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Author Topic: Brake Controller and Engine Brake (2004 Beaver Marquis)  (Read 362 times)

Rick Vyncke

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Brake Controller and Engine Brake (2004 Beaver Marquis)
« on: July 12, 2019, 08:29:55 PM »
I want to tow a heavy boat on a triple axle trailer with electric over hydraulic brakes through the Rocky Mountains.  I towed a previous boat that had hydraulic brakes actuated by compression of the trailer tongue.  The new boat/trailer has electric over hydraulic which are far superior in almost every way.

I wish to tow that boat behind our 2004 Beaver Marquis which I believe has a 10,000lb hitch and towing capacity.  I plan on installing a Tekonsha Prodigy P3 brake controller in the Marquis.  This is the same controller that I use in our SUV which works great.

Here is my concern and hence the reason for this post...

The brakes on the trailer are activated by a combination of "brake lights on" and "the controller sensing deceleration"... the more deceleration the harder the brakes are applied.  This is a proportional brake controller.  When the engine brake is on... the brake lights are on.  That typically would not cause me any concern.  However, when towing down a steep mountain range, the engine brake will be on for long distances and I do not want to overheat the trailer brakes as a result of the controller applying them as a result of the engine brake being engaged.

I know I am not the only person wanting to tow a large trailer with electric brakes behind a Beaver Coach.  What have you done to address this issue?  Is it an issue?  Should I be concerned?  Is there a workaround?

Thank you in advance
Rick V
2004 Beaver Marquis, Garnet (3 slides)
43'
C12

Mike Shumack

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Re: Brake Controller and Engine Brake (2004 Beaver Marquis)
« Reply #1 on: July 12, 2019, 11:39:48 PM »
I was looking at the wiring diagram for 2004/05 Patriot Thunder, and it looks pretty easy to disable the brake light from coming on with the Engine Brake.
This is the wiring diagram (I copied/pasted two pages together to show the circuit).  Just disconnect the wire "204" at connect C6-8 (or at the Engine Brake Relay) and the brake lights will not come on with the Engine Brake but will still come on with Pedal.
Your Marquis wiring may be different. I'll try to look at that diagram too if I have it.

- Mike

'05 Beaver Patriot Thunder, Vicksburg, CAT C13  525HP, Allison 4000MH, HydraLift
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Steve Huber Co-Admin

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Re: Brake Controller and Engine Brake (2004 Beaver Marquis)
« Reply #2 on: July 13, 2019, 12:02:33 AM »
Mike,
Not sure it's a good idea to not alert drivers behind you that you are braking. I would caution not to disable the brake lights from the  engine brake. If you get rear-ended and they find that the brake lights have been disabled from the engine brake it could get expensive ……


Rick,
Consider mounting a micro switch on your tow bar that will close only when the trailer is pushing against the RV. You can use heavy duty double sided tape to mount it. Route the brake light signal through the micro switch. Then the trailer will only brake when it is decelerating and applying forward force to the RV, which is what you want.
I'd mount the switch on an AL plate and mount the plate to the tow bar so the switch is closed only when the towbar is being forced against the receiver. You may also want to tie into the switch output signal and run it to an indicator (LED) in the cockpit so you know if and when is is activated. Obviously this requires a slight bit of play between the tow bar and the receiver.
https://www.amazon.com/s?k=micro+switch+roller+lever&crid=1MHQEA6G202XJ&sprefix=micro+switch+%2Caps%2C189&ref=nb_sb_ss_i_3_13
Steve


Steve
2015-          07 Contessa Bayshore C9,  400 hp
2013-2015: 00 Marquis Tourmaline, C12, 425 hp
2005-2013: 01 Contessa Naples, 3126B, 330 hp

Bill Lampkin

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Re: Brake Controller and Engine Brake (2004 Beaver Marquis)
« Reply #3 on: July 13, 2019, 12:58:10 AM »
The micro switch idea is just like what happens with surge brakes on a boat trailer, the brakes would be on whenever the coach is decelerating, as when the jake brake is on. The fore-aft movement of a hitch over a ball is very small, less than 1/4" total is my guess.

Rick, your best bet may be to fine tune your Prodigy so that your brakes will come on when needed, but not before. Might take some trial and error, but you should be able to dial it in.

I've towed boat trailers with drum type surge brakes, then after switching to disc brakes (elect over hyd) on our previous 5ver, I put disc brakes and a new surge brake actuator on our boat (19' runabout, single axle). Very smooth.

I would swap out the drum brakes to disc on the  boat if you haven't already. I wouldn't worry about overheating disc brakes, at least I have yet to do that. By the way, the steepest grade we saw last summer in the Rockies was Teton Pass, near Jackson, at 10%. Jake brake pulled her down nicely!. I wasn't towing a triple axle boat, however.
2005 Patriot Thunder Lexington, 3 slides
40' tag axle (short wheelbase)
525 hp C13

Steve Huber Co-Admin

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Re: Brake Controller and Engine Brake (2004 Beaver Marquis)
« Reply #4 on: July 13, 2019, 01:58:09 AM »
Bill,
To clarify, the micro switch allows the trailer brake to come on when it is decelerating AND pushing against the RV. If the trailer brakes apply only upon deceleration, you will have a 2000 lb trailer trying to stop a 40000 lb RV. Good way to wear out the trailer brakes.
Steve
Steve
2015-          07 Contessa Bayshore C9,  400 hp
2013-2015: 00 Marquis Tourmaline, C12, 425 hp
2005-2013: 01 Contessa Naples, 3126B, 330 hp

Scott Shearer

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Re: Brake Controller and Engine Brake (2004 Beaver Marquis)
« Reply #5 on: July 13, 2019, 07:36:51 PM »
Rick,
Some coaches incorporate a diode to prevent the engine brake activated brake light signal from back-feeding to the brake light switch, you can use a test light to verify whether yours back-feeds or not. 

If it does back-feed, you can still tap into the output side of the brake light switch for the brake light signal, then install a diode downstream of the tap.

Here's a link to a diode. 
https://www.etrailer.com/Accessories-and-Parts/Roadmaster/RM-690.html
Scott

2006 Patriot Thunder
Lexington IV 40'
Cat C13
2015 JKU Hard Rock

Rick Vyncke

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Re: Brake Controller and Engine Brake (2004 Beaver Marquis)
« Reply #6 on: July 16, 2019, 03:48:47 AM »
Thank you for all of the suggestions.  Did I say it was a heavy boat?   About 8,000 lbs boat and trailer.  Trailer is triple axle with electric over hydraulic disc brakes.

Spoke with Beaver Coach sales and they tell me that I can connect a wire to the brake switch located on the firewall and where wire #106 is connected. Run that through shift tower (where ever that is) into the electrical bay.  Then connect that to any of the three wires labeled spare.  Then connect the other end of that spare wire which comes out by taillights to the 7-blade plug for the “brake” connector.  Doing so will activate brakes only when pedal is pushed and not when jake brake is engaged.  They said that the wiring has a couple of diodes between the brake switch and where the wiring ties into the jake brake.

Anybody have photo of the firewAll and/or the brake switch location on the firewall?  They tell me I’ll have to slide the generator out to access. Not sure I can even fit under the coach and don’t want to lift it unless absolutely necessary.
Rick V
2004 Beaver Marquis, Garnet (3 slides)
43'
C12