AC options- LS swap to 57 truck

[FAKKY]

So like most people I *think* I'm going to have a clearance issue on passenger side frame for AC.

If I understand correct ....... Im going to need

1) a high mount adapter
2) a non variable compressor

Seems this will be a $500 switchout .... so just seeing if I have this right or other options ?

I'll also have to put the engine back in and get better measure - I am 'close' to being able to fit it in stock ... but unsure what clerance I need for flex and lines etc and have also heard of people notching frame.

Any good links/reads ?

thanks

[Clyde65]

I believe Holly has some LS ac mounts that bring the comp in further.


https://www.holley.com/products/acce...y/parts/20-159

Also Dirty Dingo has one

[FAKKY]

Originally Posted by Clyde65

I believe Holly has some LS ac mounts that bring the comp in further.


https://www.holley.com/products/acce...y/parts/20-159

Also Dirty Dingo has one

Yeah - I read about that they offer the tightest fit in terms of width to help maybe gain a bit more ...... just not sure if it will be enough.

Sounds like some people are running the OEM variable displacement compressor also ......

So --- who has some real world details on what they like/used and why.
Or if not their own - just really good threads.

[Hart_Rod]

Holley setup...

[FAKKY]

Good Lord - swap trucks ^^^

Assume thats this bracket.
https://www.holley.com/products/acce.../parts/20-134P

So almost $500 between the bracket, pulley, belt and compressor.

Which AC system are you using.

[Hart_Rod]

Originally Posted by FAKKY

Good Lord - swap trucks ^^^

Assume thats this bracket.
https://www.holley.com/products/acce.../parts/20-134P

So almost $500 between the bracket, pulley, belt and compressor.

Which AC system are you using.

Yes. VA Gen IV.

[FAKKY]

Nice.

Really trying to see if there are options to use the factory compressor, I know there are arguments over variable versus static displacement.

Meaning ...... aware you can use a sanden/high mount to the tune of $500 ....... then add on the VA kit for $1k [underdash] to $1500 [surefit] just wondering what other options.

My AC will be tight on low mount - but it might fit.

[Clyde65]

I have mine on the stock bracket and compressor. 2002.

I use Old air Products and it all works great.

[FAKKY]

Good to know ^^^

Clyde is that in your build thread ?

[Clyde65]

The build thread on my signature is of my 69 Lo Liner Camper.

[FAKKY]

Hart Rod/Clyde65 - do you guys have a explanation on the wiring.

Seems most of the setups are

1) PCM controlled for 1 or 2 fans to activate on off (in pcm with hptuners etc)
2) When you add AC you need a way to control the activation of fans when compressor cycles ..... so a trinary switch

Sound right ?

Whats that look like - how did you do yours.

[Clyde65]

My AC isn’t pcm controlled at all, it’s stand alone like with my SBC . I have a tri-nary switch for the fans one runs at 185-190 and the other one comes on with AC or 205( I think)

[FAKKY]

Originally Posted by Clyde65

My AC isn’t pcm controlled at all, it’s stand alone like with my SBC . I have a tri-nary switch for the fans one runs at 185-190 and the other one comes on with AC or 205( I think)

Dang.
Thanks.

Yeah I think the LS swap allows PCM control of the fans.

From LT1SWAP

Fan Controls 1,2 - GM PCM's typically will control electric fans, usually 2. The PCM will supply the (negative) or GROUND signal to turn on fan relays. YOU CAN NOT DIRECTLY CONNECT PCM FAN CONTROL WIRE TO FANS

Pin 33 FAN For Fan replay control #2
Pin 42 FAN For Fan replay control #1

Not sure what exactly that looks like.
Basically trying to decide between

https://www.summitracing.com/parts/d...xoCDi4QAvD_BwE

or

Using a prebuilt relay harness similar to two fo these
https://www.bp-automotive.com/produc...an-or-nitrous/

and then wiring correrctly ...... given AC signal wire also.


I think the dakota options is my best bet , along with a trinary switch for AC.

[Hart_Rod]

Originally Posted by FAKKY

Hart Rod/Clyde65 - do you guys have a explanation on the wiring.

Seems most of the setups are

1) PCM controlled for 1 or 2 fans to activate on off (in pcm with hptuners etc)
2) When you add AC you need a way to control the activation of fans when compressor cycles ..... so a trinary switch

Sound right ?

Whats that look like - how did you do yours.

Depends on the year of the computer setup, but most will control the fans based on temperature of the engine. Some will kick on the fan when you turn the a/c on. But most require you to wire in a binary or trinary switch.

[FAKKY]

Originally Posted by Hart_Rod

Depends on the year of the computer setup, but most will control the fans based on temperature of the engine. Some will kick on the fan when you turn the a/c on. But most require you to wire in a binary or trinary switch.

Yup - thats the part aftyer more info - got a link or more detail ?


*think* it something like

a) Set both fans to come on at say 180 degress in PCM file
b) Set Fans to both com on also when compressor is enaged via trinary switch

But not sure how .....

1) This is wired up
2) How its done if you use both fans at same time or hi/low
3) What other considerations etc

[ls1nova71]

If you already have PCM controlled fans, then just tie the trinity switch ground output to the high side fan output from the PCM. This will trigger the relay by the trinary switch or the PCM. It may cause a check engine light, but the error reporting can be tuned out.

[FAKKY]

Dont have anything yet - just planning forward.