New tow setup.... (Roadmaster/Demco)

[BruceMc]

I'm in the process of setting up a new toad, so I thought I'd post the setup. I'll add pictures of the install at a later date, and any tidbits that others may find useful. Likewise, I'll learn lots of new things via the conversations!

I have:
Tow vehicle: 2016 Sunseeker 2250 on Chevy 4500(combined brake/turn lamps)
Toad: 2012 GMC Canyon 4wd crew cab (separate brake/turn lamps)
Baseplates: Roadmaster
Towbar: Roadmaster Falcon 2
Supplemental Braking System (SBS): Demco Stay-in-play
Tail/stop wiring via diodes.

I've completed the baseplate install and brackets for the crossbar on the Falcon. All is very easy to install though it takes time. Only one 1/2" hole is need to be drilled in each side of the frame rails, otherwise the installation uses existing holes. The splash guard needed minor modifications to clear the bracket at the guard forward attachment points, and the air dam needed 2" square holes for the removable brackets.

The SBS is about 50% installed - I have the underhood unit installed and hoses/wiring routed to the hook-up location. The vacuum connection is complete. I have the location for the controller set up; it took some fabrication to build a bracket for the controller & deflect the heater duct.

I've installed the 6 pin input umbilical socket and wiring past the hookup location for the SBS, and on to the rear. Likewise, the breakaway switch is mounted and wires routed under the hood ready for hookup.
The wiring for the tail & brake lamps is complete and functional, except two items:
1) License plate lamp
2) Center High Mounted Stop Lamp (CHMSL)

The wiring in the Canyon is interesting. Both license plate lamps are wired individually, and are each routed through connectors back to the main bundle under the bed. Whether both are routed up to the distribution block or are combined at the first breakout under the bed, I do not yet know. However, as they have a common source, I'll bind both souces at the input of the diode pair, then tie both drains (feeding the lamps) to the output. The other diode input will be the tow vehicle input.

I've searched for the best method to wire in the CHMSL; there seems to be devices available to run the lamp from combined brake/turn, but many folks report issues with both versions - a 3 wire adapter or the 6 wire adapter.

More later....

[dodge_guy]

Thanks for sharing! Looks good.

[BruceMc]

The rest of the story:

Installing the braking system took time, and a bit of rework here and there. I mounted the operating unit under the hood in a convenient location between the air filter box and windshield washer & antifreeze overflow containers on the passenger side. The two hoses and electrical harness routing was easy & clean, along the top of the firewall to the drivers side.

The tail/brake light wiring + brake-away wiring was mounted in the license plate bracket with additional bracing, and routed to the radiator core support, where they terminated in connectors to facilitate easy bumper removal in the future, should it ever be necessary. From there, the cabling was routed to the battery breakout box/on to the connection point for the braking system, and aft to the tail/brake/CHMSL (center high mounted stop lamp) lamps.
As it worked out, I used 6 diodes, though during the setup for the CHMSL, I found the wiring bundle just before all was broken out for separate bulbs. All told, I could have done the setup with 4 diodes - Stop/CHMSL, Left turn/stop, right turn/stop, and all tail lights.

The Canyon is super easy to put into tow mode:
1) Hook up tow bar, umbilical, break-away cable, safety cables.
2) Turn on braking system via a switch on the Demco Stay-in-play "G-Force Controller" box.
3) Place the Canyon transmission in neutral, keep foot on brake, press & hold 2H and 4L buttons for about 15 seconds. When the red N light comes on, Put it in park, pull the key and hop out.

We tested the setup with a 20 mile run, including turn tests in a parking lot. The 2250 Sunseeker on Chevy has a tight turning radius, so with the motorhome steering wheel turned to the stops (full steering wheel lock), I turned about 220 degrees before my friend started holler... I had a half inch between bumpers.

[Y-Guy]

Thanks for sharing!

[BruceMc]

Pictures & comments of the install and tests...

Regarding the CHMSL, I found a blue wire in the MH harness for that line. I added it to the harness running to the trailer elec connector's center pin, and routed it via the last open lead in the 6 wire umbilical. It would have been nice if Roadmaster included a full 7 wire umbilical, but as their kit terminated the umbilical in a 6 pin connector, I can see where they felt the 7th wire would never be used.

Thus, I now have the standard signal and turn on the lower two tail/brake lights, and full brake lights/CHMSL on the upper two tail/brake lights plus the center high mounted stop light.