Fan 2 cuts on - off - on - off - on - off, you get the picture

Ok,

so i am doing an swap of a LM7 out of a 2000 GMC sierra 1500. it had a clutch fan and on my swap i installed dual electric fans that are wired seperately.

now in the manual controls of the software i can cut the fans off and on just fine, each on works individual so im pretty sure wiring is ok.

but when motor reaches temp to cut on fan 2 the relay just cycles on then off then on then off, you get the idea. note, i am not using the a/c run through the ECM, i have a vintage air unit taking care of the a/c unit.

i am posting my tune so maybe someone can help, i am not an expert, this is my first swap, so if i have made a dumb mistake, dont worry about hurting my feeling, just let me know what i did wrong.

also if you see anything else wrong in my tune file let me know. and other than the electric fans motor is bone stock, with emissions and vats removed.
will be changing to aftermarket cold air intake, but no further upgrades. for right now :)

anybody? any ideas?

here is a screen shot of what i have, could the a/c psi setting have something to do with it. i dont have anything from the a/c hooked up.

Go to System>A/C>General>Recirc Option ... set this to "Fan #2". You currently have this set to "AC Recirc".

You are using a 2000 model year truck OS. Some of the early truck OSs don't work well with E-Fans ... FYI

Quote:

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Originally Posted by Shrek

Go to System>A/C>General>Recirc Option ... set this to "Fan #2". You currently have this set to "AC Recirc".

You are using a 2000 model year truck OS. Some of the early truck OSs don't work well with E-Fans ... FYI

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I had this set to fan 2 originally, but fan 1 ran all the time the engine was running. changed this to ac recirc and fan 1 operated correctly, but 2 cycles on off.

are these two problems related or was my fan 1 something else.

thanks for the help

you also have Fan 1 to come on if temp is above 08F with ac.
May be that is why it was coming on.
Max out all AC table up or down to disable and then retry.

ok just so it is a little more clear in my head, since i am not using the air conditioner run through the ecm.

do i set the a/c values high or low to ignore them?

i set the fan 1 AC enable and disable press to 500 psi on both
and Recirc option to Fan #2

dont know if one or both fixed it, but it works now. :)

500psi high side???!!! r134a??? whew...askin for trouble, your kicking the shlt out of your ac compressor with that much head pressure! Thats like running full speed on treadmill wearing combat boots n double sweat suit!

Quote:

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Originally Posted by 94s10lsx

500psi high side???!!! r134a??? whew...askin for trouble, your kicking the shlt out of your ac compressor with that much head pressure! Thats like running full speed on treadmill wearing combat boots n double sweat suit!

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That is to enable fans as correctly and disable AC in tune as he does not have AC setup pcm controlled.

Um so I think your saying it never actually gets that high?

A 2000 truck OS is not configured for an A/C pressure sensor. The OP is not using an A/C pressure sensor (trucks of that vintage used high & low A/C pressure switches) - he just wanted to get the E-Fans operation.

yes thats whats i was doing, you beat me to the answer :)