Community Forums

36Fan · 01-17-2022, 12:21 PM

Hello,

I have a 2006 Dynasty with a ISL400 and Holset VGT turbo. The drivers side panel has two exhaust brake switches (identical), both are a on/off style position switch. Only one switch seems to activate braking. Both switches are wired with factory wires and connectors. Any idea of what the other switch is for? I have searched the net and can't find any info on double switches.

zmotorsports · 01-17-2022, 12:31 PM

Technically, your 2006 Dynasty with the ISL should have an engine compression brake and not an exhaust brake. On my 2003 model Dynasty, I only have one switch on the dash and it is to select between hi and low. Hi being all six cylinders and low being 3 cylinders. My Jake Brake switch to activate is on the floor by my left foot. I wonder if one of those is to turn on/off and the other is hi/low.

2-Nickels · 01-17-2022, 12:34 PM

Quote:

Originally Posted by 36Fan

Hello,

I have a 2006 Dynasty with a ISL400 and Holset VGT turbo. The drivers side panel has two exhaust brake switches (identical), both are a on/off style position switch. Only one switch seems to activate braking. Both switches are wired with factory wires and connectors. Any idea of what the other switch is for? I have searched the net and can't find any info on double switches.

One of those switches is on/off for a your Jake brake and the other is high/low for the Jake when on.

36Fan · 01-17-2022, 12:47 PM

The switch on the right is the one that works. Im assuming it is the on/off switch and the other is the 3/6 cyl switch. Being that the left switch isn't doing anything while activated, it must be in the high or 6 cyl setting because it is working and works well.

I have read numerous posts on exhaust brakes in relation to VGT Turbos etc but the holset part number and visual didn't seem correct for my set up. My owners manual lists an engine brake and no exhaust brake, but the switches are labeled "exhaust" .

Would like to hear from any members that have the switch set up like mine.

wolfe10 · 01-17-2022, 12:50 PM

Call Cummins with your engine serial number to verify what type of engine brake you have:

Engine compression brake/Jake brake
Exhaust brake
VGT brake

Are both switches just two position (on/off) or is one three position?

36Fan · 01-17-2022, 01:02 PM

Both switches are on/off 2 position.

Right switch has 10 terminals with wires connected to each. This switch will activate the brake.

Left switch has 4 terminals with wires connected to each. This switch doesn't do anything in either position.

36Fan · 01-17-2022, 01:41 PM

I called Cummins and found that the engine has a Jacobs 490 brake. Im guessing the switch that works is the on/off switch and the lo/hi switch is the 4 terminal switch that is either stuck in lo or hi. Im assuming it is in the hi position due to its performance.

Thanks everyone for the help.

windsorbill · 01-17-2022, 07:15 PM

My coach is probably very similar to your 06 dynasty regarding the engine brake. It's a Jake. One switch turns it on/off. The other switch turns it HI or LOW.

When I turn on the Jake, it will turn the cruise control OFF.

DiplomatDon · 01-17-2022, 08:26 PM

Quote:

Originally Posted by 36Fan

I called Cummins and found that the engine has a Jacobs 490 brake. Im guessing the switch that works is the on/off switch and the lo/hi switch is the 4 terminal switch that is either stuck in lo or hi. Im assuming it is in the hi position due to its performance.

Thanks everyone for the help.

If I remember right when the switch is to the rear it is on 3 cylinders and forward on 6. You are probably not feeling the difference however the next time you are on a good downhill [6 or 7 %] try both settings and you should feel the difference. The hi/low switch should actually say that. Former owner may have replaced it with the wrong one. On 3 cylinders is still better than exhaust brake was on my old ISC Diplomat and the Imperial is a lot heavier. Good luck Don.

RescueRamsey · 01-17-2022, 10:30 PM

If your on relatively flat ground and not towing the difference between low and high will be barely noticeable if at all. When you are towing or going down a steep grade the difference will be obvious.

36Fan · 01-18-2022, 09:21 AM

Unless Monaco used exhaust labeled switches for the Jake, the previous owner has swapped them out. The left switch would be the 3/6 switch, guessing from the 4 connectors on the rear of the switch. I have tried both settings on steep down grades without noticing any change. Having a commercial license for the last 33 years and driving multiple trucks with 3 stage jakes Im somewhat familiar with them. From the performance its proving now, Im guessing its on 6 cyl setting even though the switch position does nothing.

If I had a wiring schematic I could chase down which wire go where. Until I find a schematic, I will pull one wire at a time at the cylinder head to see if one or both are working.

Anyone have any pictures of the factory switches Monaco used?

vito.a · 01-18-2022, 12:16 PM

Your switches are Carling Technology Contura III except the Ex brake switches are a slightly newer Contura IV version. So yes it appears someone updated at least the covers.
You can purchase new custom switch covers at https://rockerswitchpros.com/

36Fan · 01-18-2022, 05:50 PM

Again thank you everyone for the help.

I removed the switch and it is a Carlington V4D1 (5) terminal switch. It is wired as follows.

#8 Positive
#7 Common Ground
#1 Hi/Lo SW 3
#2 Hi/Lo 2
#3 Hi/Lo 1

After looking at the switch schematic, Im thinking terminals 1 and 2 need to be swapped? Is the wire labeled Hi/Lo SW 3 the input and the other 2 are outputs?

Rc Pilot 55 · 02-01-2022, 02:04 PM

To add to the discussion on my 2 stage brake the 2nd stage only works under 35mph. If you are say doing 55mph and let off the throttle it will only brake on 3 cylinders until you drop below 35mph and then the 2nd stage(all 6 cylinders) kicks in. I don't know if you tried it at slower speeds but hopefully this will be of help.