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Yak61

Auxiliary Power For Supplemental Brake

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I have a 2005 Fleetwood Jamboree on the Ford chassis. I am trying to obtain power from the MH 7 way plug for a supplemental brake. The lights work, but I have no power to the two prongs that I thought should supply 12v power at the plug. Are these circuits normally left disconnected? Any idea where the connection point would be?

Mike

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Mike,

Welcome to the Forum.

If you are talking about your controller for your supplemental brake. the answer would be no. The manufacturer doesn't know what kind of supplemental brake you would be using. I would wager that if you look at the back side of your 7 way plug you will find that it is only wired for lights just the same as my pick up.

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Can you tell us what kind of supplemental system your thinking about.

That will give everybody a chance to suggest where to get the 12 volts.

Rich.

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It is a Brake Buddy. I have installed a separate cigarette lighter plug in the toad. I open the back of the plug on the MH and Herman you are correct they just have the lights, Brown, Yellow and Green and Black on the 7:30 prong (I assume ground) but there is one red 6" wire on the 4:30 prong.

On "Roadmaster's web site they show the 4:30 location for brakes ( I believe for a brake control rather than constant 12v power) I think the power should go to the center pin or the 1:30 prong for auxiliary power. Any thoughts?

Mike

http://www.roadmaste.../85-4041-01.pdf

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Mike,

Thanks for the update.

Using the information from the web link you listed. The number 2 pin(Black Aux) could be used to feed 12 volts to the brake system, or be used to keep the battery charged so as you use up power it is being replaced. Make a note so anyone working with this change is aware and the reason. Service Centers do Not Like Surprises ! It kind of goes What The $&^%***)(

By placing a diode in the line or right at the battery, with the banded end connected to the positive terminal would allow power to flow to the battery. It also will act as a(one way valve) it will not allow power to flow back to the 6 pin Toad connection.

Typically, a 6 amp diode, rated at 50 volts will work just fine. The wire gauge should be # 8 or # 10. The longer the run the heaver the gauge wire required.

You did mention a connector to the cigarette lighter. Are you using this to power the braking system?

The braking power could come directly from the coach, but if you loose the connection for some reason then (No Brake System) the the circuit powering the battery. Even if the circuit is lost between the coach and toad you would still have braking for the toad. Should the fuse blow for some reason, then your back to a no brake situation.

ONE other thing if you are just powering the aux braking system then you could use a lighter gauge wire-- say a # 12 gauge. Still use the Diode!

Hope this helps.

Rich.

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Actually, I MUCH prefer to wire a toad battery charge line as follows:

Coach chassis or coach battery positive (whichever battery is closer to the back of the coach) to 30 amp in-line fuse as close to the battery as possible to one large lug of a 40 amp constant duty relay with 8 gauge wire.

Other large lug of relay to 4/6/7 way connector at back of coach and on to coach to toad wiring harness.

If two small terminals on relay: negative to chassis ground, the hot/positive to any IGNITION ON source (hot only when ignition on).

If only one small terminal (relay grounds through its mounting bolts to metal): to any IGNITION ON source (hot only when ignition on).

From toad wiring harness to toad battery positive with 8 gauge wire with fuse as close to the toad battery as possible.

The two fuses are critical, as both battery positives are HOT and could be a dead short if they contact ground.

Also, run an 8 gauge ground wire from toad negative battery terminal to wiring harness to good, clean chassis ground on coach.

Brett

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You might want to check with either Ford or Fleetwood. I don't know about the bare chassis supplied to coach makers but when I bought my last two Chevrolet diesels that came wired for towing with a 7 pin, the "hot" wire was not connected, and the battery of my 5th wheel was not being charged. In the earlier 2005 truck I had, I had to install a missing fuse, in the newer 3500 Silverado it was just a mater of connecting a wire...

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