Towing connecter

[Yankee802]

When I hooked up my toad for the first time to test it, none of the lights worked. I put a voltmeter to the pins and got nothing. What should I check next? It looks like the wire loom terminates in the box above the engine, where you can start the engine, should I look there? Are there any fuses I should check, and if so where are they?

Geoff

[gmcbuffalo]

What are you using for a ground? Most of my tow light problems are usually a bad ground.
GregM

[Yankee802]

I'm not sure, I assumed the ground wire was in the loom that went into the box above the engine, I haven't opened that up yet.

[Jon Wehrenberg]

Checking at the pins on the plug should have produced some indication of power.

If your tester is connected to a good ground and the pins do not yield any voltage indication at all start following the wires. (I am assuming you had the bus lights on and the flashers and the brakes engaged so the lights lit up)

Your bus lighting is 24Volt so typically the way the converters brought 12 volt power to the pins on the plug was to use a relay with a 24 volt coil which was powered by the specific light function of the bus to open and close contacts which were powered off the 12 volt post in the electrical box.

I cannot imagine a failure of every relay, so as you follow the wiring back to the relays the problem may be as simple as the power from the 12 volt post may not be getting to the relays.

There is no shortcut. You have to start at the plug (take it apart and make sure you have continuity at every step) and work your way back. The good news is 100% of the wiring and components are going to be right there at the back of the bus and in or around the big electrical box.

[HarborBus]

Yes, start at the box above the engine, mine is on the firewall behind the air cleaner. Everything is color coded. Put your tester on the individual pins and confirm all lights then see if the corresponding wire colors are in the plug and test them. Like Jon says there are no short cuts you just have to go back until you get power then work forward or visa verse.

[Joe Cannarozzi]

Where have you been Yank? Find yourself a different campground?

[Jerry Winchester]

I have to think a Marathon that old didn't have the master switch for the tow package, but that is where I usually end up.

[JIM CHALOUPKA]

I believe the trailer wiring is of Prevost origin, if that is true is there wiring provided to the drivers area for a brake controller?

My bus has a 10,000# Prevost hitch. Is the 20,000# hitch a simple exchange?

To install the 20,000# unit would one simply remove the old and install the new in the same place (bolt holes) with similarly shaped and more robust components, or is it more complicated than that?

JIM

[Kevin Erion]

Jim,
I changed the hitch on my 99 Marathon, 98 shell. You have to change the engine cradle also. It took me about 8 hours to do the job, there is also some welding involved.

[Toy Box]

No, Jim, you have to buy and install a new engine cradle. I got mine from Prevost Jax.

[JIM CHALOUPKA]

That sounds :eek:, and like something I will put at the very bottom of the list.

Thanks for the feedback.

JIM

[Yankee802]

Ok, guess I'll have to make time to do the investigative legwork and will probably start at the box and work to the plug. I assume this was installed by Prevost or at least Marathon. I'll also shoot an email to the previous owner to see if he ever towed anything with the coach. When testing the pins, the coach was running and I did have the emergency flashers on to try to get something on any of the pins.

Joe: I've spent the last year at the Virginia Beach KOA, been very busy this summer. I just put in my 2 week notice and will be going back to the base campground at Oceana next month.

[hhoppe]

Geof: When I got my first 89 Royale Prevost I experianced the same thing. We found the 24V to 12V relays hidden in the driver side rear closet below and to the right of it. It takes a midget to even get close enough to see them. As it turned out they were wired wrong and had to be re-wired to make the female plug at the bumper work with the coach lights. After you get that plug working your next task is to mate it to your jeep lights. There is a couple of ways to accomplish this. Camping world has setups to do it a couple of ways. I found the easiest way was to run trailer light wires from the male connector to the back of my envoy and drill the tail light housings and install bulb sockets on each side. Install two element bulbs in the sockets and you have tail, turn and stop lights without interfering with you tow vehicle light system. First open you tail light lens to make sure your housings have room for the extra bulb. Try to get the aid of someone with electrical experiance to help you if you can. Good Luck

[Jon Wehrenberg]

I think it is a converter installed plug. I would start at the plug and work backwards. Hard to believe every pin is without power. I think you will find if that is the case that the 12V supply has an open circuit somewhere. Usually the connection point for the 12V supply is the post on the bottom of the electrical box slightly to the right of center. It should be marked on the diagram for the box. What will not be marked on the diagram for the box or terminal list is the trailer plug.

Since your coach is #1 all of this info and advice may be completely wrong because a lot of what we now take for granted and accept as common practice may not apply to your coach. All converters products have evolved based on what they ave learned over the years.

[JIM CHALOUPKA]

Well according to Kevin it takes a new engine cradle when one installs a 20,000# hitch.

Kevin did his own install, wow, very commendable, and it took 8 hrs!

Checked pricing on a 20,000# kit from Prevo today and they verified the need for a new engine cradle.

The kit part number is: 410805, priced at $1,368.97. Non stocking, made to order only @ 40 days lead time. (The factory is on two week shutdown now, so add that in)

They now have a policy of: The kit is not sold to anyone for a do it yourself installation.

Prevost must do the install, due to liability issues!

This will not be happening any time soon for me if ever.

Still gathering information on toads and trailers.

JIM