OBS AC Wiring Help with 0411 5.3l Swap
#41
OK...I finally figured out how to make my wire chasing Toner work in a vehicle. It really does need an Earth ground sometimes, so I ran an extension cord and used the Ground from that.
That led to several intersting discoveries.
Namely the two non-connected plugs hiding behind the motor at the back left:
Those two (nearly?) identical plugs have continuity between them and (I guess) the other pin has continuity to C2 Pin 17. I can't tell if there's a white stripe or not.
The other plug, I don't know...does anybody recognize it? Dark Green and Black?
Thanks,
-Kyle
That led to several intersting discoveries.
Namely the two non-connected plugs hiding behind the motor at the back left:
Those two (nearly?) identical plugs have continuity between them and (I guess) the other pin has continuity to C2 Pin 17. I can't tell if there's a white stripe or not.
The other plug, I don't know...does anybody recognize it? Dark Green and Black?
Thanks,
-Kyle
#44
I just tried switching the connectors and it still didn't cycle on.
It's weird that it worked before, apparently without the High and Low switches, as they weren't there a few weeks ago either, and now I can't get it to go.
I expect that whatever that 2nd Round Connector is supposed to hook up to would make it turn on.
I guess maybe those Connectors can be re-pinned and maybe I can move the one wire to the other?
Thanks,
-Kyle
It's weird that it worked before, apparently without the High and Low switches, as they weren't there a few weeks ago either, and now I can't get it to go.
I expect that whatever that 2nd Round Connector is supposed to hook up to would make it turn on.
I guess maybe those Connectors can be re-pinned and maybe I can move the one wire to the other?
Thanks,
-Kyle
#49
My attempt (now in the dark) to determine that flat cables original function turned out to be fruitless.
I'll have to try again in the daylight as I have very poor night lighting currently.
Thanks,
-Kyle
I'll have to try again in the daylight as I have very poor night lighting currently.
Thanks,
-Kyle
#50
Lextech is the man for wiring LSx in OBS, 0411 ecm and a/c. If you are not contacting him, advise you to do so.
http://www.ls1truck.com/forums/lsx-t...acket-kit.html
http://www.ls1truck.com/forums/lsx-t...acket-kit.html
#52
https://ls1tech.com/forums/conversio...ps-others.html This thread has a simple but effective way of making a/c work without adding the rest of the pressure switches into the system. On the light green wire in his diagram you should have the switch on the accumulator interrupt the circuit between the HVAC unit and the PCM.
#53
So, I made an attempt to ground Red Pin 55 with the 2nd 'round connector' jumpered. It didn't seem to work.
I'm not sure if just pushing an 18awg wire in to the connector, hoping it would make contact to the ECM, should be good enough or not.
Should I be wondering if Pin 11 (11 DK BLU 604 Secondary A/C High Pressure Switch) should also have a connection?
I'd guess it's not necessary as this 0411 was working before, but I'm not sure what 'he' did to it yet.
I do have the before and after Tune Files, but I kind of doubt he went that far.
Maybe tomorrow I'll have time to head way out to someone local who offered to help out with the wiring on this.
Does anybody know if those Round Connectors can be de-pinned? I'd bet I'm going to need to end up with the wire going to Red Pin 17 moved to the connector with AC Request from the Dash connected to the Accumulator Switch.
Thanks,
-Kyle
I'm not sure if just pushing an 18awg wire in to the connector, hoping it would make contact to the ECM, should be good enough or not.
Should I be wondering if Pin 11 (11 DK BLU 604 Secondary A/C High Pressure Switch) should also have a connection?
I'd guess it's not necessary as this 0411 was working before, but I'm not sure what 'he' did to it yet.
I do have the before and after Tune Files, but I kind of doubt he went that far.
Maybe tomorrow I'll have time to head way out to someone local who offered to help out with the wiring on this.
Does anybody know if those Round Connectors can be de-pinned? I'd bet I'm going to need to end up with the wire going to Red Pin 17 moved to the connector with AC Request from the Dash connected to the Accumulator Switch.
Thanks,
-Kyle
#54
Is it possible to re-pin these connectors? How do they disassemble?
I think I need to move the Green w/White over with the Lt. Green wire and then would have A/C Request through the Accumulator Switch to Red Pin 17 and would (maybe) just need to ground Pin 55.
I'm still not sure why I wouldn't need Pin 11. How could I tell in the Tune if it was active or not?
By the way, where exactly ought I find the 'ground' for Pin 55? On the ECM, or run another wire to the Chassis?
Thanks,
-Kyle
I think I need to move the Green w/White over with the Lt. Green wire and then would have A/C Request through the Accumulator Switch to Red Pin 17 and would (maybe) just need to ground Pin 55.
I'm still not sure why I wouldn't need Pin 11. How could I tell in the Tune if it was active or not?
By the way, where exactly ought I find the 'ground' for Pin 55? On the ECM, or run another wire to the Chassis?
Thanks,
-Kyle
Last edited by kpeters59; 02-20-2019 at 05:30 PM.
#55
Did you ever get this figured out? I'm in the middle of wiring up some Efans to my 2000 OBS K2500 and am wondering how to get the ECU to control hi/low fan function as well as control for the A/C when it's on.
#56
Well, I haven't gotten that far.
Supposedly the wiring is installed for e-fans, but I/m still running the mechanical fan with no issues.
I did ground Pin 55 and the A/C is operating. But, it cycles on/off at a 7 sec / 15 sec rate.
I'm guessing that's because I don't have a high pressure switch on Pin 11, but I'm not sure.
