J brake and brake lights

[LindyT]

Fortunately, the Cummins guy was there and I was able to watch him disable the brake light feature of the engine brake. It took him about 2 minutes. For those interested, using their Insite tool, it was in the Engine Brake Management menu and then something to the effect of "Discrete brake light output" -- change from enabled to disabled. Voila!

As an aside - I have a supplemental braking system. When the coach is slowing enough for someone behind to care, the toad brakes and brake lights will continue to activate, as one would expect.

[palehorse89]

Amen! I need to get mine done!

[Monacoach]

I have a 2008 Holiday Rambler Vacationer XL 340 cummins...... I don't have a clue if my brake lights come on with the jake...... does anyone know?

[Monacoach]

I guess you guys arent behind me.

[Romeo]

Quote:

Originally Posted by Monacoach I guess you guys arent behind me.

Push the brakes again and I will watch this time....

[RobRV]

This subject is of interest to Me due to a totally different experience. While searching My various Fuse Panels I discovered a Blown 7.5 AMP Fuse that was Burned almost beyond recognition. I removed the bits and pieces from the Fuse Holder which is labeled Aux Brake! I installed a new Fuse and almost immediately I started getting a Chuffing noise from the Rig. This didn't sound normal so I removed the fuse.
I figured that I should try to find out what was happening so I e-mailed Spartan.
The Reply I got was to tell Me that the socked labeled AUX BRAKE is for a Diode not a Fuse . This Diode is what causes the Brake Lights to come on whenever the Engine Brake is turned on. If the Diode is removed..... Apparently that's all it takes to disable the Automatic Brake Lights from being activated by the Engine Brake!

[Obi-Wan Kenobi]

RobRV.
That sound like a great idea. Although I do agree that the brake lights should come on when the toad & RV is being slowed, I do not want my toad brakes being applied. I normally use my J brake for long descents and this would certainly overheat and destroy my toad brakes on extended downhill grades like we have in BC.
US Gear had a module that is installed which stops the toad brakes from being applied when the J brake is activated. They could not install it on my coach for some reason, so finding this diode would do the trick for me.

[RobRV]

I guess if the Brake light triggers the Auxiliary Braking system that might do the trick!

[lajuene]

I'm getting an Invisibrake installed tomorrow and I think my coach has brake light activation on exhaust brake use. My exhaust brake is only a single phase brake, not a 2 stage like some others. I wish I had the 2 stage because my 1 stage does not slow the rig down as much as I'd like. However, because it doesn't slow it down that much I think I will have the ECM adjusted to stop the lights from coming on. My speed does not slow so fast as to be needed and I really don't want the toad brakes on even if it's only for 15 seconds at a time (as the Roadmaster website says of the Invisibrake).

Thanks for all the info here and if anyone has a 2004ish Winnebago let me know where the fuse/relay is. I'll be looking it up on the wiring diagrams but those puppies are hard to read.

[Obi-Wan Kenobi]

With the help at the Spartan factory, I was able to find the fuse for the brake light. They would not remove it, but once it was located, I took care of the rest. I do not have any ideas as to where your fuse would be, but with a little research, you should be able to find it.
Good Luck

[Qwert66]

OBI-Wan; So where was the fuse/diode located to remove and disable the engine brake causing the brake lights to come on ?
A picture would be very nice if possible as I want to do the same in a mine.
Behind the steering wheel, front of firewall, controls in back bay by engine cutoff sw., etc ?

Thanks for your time

[PandK]

I got this from Spartan a while ago. May help.

[Mr_D]

On our Newmar DSDP/Spartan the only brake light that comes on then I'm slowing using the exhaust brake is the center light. When I actually apply the brakes then all lights come on. Since I'm using the air actuated BrakeMaster it works as it should. Also, the exhaust brake coming on does not cancel the cruise control like it did on our previous DSDP/FL chassis

[Roadking]

Obi_Wan and others: About a year ago I read a post awhile ago about the Diode, it may have been an earlier post by RobRV. In my Bussman panel (aka chassis fuse box) there was only one diode so I assumed that was the one but I wanted to test it to ensure it was the correct diode. I had my DW press the brake treadle and tested for voltage on each side of the diode. Indeed, I had voltage corresponding to the brake lights on one side of the diode. So I removed the diode and wired in a temp brake light that I could see in my backup camera and went for a test drive.

Great news... It works as advertised. ... no brake lights when the exhaust brake is engaged....

and on 5 or 6 percent downhills my exhaust brake just holds my speed, so I'm more than happy that my lights are not on constantly during 10 mile downhills, such as I-15 between Las Vegas and Baker, or the hills in Colorado.