2003 chevy Silverado efan conversion nightmare with HP TUNER

[jaysonnewellolson]

So dicided to bit the built and install the 6.0 3row alununuim radiator and efans in my truck. the truck was original a 4.8l and is now a blown 6.0l with a 4l80e swap. With a Nelson Performance HP tune. So when i had it tunned by Nelson Performance last year just before thanksgiving i had them program it for efans knowing that before holloween this year i would be doing the efan conversion. So I ordered up a bad ass radiator stock efans and the aftermarket harness to pin in to the ecm. Now time comes to install it all i pull out the fan clutch wont need this into the trash, fan shoud into the trash radator out side for the for the scrappers hoses into the trash. Then i install all the new stuff with new silicon hoses stainless clamps the stock fans and the new relays and harnes per the instructions avalible to us all via the interent. It should have worked perfectly right. No Not me Not so lucky. I started the truck and the fans came on at high speed right away the engine cold cold. I run it anyways and burp the system. I figureded ill figure it out the next day. So I plug in my Snap-on Ethos and go into the diagnotics and find the section for conntroling the ecm output controls ingictor silinoids fans basically you can turn everything off and on to check functionality. I start it up and what do you know the fans are on already and the engine is cold. I turn off and on both outputs and the fans go off and on in the cycles as they should. OK now we know that the outputs are connected correctly maybe its in the tune.
I contact Allen from Nelson Performance and we go back and forth email because he is in texas and I am in Cali. He says it is the harness and to buy his harness and it sould fix it so I buy tthe new harnes. Then wait a week to get and then i install using his instructions the same exact way i had just done the othe pin out. What do know same problem. I start the motor cold and the fans are on full speed humming away. I then go through the whole thing again check the ecm output yep throwing a ground, snap- on tool check the on off function yep that works. Now its been a month and i cannt get these efans to work right. Allen has no answer, all i get is hes done 1000s of these efan conversions and never seen this before. My questionis has anyone on this hp tunners forum ever seen this problem when using an hp tune.

[2xLS1]

You're going to get absolutely nowhere without seeing what the fan settings are in the calibration.

[jaysonnewellolson]

You're going to get absolutely nowhere without seeing what the fan settings are in the calibration.

Yep I was hopeing some one may have incountered this issue and i could speak with the tunner and see if there would be a solution.

[TowinDaLine]

Posting this because I just got through installing e-fans in my '03 Sierra a few weeks ago. I did *not* encounter the listed issues as described by the OP. Although I will say that if A/C is commanded on, the fans will start up rather quickly, even if the engine is cold. So if you live in a warmer climate and run the A/C a lot, that might contribute to why they're coming on so soon.

This is from a P59 controller for a 6.0L LQ4, and is how I found the configuration before modifying it. You may (or may not) have had the same settings in your ECM... Do *NOT* use these settings... they need to be massaged (I can post mine, if desired and I'm not breaking any rules to do so)

Screenshot 2021-10-19 211727.jpg

Note that the table in the shot is from the 'Control by %' / 'Desired vs. ECT' button. I posted it for reference -- and FYI, I did *not* modify the contents of that table.

The 'A/C' tab to the right requires modification, too. But this lets you see what was likely in yours before the tuner modified (?) it. Note that if it is configured like this, I would think you should almost *never* see the fans on (opposite of what the OP is experiencing).

Finally, I am using a harness from Amazon, not Nelson's, although it's built to the same specs, including the three 40A relays.

[jaysonnewellolson]

thanks for the info i would have thought this would have been just a plug and play.

[jaysonnewellolson]

So guys I asked if Allen from Nelson Performance in Texas if he could send me my tune with the efan controls deleted in my tune. I then downloaded the tune from the truck that was activating the efans, i installed the new tune what do know no efan activation. i then reversed the procedure and reinstalled the original tune and the fans come on at start up full speed with both fan control wires putting out a negative. this leads me to conclude my tune is defiantly wrong. Im leaning toward taking it to a local tuner here in Orange County Ca. any advise would be helpful. WHAT A NIGHTMARE. I have probable 80k into this truck and i cant even get a tune that runs the efans.

[blindsquirrel]

Can't spell and spent $80K on a pickup truck?

[bennytwostep]

I just did the same conversion, and with HP TUNERS, turned the fans on. I'm getting no action from pin 33 in the green connector. I can manually ground the wire, and the fans operate correctly, so the harness is good. Not sure what I'm missing.

[RDF1]

If you can post your tune that would be most helpful.
Ive only encountered a issue like this one time several years ago.. I finally did a Full-Flash (EFI Live) as a last ditch effort and it worked no problems after that. So it must have been something up with a Cal-Flash error.

Benny, did you change the Recirulation Fitted option to Fan #2 under System / AC ?

[RDF1]

I just did the same conversion, and with HP TUNERS, turned the fans on. I'm getting no action from pin 33 in the green connector. I can manually ground the wire, and the fans operate correctly, so the harness is good. Not sure what I'm missing.

Can you go to the manual controls in the scanner and test it that way?

[bennytwostep]

yes. i/ posted my tune in here. the key point here is that I cannot even manually turn the fans on in the scanner.