I get cold air, but I'm pretty sure it could be better. Summer in S/E Texas is coming, so I guess I'll see if it needs more attention.
I think if you hook up your e-fans, they'll work as expected with the default programming. That's what my intentions are.
I, however, am NOT the expert, at all...
Thanks,
-KP
Supposedly the wiring is installed for e-fans, but I/m still running the mechanical fan with no issues.
I did ground Pin 55 and the A/C is operating. But, it cycles on/off at a 7 sec / 15 sec rate.
I'm guessing that's because I don't have a high pressure switch on Pin 11, but I'm not sure.
I get cold air, but I'm pretty sure it could be better. Summer in S/E Texas is coming, so I guess I'll see if it needs more attention.
I think if you hook up your e-fans, they'll work as expected with the default programming. That's what my intentions are.
I, however, am NOT the expert, at all...
Thanks,
-KP
#57
If it is cycling on/off then you have at least 1 functioning switch. You can "trick" the system by grounding the other missing switches. You can see my post here;
https://ls1tech.com/forums/conversio...a-ls-swap.html
If you go to the LAST post you will see that there is only 1 wire coming off the back of the dash mounted A/C controller, that then runs directly from the controller to the high pressure switch, and then the 2nd wire on the high pressure switch goes to the PCM. Again, last post will tell you exactly where each wire goes. If you are missing a switch, or switches, you can just ground those pins on the PCM and the computer will "think" those switches are present and working. You must still have at least 1 switch to allow the system to cycle. I would assume your tuner simply used the single wire from the controller, to the high pressure switch, then on to the PCM, as the cycling switch-which will work as long as the other PCM switch wiring is grounded. If it's too challenging trying to find the factory connections you can EASILY make your own stand alone harness for the A/C system and tie it into the 411 PCM. In fact, it would almost be faster to just make your own harness. But, if the wiring is all there, a little probing should help you figure out what is what and you can then tie it all back to the PCM.
The short cycling time you are experiencing could also be related to a low freon condition. Since you have it cycling, the wiring might be okay.. Throw some gauges on it and see what the pressures are doing when the compressor cuts on, and then off.
https://ls1tech.com/forums/conversio...a-ls-swap.html
If you go to the LAST post you will see that there is only 1 wire coming off the back of the dash mounted A/C controller, that then runs directly from the controller to the high pressure switch, and then the 2nd wire on the high pressure switch goes to the PCM. Again, last post will tell you exactly where each wire goes. If you are missing a switch, or switches, you can just ground those pins on the PCM and the computer will "think" those switches are present and working. You must still have at least 1 switch to allow the system to cycle. I would assume your tuner simply used the single wire from the controller, to the high pressure switch, then on to the PCM, as the cycling switch-which will work as long as the other PCM switch wiring is grounded. If it's too challenging trying to find the factory connections you can EASILY make your own stand alone harness for the A/C system and tie it into the 411 PCM. In fact, it would almost be faster to just make your own harness. But, if the wiring is all there, a little probing should help you figure out what is what and you can then tie it all back to the PCM.
The short cycling time you are experiencing could also be related to a low freon condition. Since you have it cycling, the wiring might be okay.. Throw some gauges on it and see what the pressures are doing when the compressor cuts on, and then off.
#58
I'm using the Accumulator switch. Whichever one that's called. Some have called it the Low Pressure Switch, but I have one diagram that seems to show the Low and High Pressure Switches on the Compressor, so I don't know.
Basically, I've got the A/C Request from the Dash going through the Accumulator switch onward to Pin 17.
Pin 55 is grounded.
Pin 11 is open.
If the on/off cycling wasn't so regular I'd think it was the Accumulator Switch doing it, but I'd guess it's the ECM looking for the Pin 11 Signal.
I suppose I could see if pin 17 is losing 12v at the time, but I haven't tried that yet.
Thanks,
-KP
Basically, I've got the A/C Request from the Dash going through the Accumulator switch onward to Pin 17.
Pin 55 is grounded.
Pin 11 is open.
If the on/off cycling wasn't so regular I'd think it was the Accumulator Switch doing it, but I'd guess it's the ECM looking for the Pin 11 Signal.
I suppose I could see if pin 17 is losing 12v at the time, but I haven't tried that yet.
Thanks,
-KP
#59
I need to confirm on my truck, but from what I understand from the Previous owner, the A/C is wired as follows:
Blue 42 - Fan 1
Red 11 - A/C Cycling Switch
Red 17 - A/C Request Signal (from dash board)
Red 33 - A/C Recirc. or Fan 2
Red 43 - A/C Clutch Relay
Red 55 - A/C Low pressure switch
I found out that my ECU is already been flashed for dual fans and the appropriate A/C on/off settings so what I'm hoping is that I can plug into the two pins for my fan control and I'll be all good to go. Hopefully this helps.
Thanks,
Ryan
Blue 42 - Fan 1
Red 11 - A/C Cycling Switch
Red 17 - A/C Request Signal (from dash board)
Red 33 - A/C Recirc. or Fan 2
Red 43 - A/C Clutch Relay
Red 55 - A/C Low pressure switch
I found out that my ECU is already been flashed for dual fans and the appropriate A/C on/off settings so what I'm hoping is that I can plug into the two pins for my fan control and I'll be all good to go. Hopefully this helps.
Thanks,
Ryan
#60
The wire from the back of the HVAC controller inside the vehicle does not go straight to the PCM-it passes through the high pressure switch on the back of the compressor FIRST, then the 2nd wire in the connector @ the high pressure switch then travels on to the PCM.