We have our 2012 Jeep Grand Cherokee ready to tow. . .
We prefer to wire tow car tail, turn & brake light bulbs to motorhome which require diodes to keep motorhome and tow car power isolated.
In the past, we cut tow car rear tail lamp wires soldering 3 quick-disconnect terminals on the ends and used 1 Roadmaster 3-terminal diode for each light bulb. This could be 9 terminals on each side, 18 in total and something that had to be dealt with when not using the tow car behind a motorhome any more.
We found a super new device called Tow Daddy that greatly simplifies connecting motorhome to tow car tail lights. Tow Daddy - The Best Designed RV Products on the Planet (http://towdaddy.com/)
On our new Jeep, with TowDaddy, we did not cut any wires. We just unplugged Jeep cable from our tail light and plugged it into Tow Daddy, then plugged Tow Daddy into the tail light.
We installed a Blue Ox baseplate and here are some other tow car stuff we did to our Jeep:
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We made a tow brake using a Bimba 096-P air cylinder
And a car specific floor bracket for our tow brake from Roadmaster:
Roadmaster Inc. - Tow Bars, Braking Systems & RV Accessories (http://roadmasterinc.com/products/braking/seatadaptor/seat_adaptor.html)
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To know when brake pedal is being pushed we are adding a 2nd Jeep brake pedal switch from Roadmaster:
Roadmaster Inc. - Tow Bars, Braking Systems & RV Accessories (http://roadmasterinc.com/products/braking/stoplight_switch.html)
Running a wire from the new Jeep brake switch to a motorhome dash LED will let us know tow brake is working
and more important let us know if Jeep brake are being activated when they should be off.
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If tow car has combined brake & turn lamps AND the tow car brake lights turn on when tow car brake pedal is pressed WHEN ignition is off, there is a problem.
Motorhome turn signal will turn on tow car turn signal lamp, but if tow brake is activated, it will cause turn signal to stop flashing.
A relay is needed to turn off tow car brake lamp when towing.
Roadmaster has a common relay and an explanation of the problem:
Roadmaster Inc. - Tow Bars, Braking Systems & RV Accessories (http://roadmasterinc.com/products/braking/brake_light_relay.html)
Tow Daddy also has a built-in brake relay and brake switch to prevent turn & brake confilct and it can notify us in motorhome if brake pedal is pushed.
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