ac wiring

[70inbville]

Does a person need to leave the ac related wires in the harness for recognition of the computer? I have been looking at the pin out stuff at lt1swap and a/c related wires are said to not be needed. I am going to run vintage air in my truck on a 6.0 and don't want to take out wire from the harness that I need.

Thanks,

Chip

[LockDoc]

Originally Posted by 70inbville

Does a person need to leave the ac related wires in the harness for recognition of the computer? I have been looking at the pin out stuff at lt1swap and a/c related wires are said to not be needed. I am going to run vintage air in my truck on a 6.0 and don't want to take out wire from the harness that I need.

Thanks,

Chip

I was debating that too. I have an under dash air unit. I went ahead and removed them thinking the system could be stand alone.

LockDoc

[70inbville]

Thanks for the reply, I just don't want to take away the computers ability to protect the compressor at higher rpm's. SO much to consider when doing this swap, and how it all fits together. I'm about to wear out the search here, thanks to all for the great info.

[ls1nova71]

Originally Posted by 70inbville

Does a person need to leave the ac related wires in the harness for recognition of the computer? I have been looking at the pin out stuff at lt1swap and a/c related wires are said to not be needed. I am going to run vintage air in my truck on a 6.0 and don't want to take out wire from the harness that I need.

Thanks,

Chip

It can be done either way, but a lot depends on what year and OS you're using. 99-02 trucks are pretty simple, and require a high and low pressure sensor. 03-06/7 are serial data A/C request, but can be changed now with tuning software to be like the older trucks. 98-02 F body requires a 3 wire pressure sensor. That said, it really doesn't need to be run through the PCM. If you're worried about over-revving the compressor, then just reach up and turn the A/C off before getting crazy racing anybody. Your original A/C system didn't have any protection of that nature and they survived.

[70inbville]

Thanks guys for the info.

[LockDoc]

Originally Posted by 70inbville

Thanks guys for the info.

x2

LockDoc

[homemade87]

I have a 04 silverado system . I used the 82 controls to turn it on. I am also using the 82 low pressure switch just like the truck came with so if I loose pressure it will shut off.

On the other hand I did use the computer to control the high pressure side with the trinary switch from the 04 system. This is what controls the fans and over pressure. It controls the dual fans set up just like factory. On when needed off when not. All controlled by the trinary. This also created a delay for the compressor and fans at start up.

I also have the engine temp controlled by the pcm . Once you get up to about 35 mph the fans are no longer needed so they shut off (engine and a/c). They will come back on if needed above that speed . It all worked out good for me.

[plumber452]

I just ran across this old thread and was wondering how you got the serial data line to "Tell" your PCM that you were requesting A/C