Making dual electric fans work without having to segment swap

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February 17th, 2020
turbo_bu

Making dual electric fans work without having to segment swap

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).
February 17th, 2020
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
February 19th, 2020
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.
February 24th, 2020
nonnieselman

2 Attachment(s)

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.

Attachment 23199 Attachment 23200
February 24th, 2020
joecar

12212156 allows you to run dual fans F-car style using 3 relays.
February 25th, 2020
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.
February 25th, 2020
nonnieselman

Quote:

Originally Posted by 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.

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
April 18th, 2020
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?