95 c 1500 ac and cruise signal wires

[Jeebalow]

Subscribing for info! I also have to hook up cruise on my 95 and am wanting to add the A/C request signal to bump up idle.

Here's a thread with good info.
http://ls1tech.com/forums/conversion...-solution.html
I think I will hook up a 12V signal when a/C button is pressed to the A/c signal request on the new PCM. Hopefully that will bump up idle.

On the cruise, I spliced dark green (to speedo) and dark green with white(to cruise module) together in hopes that that will provide the correct speed info to the cruise. My plan is to then connect the lt blu/blk wire to the pin 13 on red connector for a 99-02 pcm which is the cruise control engage input.

Also, I plan on keeping ABS by connecting pin 49 on red connector (128K vehicle speed output) to the brake pressure modulator valve white wire. Not exactly sure if this will all work, just what I have gathered might work from looking at wiring diagrams. please post on what you attempt and if it works. I will do the same, although I wont get to it for a few months.

[DRAGGIN95]

I am just wondering if the ac will work without the ac signal, it doesn't seem like the ac clutch would kick in at all without the other side of the circuit.

[Jeebalow]

You're using the stock 95 A/C right? If so, it should work as it did before as long as you kept the wiring for it. Is that what you're wondering? It should still work without the A/C request signal to the new PCM. It's not the old ECU that activated the A/C. The wire to the ECU just told it to raise the idle AFAIK.

[DRAGGIN95]

Thats what I thought, but I wasn't sure, yes I kept the OE ac wiring all intact, I don't have ABS anymore, and the only other issue is the one signal wire for the cruise, but I don't think that is going to be to bad, I may use your idea above on mine too.

[DRAGGIN95]

I have gone through my oe harness and removed all the extra wires except what is needed, I am integrating the ls harness and it in to one harness, I don't want anything extra.

[kewljay223]

Subscribing for info! I also have to hook up cruise on my 95 and am wanting to add the A/C request signal to bump up idle.

Here's a thread with good info.
http://ls1tech.com/forums/conversion...-solution.html
I think I will hook up a 12V signal when a/C button is pressed to the A/c signal request on the new PCM. Hopefully that will bump up idle.

On the cruise, I spliced dark green (to speedo) and dark green with white(to cruise module) together in hopes that that will provide the correct speed info to the cruise. My plan is to then connect the lt blu/blk wire to the pin 13 on red connector for a 99-02 pcm which is the cruise control engage input.

Also, I plan on keeping ABS by connecting pin 49 on red connector (128K vehicle speed output) to the brake pressure modulator valve white wire. Not exactly sure if this will all work, just what I have gathered might work from looking at wiring diagrams. please post on what you attempt and if it works. I will do the same, although I wont get to it for a few months.

As far as i know this will not work as the new pcm does not use 12v signal for ac request which is why this is somewhat of an issue for the older trucks. The new pcm im pretty sure uses serial data so i would think 12v to it might casue some issues....possibly expensive.... i just kept it wired like it was (with the exception of adding electric fan relays) and when the ac button is pushed or the knob is turned to defrost, that will trigger the pump coil to engage. The motor should (like mine and several others ive seen) sense the drop in rpm and kick it up a bit to keep from stalling and drop back down when ac is shut off. ive had no issues with it.

[Jeebalow]

As far as i know this will not work as the new pcm does not use 12v signal for ac request which is why this is somewhat of an issue for the older trucks. The new pcm im pretty sure uses serial data so i would think 12v to it might casue some issues....possibly expensive.... i just kept it wired like it was (with the exception of adding electric fan relays) and when the ac button is pushed or the knob is turned to defrost, that will trigger the pump coil to engage. The motor should (like mine and several others ive seen) sense the drop in rpm and kick it up a bit to keep from stalling and drop back down when ac is shut off. ive had no issues with it.

I got that information from the link I posted above the line you highlighted in red. Post #13 has the wiring diagram for an 02 camaro. The HVAC sends a 12V signal to the ac request according to that. Take a look:
http://ls1tech.com/forums/conversion...l#post16616051

[kewljay223]

I got that information from the link I posted above the line you highlighted in red. Post #13 has the wiring diagram for an 02 camaro. The HVAC sends a 12V signal to the ac request according to that. Take a look:
http://ls1tech.com/forums/conversion...l#post16616051

ok well i got my information from this thread, http://www.ls1truck.com/forums/lsx-t...tegration.html when i did my a/c a year and a half ago and it hasnt been updated yet. If you read through that, youll see that the guy in your link setup works because he is using the older 99-02 pcm which utilize the 12v signal. I got screwed on my end because i have an 03 and all 03+ use serial data from the HVAC unit which i doubt you will be able to replicate from some DIY stand alone unit. NOW im not sure which pcm you or DRAGGIN are using. if you guys have the older one, then you can both disreguard this post. but if either of you have the newer one like me, just keep it the way it was wired originally through all the pressure sensors and you should be good to go. the new pcm will sense the load and bump the idle up anyway. IF you are using E-fans, then you will need to get creative with relays like i did for them to kick on high like they are supposed to which is completely doable. my setup works great so far. Last option, be the first person to find a tuner that can change the input settings inside the pcm from serial data to discrete (good luck). IF YOU DO FIND SOMEONE, PLEASE POST!! anyway, hope that clears up my previous post.

[Jeebalow]

ok well i got my information from this thread, http://www.ls1truck.com/forums/lsx-t...tegration.html when i did my a/c a year and a half ago and it hasnt been updated yet. If you read through that, youll see that the guy in your link setup works because he is using the older 99-02 pcm which utilize the 12v signal. I got screwed on my end because i have an 03 and all 03+ use serial data from the HVAC unit which i doubt you will be able to replicate from some DIY stand alone unit. NOW im not sure which pcm you or DRAGGIN are using. if you guys have the older one, then you can both disreguard this post. but if either of you have the newer one like me, just keep it the way it was wired originally through all the pressure sensors and you should be good to go. the new pcm will sense the load and bump the idle up anyway. IF you are using E-fans, then you will need to get creative with relays like i did for them to kick on high like they are supposed to which is completely doable. my setup works great so far. Last option, be the first person to find a tuner that can change the input settings inside the pcm from serial data to discrete (good luck). IF YOU DO FIND SOMEONE, PLEASE POST!! anyway, hope that clears up my previous post.

I am using an 01 PCM so I should be good to go with the info in the link I posted, but you make a great point. DRAGGIN may not be able to use the same method.

I am using 06 silverado fans and harness. I will activate the fans with the a/c clutch engagement and/or the a/c button in the cab. From what I remember form thermodynamics and heat transfer, a steady stream of air would be better to dissipate heat rather than only when the clutch engages. I was also thinking about using a controller so the fans will not come on above 45 MPH because of the A/C (the PCM would still control them based on engine temp).

[DRAGGIN95]

Hello, I using a core 411 PCM from Nelson, set up to be like 98-02 ls1 computer, I am planning to just use the ac in standalone mode and try it like that. Now it's only the cruise left to deal with.