

 

cool deal