Hey everyone... just got some ls1 fans and the nelson harness from a friend for my 04 5.3. I have a few questions. Will the fans work without a toggle switch or do i have to get nelson to edit my pcm or find someone else with edit/hp tuners to make the fans work? I thought I read where they worked at low speed with the factory pcm? Im new to this so any info on those fans/harness for a 04 please lemme know. I just didnt wanna have to toggle my fans off and on.. espically if someone else drives my truck and they forget to toggle it on

 

The nelson harness has relays and are made to work without a switch. But you can run one temporarily as the only means of turning them on. You can alos retain a toggle and PCM control later on. The best bet is to do a switch and hurry and get the PCM changes made so you don't have to worry about forgetting (say you've had a beer or four...) or loaning the truck to someone and they forget to turn the fans on. Manual fans are nice when you want them but a PIA 85% of the time.

 

Definately gonna need a tune, otherwise its gonna be a PITA!

 

Yea, if you don't want to have to do it manually via a switch, the PCM has to be tuned for it.

 

well dang....

can hptuners do it if so, what needs to be done?

Thanks for the info btw

 

Also, is there a way for for the pcm to to call for high speed w/ out the ac being on....and does anyone have a wiring diagram that I can use to modify my set and make a switch for manual on low, manual on high, manual off, and auto.

 

Maybe I should controll the ls1 fans w/ my FAL controller.

 

throw your FAL controler away IMO.

 

i got my fans to come on the entire time the truck is running and i also have a toggle switch if i want to turn them off

 

yeah just use the nelson harness thats all u need mines never been over 180 i see no need to turn em on with a switch.. i mean if its really hot your prob gonna have the ac on which turns 1 fan on.. and when it hits the temp thats 2 on hi which cools it down faast IMO