I have the dealer supplied Auxiliary switch upfitter package - how to get through the firewall on a 2024 3500 HD gas engine truck?

[Doug Krussel]

I've watched how to install everything on a 2022 HD but there is no nipple passthrough or anything I can see visually to get through the firewall.  Anyone know where they located the entrance on the 2024 HD trucks?

 

[Dr1ft3r]

https://www.gm-trucks.com/forums/topic/236815-lets-install-the-upfitter-switches/

[gemarsh]

16 hours ago, Dr1ft3r said:

https://www.gm-trucks.com/forums/topic/236815-lets-install-the-upfitter-switches/

He is asking for a '24, he said he looked for the older dash location for the pass thru, evidently gm changed that also.

[Doug Krussel]

Correct, the previous model years had a nipple that you simply cut the end off and used.  That is nowhere to be found...or at least I can't find it.  I can do the old cut the boot method but I'd rather not if there is something to use and I'm just not seeing it.

 

[newdude]

GM Upfitter has an instruction sheet but they haven't revised it if there are any changes for 2024.  They don't even have the numbers for the kits for the new style interior.

 

UI-Bulletin-153d.pdf (gmupfitter.com)

 

 

 

 

[Doug Krussel]

The kit is identical, except the switches are on the right side now under the infotainment area.

My real only issue is trying to find the best way through the firewall since no entry nipple seems to exist in the 2024 HD model.

[Dr1ft3r]

On 5/22/2023 at 7:49 AM, gemarsh said:

He is asking for a '24, he said he looked for the older dash location for the pass thru, evidently gm changed that also.

 

Fair enough. I thought it may be irrelevant, but I linked it just in case. One would think that GM would include instructions on how to install this.

[TJP249]

Doug, did you ever figure this out?  I'm in the same boat.  Still nothing updated on GM Body Builder website.

 

My guess is at the bottom of the wiring passthrough in this picture.

 

If you have the full kit in a bag, can you send me the part numbers of the individual pieces, most importantly the actual switch bezel?  I am actually installing mine in an aftermarket center console.  Figured I would just order the existing parts from a 23, but the bezel around the switch module is contoured for the left-hand knee panel and won't sit correctly on a flat surface.  Hoping the 24 version will work better.

 

Thanks,

 

Tom

[Doug Krussel]

I believe you are correct, I pocked this location with a glow rod and it did appear to have a rubber seal...so that must be the passthrough.  

Regarding the part numbers.  The kit is identical to the 2023 with the exception of the switch bank like you suggest.

[Doug Krussel]

The switch bank on mine was already installed in the bottom center of the cab below all the air conditioning controls.

I don't have the part number but it is flat which should help you with what you are trying to accomplish.  

[TJP249]

42 minutes ago, Doug Krussel said:

The switch bank on mine was already installed in the bottom center of the cab below all the air conditioning controls.

I don't have the part number but it is flat which should help you with what you are trying to accomplish.  

That's interesting.  Did they also mount the fuse/relay panel under the dash?   Or did they just leave the connector that goes to the switches unterminated under the dash?  They should install the whole kit at the factory like Ford does.

 

Tom

[Doug Krussel]

Chevy does not install the upfitter auxiliary switche wiring...literally just the 5 Auxillary switches and they give you the rest of the parts when the vehicle is delivered.  It's been a little bit time consuming but easy to do.

Yes, the switch back has a connector that plugs into the kit supplied.  They also run the 5th wire to the third brake light arae if you run a strobe light or anythng like that.

[TJP249]

Understood,  I thought they didn't install the switch panel in the 23's and earlier, so was curious if anything else changed.  I have all of the upfitter bulletins for the 9L7 as well as the snowplow prep w/roof wiring.

[Doug Krussel]

If you pay for the upgrade when you order a new truck they come with the auxiliary switches installed...but don't install the engine bay stuff or the behind the dash fuse block.  It must comes in a couple of bags in the truck. 

[TJP249]

On 5/29/2023 at 12:59 PM, Doug Krussel said:

I believe you are correct, I pocked this location with a glow rod and it did appear to have a rubber seal...so that must be the passthrough.  

Regarding the part numbers.  The kit is identical to the 2023 with the exception of the switch bank like you suggest.

 

So actually none of the part numbers line up from the 23's to the 24's

 

Stopped by a local dealer who had a 24 in stock with 9L7 and was able to get part numbers off each component.  Should have seen his face when i pried the switch bank out of the dash!

 

New part numbers: 

 

87866808  - Switch bank-Black  (Would be different for other interior colors.  Not showing as available on GM parts

 

84810191 -  Power harness   About 36.00   Not sure what has changed on this part.  Should have taken my 23 cable for comparison

 

86812139 -  Fuse/Relay panel assembly  About 100.00     Has a longer cable to switch bank as the switch location has changed