electric fans wont turn on

[Rad_richie]

I've been searching and can not get my fans to work. at all. 2004 tahoe ECM 5.3 engine without a/c
pins are seated well in the plug, I'm using 3 relays and have checked them manually and they work both low and high speed with ground being applied like ECM would do ( if I read how to do it right )

here's my current settings from previous try.
enabled analog cycling from not fitted
changed low speed to 195-188 from 203-198
high speed 203-193 from 210-199

I've tried aux fans and 2 fans, I've messed with delays which went from 0.0 to now first stage enable .3 disbale .2 min time 90.0 and second stage enable 45.0, disable .3 time 210.
I havent tried serial cycling yet, but at this point I'm trying anything, and maybe thats why these look f'd if they are really indeed f'd up.

Could someone please help me out here ? I'm a total noob with this, but I have got the truck to start with no DTC's and she runs great. even logs speed correctly with gears and tires

Thanks for any help. I truly appreciate it

[blindsquirrel]

If you have no A/C, then you have no low side pressure (cycling) switch, so that should be set to Not Fitted. That setting is solely for how the fans should interact with the HVAC. No HVAC integration (or none at all), = Not Fitted.

Can you command the fans on low/high/off with the controls in the scanner?

[Rad_richie]

I figured that was the case at first, and from all I read initially that was my part of first settings. It was Not fitted. I've been trying multiple configurations since trying to get them to work.
I am unable to try the scanner on the truck due to not having a PC laptop. Im down everything on my sons gaming computer.

I will say that last night I got one fan to work at temperature. it was weird though. only one fan came on at 205, and that was triggered by pin42 which soukld have made the fans turn on at 195. I went and tested my wires and it is indeed wired correctly and has the correct continuity.

I'm going to go back outside and unwrap all my wires to triple check, but even with a testing the circuit last night (applying ground like the ECM would) the fans worked proper. again, continuity is correct also for pin42 blue , and pin33 green.

other than changing back to not fitted, do you have any suggestions on where else I should possibly work the settings ?

[blindsquirrel]

Being able to command the fans on with the scanner will answer a lot of questions you just can't in any other way.

[Dahl]

https://forum.hptuners.com/showthrea...r-lack-thereof
Ive been searching on how they operate and theorys just to get my efans set up on 03 2500, this thread healp explain it .. hope it helps good luck ...

[charlie kelley]

i would simple call summit and get a fan control unit for your fan or fans i did that with mine as well and even wired up a toggle switch for them so i can turn them on or off when i fell fit

[charlie kelley]

i would simple call summit and get a fan control unit for your fan or fans i did that with mine as well and even wired up a toggle switch for them so i can turn them on or off when i fell fit
i would check fuse and the wiring

[blindsquirrel]

ya i mean why build anything when u can just hand over ur credit card thats what id do too kthxbye

nice 1 about the toggle switch,,, also if you want varible speed fanz u can jus flick the switch on n off relly fast cool idea

(edited because I accidentally used a proper ellipsis instead of the common-man's version with three commas)

[charlie kelley]

dude, i dont know what that post was about..im simply saying if every things checks out get a fan controller.. theres alot of benefits for my self for it .. i live in Nevada.. and having the the choose to command 100% duty cycle for the fans is a great thing for me..after a pass at the track i can let it sit there and cool down after the run.. hope you find out the problem your having and get it fix..good luck and ps the fan control have built in speeds i can just command mine 100% when ever i fell fit too