Making dual electric fans work without having to segment swap

[turbo_bu]

Looking for some help to verify that I can make dual electric fans work on a vehicle other than the Camaro / Corvette (e.g. - not having to do a system segment swap). I have gone through the code in a 2001 disassembly and think that I found out why the regular EFILive parameters won't allow it. There is another parameter that pertains to the 2nd fan which is not currently in the EFILive. I created a CAX file for this additional parameter that seems to make it work. I have checked in on my bench 0411 using a 2002 OS, but would like to have someone else verify it on an actual vehicle. If you are willing to give it a try please let me know (FWIW - I am pretty sure I can find the correct parameter in any 512 kB OS).

[robof16]

Running dual fans with Nelson harness in 2000 Yukon XL (12212156 OS)
G1203 set to "Series Parallel Fans"
G0106 set to "Fan #2 Control"
Fan settings from 2005 truck

[turbo_bu]

It sounds like you are using a 1 MB PCM in your swap. Yes, the 2005 truck settings do work, since that is the way they were setup from the factory. I am hoping to show that for the older 512 kB PCM's that you can make them work too. I am running an older version of EFI Live, and maybe somebody added in the parameters into the newest version to make it work too.

[nonnieselman]

Ive never had a issue running dual fans from a 12212156 OS.
What are you trying to do?
These are the settings i have been using.

2319923200

[joecar]

12212156 allows you to run dual fans F-car style using 3 relays.

[turbo_bu]

Yes, for the F body and Corvettes / Holdens, it works using 3 replays. The issue that arises is that there are two parameters which I believe are missing from the list which on say truck OS's, are set to zero which prevents Fan #2 from turning on. I would like for someone to try it to see if they can now get Fan #2 to turn on. My research is showing that you would NOT have to do any segment swapping to get Fan #2 to work. I think that you would also NOT have to hook up the A/C pressure sensor to get it to work either.

[nonnieselman]

Yes, for the F body and Corvettes / Holdens, it works using 3 replays. The issue that arises is that there are two parameters which I believe are missing from the list which on say truck OS's, are set to zero which prevents Fan #2 from turning on. I would like for someone to try it to see if they can now get Fan #2 to turn on. My research is showing that you would NOT have to do any segment swapping to get Fan #2 to work. I think that you would also NOT have to hook up the A/C pressure sensor to get it to work either.My fan 2 output works just fine on a truck OS.
Want me to send you my tune?

Sent from my SAMSUNG-SM-G870A using Tapatalk

[silentbravo]

This file will make it so the fans come on with A/C right? I bought the BP Automotive sensor kit, and have tried a few things but the fans do not seem to be triggered by A/C.

I'll give your file a shot. My fans do work fine based on ECT.

Any way to open up the CAX file and verify what it does or am I just at the mercy of loading it and hoping it works?