Community Forums

GrandPaPat · 03-26-2019, 08:17 AM

On my last trip I noticed the exhaust brake was operating even though I had the rocker switch turned off. I typically only use it on hilly terrain or urban traffic. I exercised the switch while underway, but no joy.

I start a short three-day road trip Thursday where I can troubleshoot some ideas. Today I will look at rocker switch for loose or broken wires. Is there a relay and solenoid to look for? What would I look for after that?

Thx

Old-Biscuit · 03-26-2019, 08:27 AM

Sounds like rocker switch is shorted....ON

Gary.Jones · 03-26-2019, 04:01 PM

I’m betting your switch is bad and always “on”. Try removing the switch and then remove one of the wires and take a little trip down the road and see if the Jake is still “on”. It shouldn’t be. If it is, then you may have a problem with the solenoids or relays that actually turn the Jake on or off at the engine.

Gary

Butte64 · 03-26-2019, 05:02 PM

Since it is a 3 position switch does it operate the same in all 3 positions? That could give a clue on whether it is a switch problem.

HR2004 · 03-26-2019, 05:13 PM

If it is a Carling Brand Switch It can be taken apart carefully and the contacts cleaned. Watch for flying springs.

Neverhome2 · 03-27-2019, 10:20 AM

Why not just leave it on? We never turn ours off and it works great!

brobox · 03-27-2019, 10:36 AM

Quote:

Originally Posted by Neverhome2

Why not just leave it on? We never turn ours off and it works great!

However, I would loose my favorite speed....coast

GrandPaPat · 03-27-2019, 09:22 PM

I disconnected the whole rocker switch this afternoon. Will drive 150 miles Thursday so will see what happens.

Big Mike at Spartan School says don’t run exhaust brake all the time.

If I replace switch I will move it forward to the slot where the mirror heater switch is located. That is a much easier place to see and reach quickly when needed.

And I don’t like the lack of ability to coast either.

Rollin101 · 03-28-2019, 05:02 AM

Quote:

Originally Posted by GrandPaPat

I disconnected the whole rocker switch this afternoon. Will drive 150 miles Thursday so will see what happens.

Big Mike at Spartan School says don’t run exhaust brake all the time.

If I replace switch I will move it forward to the slot where the mirror heater switch is located. That is a much easier place to see and reach quickly when needed.

And I don’t like the lack of ability to coast either.

Spartan or Cummins can program your ECM so your Mh will coast, even with the jake on, until you touch the brake. There has been a lot of discussions on here about jake off or on, but I also leave mine on all the time and have had my ECM reprogrammed so Mh will coast until I touch the brake. Then the jake will stay on until you touch the throttle or turn the switch off.

Gasman 2 · 03-28-2019, 05:14 AM

Pat you have a compression brake or some call it Jake brake. An exhaust brake is a different animal.
A compression brake when activated opens the exhaust valves after the compression stroke slowing the engine.
An exhaust brake is simply a butterfly valve in the exhaust pipe.
Sorry I can’t help you with the issue but what are you seeing on the dash? Is it showing the engine Brake is on?
Also does the Allison shift pad indicate 2nd gear when you take you foot off accelerator?
Hope you find the problem soon.

Richard

GrandPaPat · 03-28-2019, 06:14 AM

Thx, Gasman. I was aware there was a difference in engine brakes just couldn’t remember which was on Anthem. Did not know about ECM trick so that would be a good mod. The info display shows “auxiliary brake” when I take foot off accelerator and Allison keypad shows 2nd gear as the target gear. The rocker switch module did not have any burn marks on the contacts.

Gary.Jones · 03-28-2019, 07:28 AM

If the dash shows it is dropping (or trying to drop) into 2nd gear when you take your foot off the "gas" pedal, then you jake is definitely "on" all the time.

People do that, but they experience a much "jerkier" ride when they have the jake on all the time compared to when they have it on only when they need it (like going down a long hill). Individual choice, but I dont like the "ride" of the coach with it on when I dont need it. Different strokes.

Gary

GrandPaPat · 03-28-2019, 05:45 PM

The jake brake is still on with the rocker switch disconnected and it is stuck on high setting. It is way too jerky a ride that way!

Gary.Jones · 03-28-2019, 05:51 PM

Pat

It could still be electrical just further upstream.

However, I have no experience with the Jake not shifting on or off so please be sure and add to this thread when you get a handle on this situation.

And yes, having the jake on high all the time would be terrible.

And your warranty from Cummins is 5 years and Spartan is 3 years. I would get talking to Spartan and Cummins right away and see what they have to say. You want to get it registered into the system right away, IMO.

Gary