03 Suburban rear HVAC not working

[Celerity]

45 minutes ago, SpartanAutoworx said:

Look up the connector for c397

The two orange wires should have 12volt battery positive voltage

If that other wire is dead I would say you need to trace it back for a break in the wire. 

I bet you put 12volts to the wire you will be back in business.

I can do this... But "connector for c397".  I have no idea what this is, where to find info about it or what have you.  I'm simply at a loss. Maybe I'll fire up a webcam to see the glassy-eyed look in my dead, hollow eyes

 

I'll start the trace process, but some sort of diagram would be good.   I'm looking up any kind of diagram for this, but having no real luck except the diagram that Carn put up. And even that is confusing as hell.

 

I think I'm going to buy the new controller module anyway. $70 bucks for something that may solve it.  I may own my own business and "can take any time off that I Want" but that's about 3 hours per week as it turns out.

[carnau]

Wait before you do that. I am trying to make sure I am reading what you are saying right. You are checking the connector at the rear of the vehicle right? I see you said under the dash. I am gonna try to clean that schematic up for you.

[Celerity]

I checked the connector at the rear, yes. I did that today, I didn't do it before. 

 

Before I checked the wire under the dash, near the kick-panel. That was weeks ago. I'm going to pull everything apart again to check that again tomorrow.   The fuses I just checked again and I'm getting good results.

 

Now when I pulled the orange wire from the harness up front, I noticed that nothing from the HVAC controls worked anymore. That's why I think that even now that front orange wire is ok.

 

But at the back ? Nothin.  So I am trying to figure out now if that rear connector is after the control module, or before it. The control module has power in it's orange wire, and the smaller orange wire in that harness you're talking about has power - but the big orange wire does not. 

 

So should I look for some kind of open circuit, or should I replace the control module ?

[SpartanAutoworx]

46 minutes ago, Celerity said:

I can do this... But "connector for c397".  I have no idea what this is, where to find info about it or what have you.  I'm simply at a loss. Maybe I'll fire up a webcam to see the glassy-eyed look in my dead, hollow eyes

 

I'll start the trace process, but some sort of diagram would be good.   I'm looking up any kind of diagram for this, but having no real luck except the diagram that Carn put up. And even that is confusing as hell.

 

I think I'm going to buy the new controller module anyway. $70 bucks for something that may solve it.  I may own my own business and "can take any time off that I Want" but that's about 3 hours per week as it turns out.

 What is your email ?  The file size is too large to attach 

[Celerity]

PM Sent, and much thanks for your time and efforts !

[carnau]

Here I redid the schematic to make it easier for you.

 

Here is what I want you to do. I want you to check C397 at the rear of the vehicle using this. Let me know if Terminal A has power on it. If it does I want you to check Terminal C one more time at the Processor. 
Tell me what you find. This post is getting cluttered and you're checking stuff you don't need to. Just check this and let me know what you find.

[carnau]

Here are the locations.

[carnau]

28 minutes ago, Celerity said:

I checked the connector at the rear, yes. I did that today, I didn't do it before. 

 

Before I checked the wire under the dash, near the kick-panel. That was weeks ago. I'm going to pull everything apart again to check that again tomorrow.   The fuses I just checked again and I'm getting good results.

 

Now when I pulled the orange wire from the harness up front, I noticed that nothing from the HVAC controls worked anymore. That's why I think that even now that front orange wire is ok.

 

But at the back ? Nothin.  So I am trying to figure out now if that rear connector is after the control module, or before it. The control module has power in it's orange wire, and the smaller orange wire in that harness you're talking about has power - but the big orange wire does not. 

 

So should I look for some kind of open circuit, or should I replace the control module ?

There is not a little orange wire or you are in the wrong connector. There are only 2 connectors you need to be in right now.

