AUX pass-thru wiring.

[KnuckleHead]

mine is a '19, yes

Did you just buy the parts from the dealer, or is there someplace putting together a kit?

 

[elephantrider]

I bought a kit from a guy on fb. I thought he was on here but not sure.

 

[Brutal_HO]

Thank you. Just pull it out? I did try to both push and pull it as if it were a locking tab. I'll give it another try.

Are you removing the PDC cover to access it? Much easier to see/unclip.

 

[foneguy]

what is the end result of all this work?

 

[StormTrooper3500]

Hate to bump this older thread, but can someone post the part numbers for everything needed? I can find the panel, but nothing else

 

[Wpg_Ram]

Hate to bump this older thread, but can someone post the part numbers for everything needed? I can find the panel, but nothing else

That’s pretty much the only parts available
...

You’ll need an interface cable, the OBD programmer, aftermarket fuse block (the ones you’ll find with Mopar part #s are either for a cover or a bracket or “wiring” which isn’t the fuse / relay box itself and is a waste of money) ... the wiring from the switch to the fuse block there is a member on here, can’t remember who, you need to review the posts, who makes a “kit” that will work.

so what you have to do:

1) get the switch bank

2) either make your own wiring or track down the member and DM them (if you can’t find them on this one, theyre also on the ForumZ site) for the “oem to fuse block wiring”

3) get the aftermarket relay / fuse block

4) get the OBD software, plug, wiring

5) figure out wiring from the block to your auxiliary stuff

6) install / swear as needed

Source: I ordered everything I could for fuse / relay box from the dealership (and sent it all back for being wrong) and it was all the wrong parts even though the descriptions were different and said it was right . .. haven’t found a relax box in the wrecker so went with an Amazon one ... will be doing the swearing when the weather warms up

 

[thestuarts]

Last year, I was working on a video that explains how to utilize the AUX switches and AUX fuses. I had to stop editing the video to help a family member, so it isn't finished, but here is a preview of the video. Thanks to @Brutal_HO, @IronByron, and @Jimmy07 for the information that enabled this video.

Please let me know if anything in the video needs clarification.

Here is a PDF document that explains the AUX switches. The document is not 100% finished, so let me know if you have any feedback.

AUX Wiring Examples.pdf

drive.google.com

 

[Brutal_HO]

Great job! Very nice video. Thorough, clear, concise. Doc looking good. The effort shows.

 

[wyleam1066]

Any

Last year, I was working on a video that explains how to utilize the AUX switches and AUX fuses. I had to stop editing the video to help a family member, so it isn't finished, but here is a preview of the video. Thanks to @Brutal_HO, @IronByron, and @Jimmy07 for the information that enabled this video.

Please let me know if anything in the video needs clarification.

Here is a PDF document that explains the AUX switches. The document is not 100% finished, so let me know if you have any feedback.

AUX Wiring Examples.pdf

drive.google.com

Great video and document. What if my truck didn't come with the Aux pdc?

 

[Brutal_HO]

Any

Great video and document. What if my truck didn't come with the Aux pdc?

There's a couple threads here about adding the OEM switches and enabling it using AlfaOBD, but the AUX PDC & wiring would be aftermarket. Many are skipping the OEM switches and using the Switch Pro.

 

[wyleam1066]

There's a couple threads here about adding the OEM switches and enabling it using AlfaOBD, but the AUX PDC & wiring would be aftermarket. Many are skipping the OEM switches and using the Switch Pro.

Thanks. I did install the aux switches and got the alphaobd before I realized what a pain it is to put in the oem aux pdc. So, I ordered an aftermarket wired fuse and relay box and wonder if I can connect that to the enabled aux switches. I tinker a bit and did this with an aftermarket switchbank on my last truck, but that was easy. Is there a pinout sheet, that is easy to read for non electricians, anywhere in these forums?

 

[dieselbeef]

im just running my fogs and rev lights hot off the battery to relays and mounted after market sw under the dash...old school stuff i guess. im afraid to mess witha ll the new wiring and electronics on these new trucks....

 

[SFAngus]

Thanks for posting this... super helpful. I was about 80% of the way there, and this clarified the last few questions that I had.

However, I just opened up my wiring kit for the first time, and now I have a new question. In all the photos and videos that I've seen, position two on the grey upfitter jumper plug is vacant... however mine has a blunt cut wire in that position. (Grey with a beige Stripe).

Does anyone know what that wire is for?

 

[thestuarts]

Thanks for posting this... super helpful. I was about 80% of the way there, and this clarified the last few questions that I had.

However, I just opened up my wiring kit for the first time, and now I have a new question. In all the photos and videos that I've seen, position two on the grey upfitter jumper plug is vacant... however mine has a blunt cut wire in that position. (Grey with a blue(?) Stripe).

Does anyone know what that wire i

What year and model truck is it?

 

[Brutal_HO]

It's just listed as a "Dash PassThru" along with 3 of the same (4 5 circuits total) coming from the "White upfitter jumper" (new for 2021).

Looks like they terminate at the firewall somewhere under the hood (by the AUX connectors?).

So those that asked for more pass-thru circuits, looks like you have plenty now.

ETA: There's a 5th pass-through circuit. They snuck another wire (W550) into the original upfitter jumper on pin 2.​

https://www.ramtrucks.com/BodyBuilder/service/Image?imageId=MtQrP%2FFqLY5r%2Fest8MtGjGgHzAHGUTU0WB3rWuqSY7YmQ2vEhuBWBJy4XObqxE4%2F%0A

2021:


-----------------------------------------------------------------------------------------------------------------------------------------
-------------------------------------------------- no connection here, just images ---------------------------------------------------
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2020:

 

[SFAngus]

What year and model truck is it?

2021 Limited Longhorn 3500.

 

[SFAngus]

It's just listed as a "Dash PasstTru" along with 3 of the same (4 circuits total) coming from the "White upfitter jumper" (new for 2021).

Looks like they terminate at the firewall somewhere under the hood.

So those that asked for more pass-thru circuits, looks like you have plenty now.

https://www.ramtrucks.com/BodyBuilder/service/Image?imageId=MtQrP%2FFqLY5r%2Fest8MtGjGgHzAHGUTU0WB3rWuqSY7YmQ2vEhuBWBJy4XObqxE4%2F%0A

You guys are fast.

Thanks, I just realized that I've been relying on the 2019 schematic because that's what's on most of the posts here. I just did a quick search and found the updated 2021 schematic, which shows that new wire (W550).




At first I was thinking that the engineers had resolved the complaint about only one AUX being able to route back into the cab, but looking at the under hood setup, nothing has changed. (EDIT- they did fix it, I'm slow).

 

[Brutal_HO]

You guys are fast.

Thanks, I just realized that I've been relying on the 2019 schematic because that's what's on most of the posts here. I just did a quick search and found the updated 2021 schematic, which shows that new wire (W550).

View attachment 14421


At first I was thinking that the engineers had resolved the complaint about only one AUX being able to route back into the cab, but looking at the under hood setup, nothing has changed, so I can't figure out what that W550 wire connects to.

Look at my edited post. There should be FOUR new pass-thru wires. Probably just blunt cut taped up in a bundle.

 

[John Jensen]

Interesting. On my 2020 3500 HO that port #2 is blank. My wiring diagrams do not show a port #2, meaning no wire there.
I'm no help but interested in what you find out.

 

[SFAngus]

Interesting. On my 2020 3500 HO that port #2 is blank. My wiring diagrams do not show a port #2, meaning no wire there.
I'm no help but interested in what you find out.

Yeah, it looks like this all changed for 2021.