SSM 49264 - Climate Control Temperature Will Not Adjust With Clicking/Snapping Noise From The Dash

[Bob#3]

I completed the job of replacing my heater box this past weekend. Earlier in this thread someone (@airline tech ?) asked for a video showing the operation of the blend doors - once I had my old one out, I removed the motors from it and shot this video:



A few tips for anyone who attempts this job:

It's a pretty big one. I set aside both Sat and Sun to get it done. I started around noon on Sat, and worked for about 6 hours on it that day. Stopped after removal of the old blend box and install of new one, but left dash removed. On Sunday I started up around 10 am, and was completely finished with all the tools cleaned up before 3:30. I was not in a particular rush, and ran in to a few tricky complications due to some custom wiring I've added to this truck (trailer brake controller, amp power steps, dash cam, auto-fold mirrors, etc etc) that all have wiring running in and around the driver side footwell/dash... as a result, I could not easily completely remove the dashboard from the truck, and had to leave the driver side pretty close to the firewall. I was able to swing the passenger side all the way out far enough to give plenty of access, but it was a little tight sliding the old blend box off the AC condenser as a result.

Take LOTS of pictures with your cell phone as you go. Especially useful were the photos I took of specific wiring loom routing. When you pull the dash off, all the factory looms attached to the dash will be unplugged and all the routing will be changed up when you go to re-install. Having reference photos for what went where saved me a lot of frustration and time.

All the electrical connectors from the factory have some sort of release mechanism that should be *easy* to use...i.e, very little actual force is required. Sometimes though, it's really difficult to tell where the release tab is, or what direction to move it. My rule of thumb was if it took more than a little pressure from 1 finger, I was not doing it right, and should re-think how the connector worked. I did not break any electrical connectors during this entire job.



If you don't own a headlamp, buy 2 rechargeable ones before you start this job. Keep one charging while you use the other one. You'll need extra light basically the entire time.

You do NOT have to drain coolant or evacuate the A/C to complete this repair.

Chock the tires, and put the truck in neutral *before* you disconnect the battery. You have to chock the tires because you will have to release the parking brake to remove the center console and to make clearance to put the dash on the seats when you get to that point. If the truck is left in park, you'll have a really hard time getting the center console out...but there is a secret release mechanism:



There are 2 screws on the blend box itself that have to be both removed and re-installed by feel - they are on the firewall side of the box, sandwiched between the box and the firewall. There is *just* enough space to get a super stubby screwdriver back there, or, if you have a mini ratchet with a phillips bit, that will work well (and is what I used):



The single bolt that is located near where the dashboard meets the windshield on the passenger side was the single biggest pain-in-the-neck fastener in the entire project. I recommend just using an allen wrench/key to back the bolt out a half turn at a time until you are about to hit the windshield with the wrench, then switch to a pair of pliers to just grab the head of the bolt and spin.

You WILL need another set of hands to both remove the dash and re-install it. It's heavy, it's awkward, and lining things up on re-install was especially challenging. My wife helped me, and I'm happy to report that in spite of the experience we are still married.

I'm also pleased to report that the new blend box is working perfectly, and my truck's climate control is back to doing what it's supposed to.

There are no new rattles, and the only casualties were a couple of broken clips on the door sill plastic plates that sit at the bottom of the doors next to the seats, and a small piece broke off a light pipe on the passenger-side footwell for the interior ambient lighting. You can tell I'm all broken up about this horrible damage. ;-)

All in all, I'm VERY glad I did this job myself instead of both trusting and paying a dealer to do it. If you are at all handy, have some time and patience, you can do this job too.

Thanks for posting your video--it’s very helpful!

Since you said in the video that you'd keep the old heater box around in case there were followup questions, I actually made an account on this site so I could ask you a question.

Can you check whether the white plastic linkage in the center of the screen at 2:21 in your video (i.e., the piece with the metal pin that is moved by the driver’s side blend door actuator) can be removed/replaced? That piece snapped in half on my truck and I'm trying to figure out if I can replace just that piece (working from underneath the dash), or whether I’ll need to replace the entire heater blend box.

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[quangdog]

Welcome to the forums, @Bob#3 !

 

[Bob#3]

Welcome to the forums, @Bob#3 !

A video response to my question and help sourcing a hard-to-find part? A warm welcome indeed!

That's exactly what I was asking about. I could see it from under the dash and had tried some light pressure to pry it off, but there was so much grease on the end that I didn't see the locking tab.

I'll send you a direct message to talk about mailing the part.

Many thanks for taking the time to help out a new member!

 

[Bsthroop]

Good news and bad news: I replaced my blend box today and it was a full day job. Worst parts were getting the new box on the AC unit and the mass of plugs on the drivers side near the fuse box, what a tangle. I will add some pictures of the process.

The bad news is with everything back together, I reconnected the battery and I get no key detected. The remote locks and unlocks as well as the touch unlock, but when I try to start just says no key detected. Have unhooked the battery a few times, locked and unlocked but no luck. Any ideas?

 

[IdahoRanger]

Good news and bad news: I replaced my blend box today and it was a full day job. Worst parts were getting the new box on the AC unit and the mass of plugs on the drivers side near the fuse box, what a tangle. I will add some pictures of the process.

The bad news is with everything back together, I reconnected the battery and I get no key detected. The remote locks and unlocks as well as the touch unlock, but when I try to start just says no key detected. Have unhooked the battery a few times, locked and unlocked but no luck. Any ideas?

I have nothing but @airline tech might be able to give some ideas.