The connector that connects to the blower motor processor. (thats a 3 wire plug) A - Black , B - Purple and C- Orange. You need to check the Orange wire in it which is terminal C
Then if you have no power there you need to goto Connector C397. Check the orange wire in it which is Terminal A

 

Just check those and only those. Then let me know what you found.

[Celerity]

40 minutes ago, carnau said:

There is not a little orange wire or you are in the wrong connector. There are only 2 connectors you need to be in right now.

The connector that connects to the blower motor processor. (thats a 3 wire plug) A - Black , B - Purple and C- Orange. You need to check the Orange wire in it which is terminal C
Then if you have no power there you need to goto Connector C397. Check the orange wire in it which is Terminal A

 

Just check those and only those. Then let me know what you found.

Ok, this is the first plug that I checked.

 

I found that black was ground, Purple and Orange both only had millivolts on it.  That's why I replaced the resistor pack with the new one.  When I wired the new one up (They are 5 wire now and I had to remove the other connector, solder this one in place and test)

 

Same results. Going into the resistor pack, there is no 14v.

 

But what I'm going to do is check these again, and report back.  I appreciate you and everyone going through the motions, so I'll happily repeat things that I did just to be sure.

 

Thanks !

 

[Celerity]

1 hour ago, SpartanAutoworx said:

 What is your email ?  The file size is too large to attach 

Thanks for the attachment, I am going to go through and thoroughly check these pins and make sure of what I see.  If I'm getting serial data I can even run the o-scope and get waveforms (I understand it's squarewave from the schematic that was posted before)

[carnau]

16 minutes ago, Celerity said:

Thanks for the attachment, I am going to go through and thoroughly check these pins and make sure of what I see.  If I'm getting serial data I can even run the o-scope and get waveforms (I understand it's squarewave from the schematic that was posted before)

If what you're saying is right we just need to figure out why you don't have power on the orange wire. We don't need to know about serial data or anything until the processor has power.

[SpartanAutoworx]

 Don't worry about the other wires just check for the two powers.  I've never seen any other issues in that slice pack. 

[Celerity]

Sorry I haven't responded yet today.  Busy day at work, and I dropped the Burb off at the transmission shop for a shakedown.  It's bucking and hesitating when going uphill in it's highest gear.  I'm running out of ideas with that too. It's not spark (At least I'm not convinced) and I'm getting no codes. It can idle all day, I can go up a hill in any gear and it doesn't happen.  If it's in lock-up it happens. Downshifting makes it go away.  

 

Either way, I wasn't able to get to the circuit today but I will ASAP. Thanks !

[carnau]

13 minutes ago, Celerity said:

Sorry I haven't responded yet today.  Busy day at work, and I dropped the Burb off at the transmission shop for a shakedown.  It's bucking and hesitating when going uphill in it's highest gear.  I'm running out of ideas with that too. It's not spark (At least I'm not convinced) and I'm getting no codes. It can idle all day, I can go up a hill in any gear and it doesn't happen.  If it's in lock-up it happens. Downshifting makes it go away.  

 

Either way, I wasn't able to get to the circuit today but I will ASAP. Thanks !

No problem. I just thought you figured out it was the rear wiring harness and would let us know it fixed it when you got your new one. I really feel like that's what we are gonna find but it could be anything lol.

[Celerity]

On 11/12/2017 at 6:35 PM, carnau said:

There is not a little orange wire or you are in the wrong connector. There are only 2 connectors you need to be in right now.

The connector that connects to the blower motor processor. (thats a 3 wire plug) A - Black , B - Purple and C- Orange. You need to check the Orange wire in it which is terminal C
Then if you have no power there you need to goto Connector C397. Check the orange wire in it which is Terminal A

 

Just check those and only those. Then let me know what you found.

Ok,I jumped into the trunk during a break.   I have nothing at either of these connectors.

 

No voltage at all, on any wire. Grounds are continuous though.    So that's at the fan resistor itself, and that C397 wiring block. Spartan also sent me a pin-out of that connector and the wires matched.  No voltage there.