climate control sdi info to turn on aircon

[bhopper]

Hey guys any of you know how to make a relay that would know the serial data code and switch on a relay to turn on the air con on a standard bcm .

i am wanting to do climate control conversion to a stock loom ,i have worked out everthing else just how to turn on the air con an dim am guessing it is trigered through the serial data line to the bcm so if anybody know how to make a relay that will read the code from the bcm would be great or no a way around it so i can do this , i know that it must send a signal through the sdi to the bcm to trigger the bcm to turn on air con so if anybody has any idea please email me on bhopperr@hotmail.com

[Holden202T]

i guess the first question would be what model car is it ?

i would have thought the relay would have been in the bcm for that ???

[bhopper]

Hey holden well in low level bcm the air con is triggered by 3.5 -12 v to the bcm witch turns it on but with the climate control module i am guessing that air con is triggered by the serial data info as i know every wire and what it does like with the rear window demister a wire that turns that on is 12 v so that is fine but there ni wire for aircon so i am guessing it triggered with a code in a higher level bcm so that what i was trying to find out if a relay could be made to read the code so i can trigger the air con i low bcm if not i could also make a switch that will trigger it would be nice if i could use the switch in module.
and its a vt commodores series one .
cheers chris

[Dec_head]

Are you sure it's not as simple as a configuration change using tech 2.
I know changing the dash cluster from a model with a different airbag setup had to be reconfigured that way.

[bhopper]

Hi there well i have emailed dr bob to see if he know if it can be done but ill have to wait back to hear from him.

[antus]

The green/white wire is a serial data (ALDL) connection back to the BCM.

[bhopper]

Hi ant well i have traced every wire in the climate control module and yes that the only wire now i have to figure out the green and white wire it must send a code to bcm to switch aircon on as opposed to the low level bcm which is 12 v triggered so that what i have try and figure out and see if somthing can be tech 2 or a relay can be built to rig it .

[bhopper]

Just had a thought so if i wired that up to the green and white wire to the pcm do you think that the pcm would read it and switch air con on or would it need the signal from the bcm .

Im not too sure of all the details but as I understand it the BCM controls the body devices so you should wire the green/white climate control wire to the vehicle ALDL bus (a single wire, goes between the OBD connector, the BCM, the dash, the ABS, the SRS and all the other devices. If it doesnt work it may mean you need the BCM from a car with climate control, and changing the BCM might mean other issues with keys and so fourth. If you can try it you might find it just works - i doubt they take the ability out to listen for a climate control device, but you never now. If it doesnt work research what you need to consider to change the BCM.

[bhopper]

he there thanks for the reply i am guessing its not guna work because of the diagram shows that the serial data line goes to bcm and triggers the relay in there so i am not shaugh i might give it a go as i have already ripped the loom out now and guna try the berlina loom i have so hopefully the abs dosent play games with the dash like all teh other users on jc have mention.

thanks for the replies i will keep trying as i woul liek to master it for climate control conversion wish it was as easy as the electric windows.

cheers chris

[antus]

I recon try it, connect green/white to the vehicle data bus and see what happens. Its a proper ALDL device, so it wont break anything. It'll just either work or not. Theres a decent chance that it will work and it'll be that simple. The data bus goes all over the place so there should be plenty of places you can tap in to it. All the major devices are on the same data wire, its just another one.