Upfitter Aux Panel Install "Plan" Switch 84347196

AlaskanMooseMan · April 14, 2022

Hey all,

Hoping to upgrade my switch - From just 'Traction Control' and 'Cargo Lights' to the upfitter switch 84347196 that has those two switches plus 4 aux switches (pic 1). There is a pretty extensive thread on this already but it is long and jumbled with no clear summary, I am also no expert on any of this so hard to understand half of it! So hoping to run my plan by y'all and see if you think this will work.

2018 Silverado 2500HD 6.0L

Parts:

Aux Switch Part #84347196

(4) Pre-Terminated Leads - Available from HarnessDr (pic 2)

4 Relay Panel with Flyback Diodes (mgispeedware.com/product/automotive-relay-panel-spst-on-sale/) (pic 3)

Plan:

1. Remove existing "Traction Control" and "Cargo Lights" switch. Remove two harnesses from back of the old switch.

2. Take the four pre-terminated leads and insert into the larger harness, spots 10, 11, 12, 13 (currently empty because truck did not come with upfitter switch). You will have to pop the harness latch off to do this (pic 5).

3. Extend off the 4 leads I just installed and run them all the way up to relay location.

4. Install relay bank including mounting and running power and ground wires for the relay bank.

5. Connect the signal leads from the aux switch to each individual relay. Key is to make sure setup as a "ground trigger" on the relay as these switch wires do not have positive voltage (pic 4). Setup like load 1 and 2 in pic 4..

6. Run power to the intended accessories from the relay, good to go!

Couple of questions. Is this the right relay setup for ground switching?

Will these wires work as ground switches?

Also, in the big thread on this there was mention of using diodes to prevent damage to the aux switch. I've never wired a diode into automotive wiring but if that works please let me know a good part #. I'm also not sure what direction the diode would need to point as it is a ground trigger. I ordered the relay panel with "flyback diodes" thinking it will accomplish protecting the switch, but not 100% sure that is the right setup to protect a ground trigger...

Thank you to anyone who read this whole thing and thanks in advance for any input!

Edited April 15, 2022 by AlaskanMooseMan
picture order, remove redundant, question

AlaskanMooseMan · May 3, 2022

So got this all setup as described above, relay wiring was as follows (see picture):

30: Fused 110A 12v+

86: Fused 5A 12v+

87: 12v+ power ran to lightbar (light bar grounded to chassis)

85: Ground trigger ran from back of aux switch panel

Once everything was setup and powered, it worked! The aux switch turned on the light bar! For about two minutes, then everything quite working. The aux switch would no longer engage anything (traction control and cargo light buttons still worked though)

My thinking is even though the ground trigger was on the low current side of the relay, it was too much for that switch or BCM to be the ground for that relay? I know the relay is still good, because if I manually ground 85 in the configuration above it turns on the light and works as it should.

Stuck with two options. 1. Just use regular aftermarket switches and go back to the old panel with traction control and cargo lights only. Or 2. order another 4 aux switch and try again. I am wondering if there is such a thing as a even smaller relay I can use the ground trigger to engage the lights relay?

Anyways, didn't want anyone to go and try this thinking it would work so hopefully this stops someone from trying this as is. If anyone has any advice I am all ears.

Thanks

RenoGuy · October 18

I was gonna install this on my chevy silverado 1500 2015

i almost purchased the aux panel and the hardness from harnessDr and the pre terminated wires, then i saw your post.

harnessDr make a harness that plugs into the aux box under the emergency break, and seen few videos where it shows nothing about a relay box, whaat was that for ?

So if i install the aux panel and run the pre terminated wires straight to the pins in that aux box behind the emergency break it wont work ?