Trailer wiring

[jello_jeep]

I notice on my bus, there appear to be two trailer connections. One is a typical 6 pin round connector, the other one is a rectangular horizontally mounted connector that traces back to a junction box in the engine compartment marked Prevost tow package relays.

I am not sure where the 6pin wiring goes.

I am not familiar with the rectangular connection? I am going to tow a Jeep, and not sure if there is some reason to use that connection instead of the 6 pin or not?

Also does anyone know if the 6 pin is wired through all those relays too? :confused:

[Jon Wehrenberg]

Borrow that meter from your wife and check for power at the trailer plugs.

You gotta use those tools.

[truk4u]

Jeep,

The 6 pin is your trailer plug and not sure what the other is for. Mine also has the rectangle box, but I didn't think is was a plug.

[Kevin Erion]

I think Marathon installs the funny looking plug, I have never seen the other end on any trailer. I removed it and installed a 9 pin for my trailer, it had all the wires needed going back into the box over the motor.
Kevin

[bluevost]

Jeep,

You can get an adaptor to go from 6 round to 4 flat to wire up your jeep. You might also need some diodes to put in your jeep wiring to keep the voltage going to the lights only and not returning to the bus. Before I found out about these diodes, I was having fits trying to wire up my jeep to the bus.

Good luck and happy new year,

[Jon Wehrenberg]

" I Love Hummers, they taste like CHICKEN "

There, there....be a good little boy....

BTW Jeeps do require diodes because without them you will get feedback of voltage to other lights.

JPJ advocates adding a second set of bulbs dedicated exclusively to use while towing, not a bad idea, and Mango set of magnetic lights is also an easy way to get the job done.

[jello_jeep]

Thanks for all the good thoughts and ideas gang!

Much appreciated..

Couldn't get the hang of that Prevost plug!

[jack14r]

I asked someone at marathon in Florida what is the rectangular plug and he said it is a european trailer plug.Marathon on the 6 pin does not comply with the national trailer wiring diagram,use your meter to verify the correct pins you need.

[Jon Wehrenberg]

Warren,

On both coaches I had to verify the trailer connectors were wired as required. Just use that VOM and see what pins have power when various lights are on like turn signals and parking lights.

You need to know before you start to set up the toad because some are wired for combination brake and turn signal and some are wired for separate brake and turn signal.

[jello_jeep]

I will check it. I just could see that the one Prevost plug was diretctly wired into that box, and had never seen a connector like that before. Not being a trailer expert, I just wasn't sure if I was going to be missing something by not using the rectangular plug. Now I see that I won't !

Is the point of all the relays to be able to power the trailer lighting system from a source seperate from the bus? I had never seen relays used in a trailer system before. I reiterate here that trailer wiring is not my forte :rolleyes:

[Jon Wehrenberg]

I have not taken the time to look at the trailer wiring set up I now have because it is working but I can tell you that on the old coach the relays had their coils connected to their respective light circuits and each relay had a single function, like brakes or LH turn signals.

The actual voltage to the toad lights then came from the 12V post in the big junction box, through the NO relay contacts to the plug. When a bus light was energized, such as the brake lights, the coil on the relay would close the contacts and energize the plug pin for that function.

It was a real simple system, and with the exception of a small load on the light circuit for the relay coil no lighting loads for the toad were carried by the bus lighting circuits. I guess the reason was so the amount of lights on the toad or trailer would not overload the circuit breakers for the bus lights.

[jello_jeep]

Makes perfect sense Jon...

Thanks!