I've made my own harness for use with the LS1/LT1 fans. I'm looking for a ignition controlled ground thats under the hood and in the fuse box. Can anyone point one out for me.

I'm trying to get around having to pay $100 bucks for a harness, and then another $75-$300 for a coustom tune. So far I've made my own harness, just like the other guys sell. Now I need a ground that comes on with the ignition. Any help would be nice.

 

I just used a test light and turned the ignition on and off while backprobing leads under the fuseblock. Look for pink or red leads....mine was pink. Its just used as a trigger anyways to tell the fans when the truck is on/off. not for any real power source...at least if your using a FAL VSC.

 

red and pinks for a ground?

I know what VSC is. What's "FAL?"

 

sorry read it wrong....there are no ign. controlled grounds on this truck that I know of. There are things controlled by ground, but none that I can think of that happen to be ign. controlled (basically I mean non-grounded when off, grounded when on right?) How are you controlling these fans? FAL - Flex-a-Lite.

 

Correct ! When one of the grounds, is grounded via switch, or ignition the fans are on low. I'm using the A/C tigger as the "high" kicker for the relays to the fans.


I coppied the wiring from a guy over at http://www.monodax.com here's the post, ----> fan write up

here's the diagram.

 

oh so your looking for the wire to switch the fans to high when a/c kicks on. its under the fuse block. Look for the a/c relay, and figure out which of the 4 pins is the ground switched side, and your golden. I just back probed and turned on the truck and a/c and found the pin that way. If I had my wiring diagrams here, I could tell ya which pin it was, but don't. you have a 1 in 4 chance, sooooo. yeah.

 

ya know, if your gonna wire it to have the computer use it, ya should just do it the way GM designed it, so you can get full functionality.....check this out. https://www.performancetrucks.net/fo...2&page=4&pp=10

You can control tons of parameters in the PCM if you set it up like this. Your way kinda limits you.

 

hey I'm sorry, I just edited the post.

I'm able to have the fans kick on with a/c just fine. I'm guessing that I need to switch the constant "run" wire to the ignition, and relay it.

 

reading up. . . thanks !

 

oh, so you want them to run low all the time, and high when a/c kicks on right?