I am using my LS1 fans and wanted to tune the truck today.

What settings should I start out with on my truck? I was going to copy my stock fan settings for my TA. Is that good enough.

Thanks in advance.

 

basically what I did.... Fans come on at 200*
go off 199*
60 second delay turn on
120 second delay turn off.

that should get you started.

 

So you only have a 1 degree duty cycle? How do you delay the turn on and turn off? I am using HP tuners.

I got them set right now for low at 210, off at 200, high at 220, off at 211.

But they never came on sitting in my driveway. Temp only got as high as 190 with A/C on. I think my thermo is bad.

When I turned the truck on with AC, the one fan was on high but then kept shutting down/restarting after a 30 seconds or so. I concluded I tapped the correct wire with the Nelson harness but is that correct operation for the fan to go on/off.

Also, when do the LS1 fans go low versus high speed. After I tuned it up, I went into the Scanner and used the turned the low on for a quick test and that worked but the high did nothing.

Thanks

 

Ok so how are yours hooked up?
What year is your truck?

Mine are either on Low or High. Read the bottom of that pic.

Ill have to look at your screen shot again to see, im using EFI Live.
Here is how mine are goin to be connected this weekend using another pin from the PCM. That way instead of Fan #2 kicking on everytime the AC Clutch engages it will go by AC Pressure.

Im thinking Nelsons harness looks similar to this one at the bottom? Id rather the PCM control the Fan#2 instead of the AC CLutch on the Compressor.

Again, depends on the Harness, the fans should go "Low" Speed when the coolant gets up to your set temp.

Here is what my "Harness" looks like.



Also when im messing with my truck it gets up to temp and sits there for a lil while before it starts to get any hotter.

 

The reason you cant Command the Fans on High with your computer is prob because the High side is connected to your AC... Command your AC Clutch on, that should do it..


Here is my settings.
This is with my BBmod on the stock Tstat. ~170*





Get me a screen shot of your General and AC Tab..

 

Nice Harness. Thanks for the diagram. That makes sense if the Nelson one is wired the same. My trcuk never even got hotter than 190 or so even with running around town so I'll have to lower the settings just to test it.

Truck is a 2000 and I grounded the one wire off the AC clutch.

 

I'll try that...or I'll just turn the A/C on. thanks

Attached.

 

Say it stays at 190 crusing down the highway.. your never goin to get it any cooler than that. so you really dont want the fans to come on at that setting, if it gets over that is when you want them to come on. Atleast thats my thinking.

When i had the stock Tstat in there i had mine set something like this. (EFI has a few more settings that this, but you get the idea)

Fan 1 On 200*
Fan 1 Off 195*
Enable 30mph
Disable 35mph

(if your Fan 2 is connected to the Ground of the AC Clutch this setting doesnt work)
Fan 2 on 205*
Fan 2 Off 200*


Ignition off 230
max out the time setting if you want to.



So HP Tuners doesnt have AC Pressure setting for the Fans? Just ECT?

 

yeah, just temp.

 

what temp is your thermostat??

if its 160 then you will set the low to come on at 185 and off at 175, high to come on at 190 and off at 183

your truck should run going down the highway at 178-180 temps if you have the 160 themo

you can mess with it as you want to get the best results, good luck.