 

[Frenchy]

Good news and bad news: I replaced my blend box today and it was a full day job. Worst parts were getting the new box on the AC unit and the mass of plugs on the drivers side near the fuse box, what a tangle. I will add some pictures of the process.

The bad news is with everything back together, I reconnected the battery and I get no key detected. The remote locks and unlocks as well as the touch unlock, but when I try to start just says no key detected. Have unhooked the battery a few times, locked and unlocked but no luck. Any ideas?

Assuming you have the Lariat with the keyless ignition, there should be a slot where the key goes. If you do have a physical key, then perhaps you forgot to plug something in?

 

[Bsthroop]

Assuming you have the Lariat with the keyless ignition, there should be a slot where the key goes. If you do have a physical key, then perhaps you forgot to plug something in?

Yes that will be the task tomorrow to look through all of the plugs.

 

[airline tech]

If all connectors were plugged back in a secure, then I think the BCM has fault codes locked in and has the PATs system locked out.

Get BOTH Fobs in the truck and place (1) in the back-up spot in the center cup holders.
Atempt to Start.

If still (No-Help)

Hook up Forscan and clear all codes that come up, mainly the BCM
and then do a BCM self test.
This should enable the Key Fob to be detected again.
If not, it should be triggering a code, that you can use to pinpoint what is not connected and should be the only code and or codes showing.

 

[airline tech]

BCM Connectors related to the PATs antennas to pick up that the FOB is in the Truck

C2280E
C2280G

Disconnect and Reconnect these, to ensure properly latched.

 

[Bsthroop]

BCM Connectors related to the PATs antennas to pick up that the FOB is in the Truck

C2280E
C2280G

Disconnect and Reconnect these, to ensure properly latched.

Thanks! I will check those out in the morning.

 

[Bsthroop]

Pics from the project:

Box replaced, ready to replace dash

This is a lifesaver for removing/replacing the back screws

All of the looms from the fuse box removed

Box removed exposing heater core

I removed the front seats which makes it much easier to move the dash around since I was by myself.

 

[Bsthroop]

If all connectors were plugged back in a secure, then I think the BCM has fault codes locked in and has the PATs system locked out.

Get BOTH Fobs in the truck and place (1) in the back-up spot in the center cup holders.
Atempt to Start.

If still (No-Help)

Hook up Forscan and clear all codes that come up, mainly the BCM
and then do a BCM self test.
This should enable the Key Fob to be detected again.
If not, it should be triggering a code, that you can use to pinpoint what is not connected and should be the only code and or codes showing.

If all connectors were plugged back in a secure, then I think the BCM has fault codes locked in and has the PATs system locked out.

Get BOTH Fobs in the truck and place (1) in the back-up spot in the center cup holders.
Atempt to Start.

If still (No-Help)

Hook up Forscan and clear all codes that come up, mainly the BCM
and then do a BCM self test.
This should enable the Key Fob to be detected again.
If not, it should be triggering a code, that you can use to pinpoint what is not connected and should be the only code and or codes showing.

Thanks, I did find a connector unhooked that went to the driver foor and now the touch lock works on that side. Reseated all plugs at the fusebox. Still getting no key so tried reset with Forscan. Below are the errors aftet reset.

 

[airline tech]

Thanks, I did find a connector unhooked that went to the driver foor and now the touch lock works on that side. Reseated all plugs at the fusebox. Still getting no key so tried reset with Forscan. Below are the errors aftet reset.

The bottom one (Interior Center Ant) is an ACTIVE fault, this is the issue.

There are 4ea total connectors between the BCM and the Antenna

You still have a connector unplugged, in the wiring under the center console.

C2280G = BCM Connector

The 3 remaining C312 / C315 / C325 are suspect as being disconnected.
and all are located beginning at the dash to console junction and then runs back under the console.

So, you need to doublecheck all the connectors you disconnected when you pulled the center console and associated panels for access.

C312 is a (21 Pin- In-Line Connector), it ties in other systems on that connector, which ties into all of the faults showing plus various systems such as the door speakers.
So, this one is HIGHY Suspect

C315 - Is a 2-wire (in-Line) connector, only feeds the Center Antenna

C325 - Is a 4-Wire (Connector) with only 2 wires, this connects to the Center Antenna.
I cannot find a clear diagram as to exactly where the antenna is actually mounted, but it is under the center console and it appears to be mounted on the console itself, just aft of the cupholders.

 

[Bsthroop]

The bottom one (Interior Center Ant) is an ACTIVE fault, this is the issue.

There are 4ea total connectors between the BCM and the Antenna

You still have a connector unplugged, in the wiring under the center console.

C2280G = BCM Connector

The 3 remaining C312 / C315 / C325 are suspect as being disconnected.
and all are located beginning at the dash to console junction and then runs back under the console.

So, you need to doublecheck all the connectors you disconnected when you pulled the center console and associated panels for access.

C312 is a (21 Pin- In-Line Connector), it ties in other systems on that connector, which ties into all of the faults showing plus various systems such as the door speakers.
So, this one is HIGHY Suspect

C315 - Is a 2-wire (in-Line) connector, only feeds the Center Antenna

C325 - Is a 4-Wire (Connector) with only 2 wires, this connects to the Center Antenna.
I cannot find a clear diagram as to exactly where the antenna is actually mounted, but it is under the center console and it appears to be mounted on the console itself, just aft of the cupholders.

You are amazing! It was c315 and it now starts and all errors including the blend doors have cleared. Thank you so much!

 

[airline tech]

Awesome!!!!

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