so im working on a my ac for my dd ls iroc im currently looking for the connector that is mounted on the high pressure switch or switch.. . a 3 wire connector that is mounted on the hard line. im searching for the wiring pin lay out since these go to the pcm as well as the color/ schematics i was wondering if there is any who has functional 4th gen hvac controllers any input on the vaccums etc. any input would be great

those 3 wires to run to the PCM. IIRC they are in the RED ECM connector. I dont have access to a pinnout right now so i cant tell you the colors and which pins they are.

yeah i believe two go to the red and one to the blue.. but im not sure.

This might be the diagram you are looking for:

FIG : Compressor Controls (V8 LS1)(c) (2002)



C1 is blue, and C2 is the red

here's the address if you want a better view or if you want to print it out:
http://www.autozone.com/autozone/rep...00c15280277a49

I think I saw your post on LS1tech and you asked about the 3-wire a/c refrigerant sensor connector, well anyways there is a company on ebay that sells them I just bought one yesterday.


http://cgi.ebay.com/ebaymotors/GM-A-...Q5fAccessories

thanks guys.
exactly what i needed.


know it figuring out how to use the 3rd gen hvac harness and vacums onto the 4th gen hvac controllers.

It looks like you will be using almost everything from the 4th gen except the blower motor and heater core mounted in your hybrid HVAC box?

4th gen Parts:

AC Compressor
Condensor
Drier
HVAC Controls
AC Pressure Switch

3rd Gen Parts:

AC Blower Motor

I found this for the 3rd gen AC wiring diagram.




I believe you will bypass all the 3rd gen wiring and just mimic the 4th gen wiring diagram except for the blower motor which i haven't looked up yet on the 4th gen.

From the 4th gen diagram we know that you have to run these wires to get the AC compressor running with the PCM and AC Compressor Relay.

1.) C2 Pin17 (DK GRN/WHT) A/C Request I see it runs from your PCM to the HVAC Controls.
2.) C2 Pin14 (RED/BLCK) A/C Refrigerant Pressure Sensor Signal goes to the AC Pressure Sensor as “C”
3.) C1 Pin 41 (GRY) 5 Volt Reference (A/C Refrigerant Pressure Sensor) goes to the AC Pressure Sensor as “B”
4.) C2 Pin 57 (PURPLE) Low Reference goes to the AC Pressure Sensor as “A” as well as ...???
5.) C2 Pin 18 (DARK GREEN) A/C Compressor Clutch Supply Voltage goes to the AC Compressor Clutch relay, AC Compressor Clutch, and AC Compressor Diode.
6.) C2 Pin 34 A/C Clutch Relay Control also goes to the AC clutch relay

7.) You have 2 wires that are “Hot in Run,” a BROWN wire coming from the HVAC Control Assemble and a PINK wire distributed to the AC Clutch Relay.


Now you need to figure out how to run the 4th gen runs the AC Blower and how to hook up the vacuum lines. Anyone have the schematics for the 4th gen AC Blower?

i believe the blower motor is controlled by the blower resistor consist of yellow light blue and tan .. the havc has a has a brown wire supply and i think an orange since it needs 12 v with ignition and ground coming from the 3rd gen harness by the engine but its all controlled by the hvac controller.

i have to feed the ac request somewhere on there.. anyone know?

ill be running a relay for the ac
1 the ac clutch relay control
2 ac compressor supply voltage
and i believe it needs two hot in run

Good work on the HVAC box. I told you it wasnt that hard

I sent you a PM about some of your questions...but Ill respond here as well.

You should know where to get the AC request from now.

But something that I keep getting confused about is what exactly all your are using/doing in your interior. Did you remove all of the thirdgen wiring and controls? Or did you leave everything int here, and are just trying to hook up the 4th gen HVAC controls.

Because I swear there is a write up on making the 4th gen controls work with the thirdgen wiring.

Your LS1 wiring...does it have the connector and wiring for the compressor clutch? If so, i still dont understand why someone would remove the pressure switch wiring, but leave the compressor wiring. It all belongs in the engine harness. You only need one relay for the system. The diagram posted above for the LS1 looks accurate. Just a regular 30amp bosch relay will work just fine...from autozone or napa or even walmart probably.

Ok...the diagram for the 3rd gen that is posted above. Look at the "A/C CONTROL HEAD (MANUAL)" picture. On the left, you'll see the MAX, NORM and BI-LEVEL are bridged. This means that when your selector is on one of those, you are telling the system you want A/C. 12volts will then travel down the LT GRN wire. Then depending on your VIN/options it goes through the switches down to the compressor. See what I meant about the pressure switches being a series of "go/no go" switches? If any of those switches are open, meaning a pressure issue, the 12v never gets to the compressor. That LT GRN wire is what you want to run to the "A/C REQUEST SIGNAL" on the PCM...pin 17 in that diagram. You'll have to verify the pin number but it sounds familiar. Everything after that LT GRN wire in the thirdgen diagram can be removed. That diagram looks overly complicated. Mainly because it includes other circuits. The haynes manual shows good diagrams of the 3rd gen HVAC system. Simplified too.

You might want to do some searching around and PM some of the guys that have been running full 4th gen dashes. Assuming they are running HVAC, they should be able to help you on the control wiring side of things...

Wow...that was a lot of typing. haha.

J.

im going to run the relay sometime this week and buy the pressure switch connector. hopefully soon ill take care of this

thanks for the info guys