Custom buttons in empty dash spots

[Matthew Jeschke]

I'm not entirely sure how this hooks up. If it utilizes a relay under the driver's side knee bolster?

It makes use of one or both of the SEO 1 & 2 fuses in the under hood fuse block.

 

[Matthew Jeschke]

Here's more info I found in another location / snow plow hookup guide. It shows how to hookup the cables from the factory for Aux Light. Of course my truck didn't have the snow plow option lol... So am retrofitting as best I can to use for lightbar.

Not sure where relay is? Assuming it's the SEO relay under the knee bolster, but that appears to be designated for multiple circuts?

Quoted from Guide:

Emergency Roof-Mounted Lamp Switch This provision includes a dash-mounted switch (see Figure 1), a relay, and wiring which is routed
up along the Left Hand B pillar that terminates at the roof as coiled blunt cut wires (see Figure 2). There are two blunt cut 12-gauge (3.0 mm2
)
wires, one is Brown (roof-mounted lamp power), it is controlled by the dash-mounted switch through the relay, the other is Black (ground).
The Brown power wire is protected by the 30-Amp SEO 2 fuse which is located in the Underhood Electrical Center

 

[Matthew Jeschke]

This has been a painfully slow process. I'm working on it bit by bit between work and everything else.

I found access to the SEO 2 power. It's in the "Bussed Electrical Center". It took a LOT of reverse engineering and searching to figure it out. Easiest thing would be if you EVER come across a HD truck with Roof Beacon button, then pull the whole circuit out at the junkyard should you like to do this.

The BEC has an unpopulated connection for SEO 2 - special equipment option 2 which is the roof beacon. I found the connector on eBay and ordered it it's part number 12193930 MBEC SEO Connector.

You could buy the empty delphi connector #12193930 and build it as well. It's linked below:

https://www.mouser.com/ProductDetail/Aptiv-formerly-Delphi/12193930?qs=xyz6lfZ1ktIvF0RTLD27Nw==

There were some images in the eBay ad that will be critical to wire this up. I'm saving them here for my reference and incase anybody else wants to do a factory "roof beacon" control for their light bars. I think these screenshots come from the electrical manual for the trucks. I have a copy of that should anybody like it as well.

Wish me luck I have to drill a hole in the roof and run electrical up to the roof rack once I got this all wired together.

 

[PG01]

Just saw this but yeah, ‘snow plow prep’ trucks (pickups, not suv’s) have the switch, wiring and blunt cut wires above the headliner..
Meh, better late than never.

 

[Rocket Man]

Way to go, doing it right.

 

[Matthew Jeschke]

thanks

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[Matthew Jeschke]

The adventure becomes even more exciting. The wiring would be a done deal BUUUUT I have a 2001 and cannot find the pinout for that connector. I'm trying to reverse engineer the schematic. Anybody have a MBEC (Mid Bussed Electrical Center) schematic for SEO connector on 2001 C/K Truck?

I found this for 2001 will prove useful but isn't the MBEC schematic

 

[Matthew Jeschke]

Much fun, reverse engineered what I could of SEO connector in Mid Bussed Electrical Center for my 2001 Tahoe:

Pin A - Always Hot Fused 30A from SEO2 in under hood relay center
Pin B - Not Connected
Pin C - Ground
Pin D - (FUSED??) Hot in Run & Accessory
Pin E - (FUSED??) Hot in Run
Pin F - Always Hot Fused 15A from SEO1 in under hood relay center

Assuming D & E are fused through ignition circuit somehow? I'm not too familiar with that.

Additionally, above diagram confuses me a bit. Surprised a 15A fuse is needed to run a relay?

 

[PG01]

I have to look, i used them when i put a plow on my ‘01.......years ago.

 

[Matthew Jeschke]

awesome, I fot everything rough wired in, minus the dash illumination for my button. Not sure where to best tap into that at.

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