Third Brake Light on 2016 JGC Toad

[w6pea]

I have a 2016 JGC Overland. I installed a Road Master EZ5 Baseplate. I also have the RoadMaster Nighthawk tow bar. Also, we installed an SMI Duo Play and Stay Brake system.
My question is when we step on the brake in the tow vehicle only the Left/Righ illuminate. When we step on the brake pedal in the JGC all three of the brake lights illuminate. When we turn on the headlights in the tow vehicle only the rear tail lights on the JGC Toad no side marker lights is this correct or did we not wire something.
Otherwise, it seems to work perfectly Now to take the RV over and make sure the Tow set up on the RV is wired correctly.

[LJowdy]

You're wired correctly. It's a very difficult thing to make the 3rd brake light illuminate with the stop lights. The side markers are something that can be done but hardly anyone spends the time and money to make that happen

ps. It took a while to figure out that JGC was Jeep Grand Cherokee

[FIRE UP]

Originally Posted by w6pea

I have a 2016 JGC Overland. I installed a Road Master EZ5 Baseplate. I also have the RoadMaster Nighthawk tow bar. Also, we installed an SMI Duo Play and Stay Brake system.
My question is when we step on the brake in the tow vehicle only the Left/Righ illuminate. When we step on the brake pedal in the JGC all three of the brake lights illuminate. When we turn on the headlights in the tow vehicle only the rear tail lights on the JGC Toad no side marker lights is this correct or did we not wire something.
Otherwise, it seems to work perfectly Now to take the RV over and make sure the Tow set up on the RV is wired correctly.

w6pea,
The third brake light or otherwise known as the "CHMSL" or, Chassis High Mount Stop Light, as it's labeled in the tech world, (and is labeled as such in your fuse section of the owners manual) is activated by a completely separate circuit, in your G/C. It's like that in ALL VEHICLES that have one. And that includes cars, trucks, motor homes, etc. When a toad, such as your Grand, is wired with any form of aftermarket tow harness, that harness is tied into the tail lights only, not the circuit that the third brake light operates on.

The aftermarket harness, or, even for us folks that create our own harness, simply get's directly tied to the turn/brake light filaments in each tail light. As has been stated, not many take the time set to set up the operations for the third brake light. A totally separate wire would have to be integrated in the trailer plug of the Tow vehicle. And on some plugs, there's not enough pins. Then, that would have to be incorporated into the pig tail and finally, to be set up in the toad.

It's not worth it. To have good, properly working regular brake lights when towing, is all that's needed. Hope this helps some.
Scott

[Crabby Mike]

And remember that the point of the third light, when it was first mandated, was to increase visibility of your brake lights to vehicles behind you. Since when you're towing the car, there's another (and bigger) set of brake lights above it (as seen from behind), that third light on the car is inconsequential.

[Healeyman]

W6,

An old whiskey zero here.

Regarding the 3rd brake light, on BOTH of my toweds, I installed a light pulsing module ($7 Amazon https://www.amazon.com/Qiorange-Stro...flasher+module) in the feed line. It pulses ONLY the 3rd light, 3 times fast, 3 times slow, then is steady.

My cars do not use the orange turn or marker lights. The Red is used for brake and turn. The fender mounted lights are always steady.

I wired 2 SPDT relays, one is pulled in by each red stop/brake light. When only one relay is pulled in (as with a turn), the 3rd brake light does not come on.

When both relays are pulled in (as with braking) 12VDC passes through the closed contacts of each relay, wired in series, to the flasher module + in line before the light.

It works like a charm and really lets followers know that I am stopping.

73s,

Tim