Exhaust Brake

[Ray,IN]

My brake lights (same chassis) are on when the exhaust brake is activated. Brake light fuse-15A- is located in the main chassis fuse/breaker panel above the genset. I think I remember my exhaust brake working properly when I discovered that blown fuse.

[KIX]

Originally Posted by Darrel

Kix - I am very interested in your problem since my RV has it also. I have only diagnosed my actuator at the exhaust pipe which was good. I wonder if you could narrow it down to the wiring from Bussman to solenoid or ECM to Bussman. If you could see if the brake lites are activated by the exhaust brake switch you could eliminate the ECM to Bussman portion.

Keep working, I'me rooting for you - Darrel

At this point I think the problem is between the Bussman and the solenoid. Solenoid works when applying external power. Per Spartan's help Bussman is good. Will have to road test to see if brake lights activate as designed. Just got to find time. This retirement stuff is pretty time consuming.

[KIX]

Originally Posted by Ray,IN

My brake lights (same chassis) are on when the exhaust brake is activated. Brake light fuse-15A- is located in the main chassis fuse/breaker panel above the genset. I think I remember my exhaust brake working properly when I discovered that blown fuse.

I have no fuse panel above the gen. Brake lights fuse must be good as brake lights work when parked as we check them for toad lights before driving.

[dennis45]

Originally Posted by KIX

I have no fuse panel above the gen. Brake lights fuse must be good as brake lights work when parked as we check them for toad lights before driving.

This test cannot be done until you're in motion. With the E Brake turned on, when you take your foot off the throttle, the brake lights should come on without touching the brake and shut off again when you accelerate. Will need someone following to confirm this.


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[palehorse89]

I am going to say that maybe there is a relay in one of your fuse panels the is controlled by the ECM, and when signaled by the ECM, the relay sends power to the air solenoid, which in turns moves the cylinder.
Sound like a bad relay.........

[Ray,IN]

KIX, look high up on the "firewall" above the genset(immediately below dash), there should be a black panel front that removes by turning/unscrewing four "T" handles. I'd be surprised if Spartan or Winnebago made a big change between your MM chassis and mine, both are Ultimates, yours 02, mine 00. On the backside of the 12V chassis panel/door you should find a fuse/breaker diagram identifying each fuse, breaker and relay.

[KIX]

Originally Posted by dennis45

This test cannot be done until you're in motion. With the E Brake turned on, when you take your foot off the throttle, the brake lights should come on without touching the brake and shut off again when you accelerate. Will need someone following to confirm this.


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Dennis.......you're right. NOw to get some time when DW is available to follow.

[KIX]

Originally Posted by palehorse89

I am going to say that maybe there is a relay in one of your fuse panels the is controlled by the ECM, and when signaled by the ECM, the relay sends power to the air solenoid, which in turns moves the cylinder.
Sound like a bad relay.........

Thanks Palehorse.......take a look at post #16. The relay is in the Bussman box and it checks good.......all that with Spartan's help.

[KIX]

Originally Posted by Ray,IN

KIX, look high up on the "firewall" above the genset(immediately below dash), there should be a black panel front that removes by turning/unscrewing four "T" handles. I'd be surprised if Spartan or Winnebago made a big change between your MM chassis and mine, both are Ultimates, yours 02, mine 00. On the backside of the 12V chassis panel/door you should find a fuse/breaker diagram identifying each fuse, breaker and relay.

Ray.........my chassis 12v panel is in the compartment under driver seat.

I'll bet you wish yours was there too.

[Ray,IN]

Originally Posted by KIX

Ray.........my chassis 12v panel is in the compartment under driver seat.

I'll bet you wish yours was there too.

Humm; different design from W. I like mine where it is, eye level. Only drawback, I must have a flashlight to see clearly inside the box. The only MH component in the compartment under driver seat is aftermarket. When Camping World replaced the HWH leveling module, which is very hard to access, they mounted the replacement on the ceiling of that compartment.
I hope you find the problem soon, It's getting closer to time to hit the road every day.

[KIX]

Originally Posted by Ray,IN

...................The only MH component in the compartment under driver seat is aftermarket.....................
I hope you find the problem soon, It's getting closer to time to hit the road every day.

In my under-driver-seat compartment the chassis 12v panel is in the lower 1/2 on the back wall. The compartment is divided......the upper 1/2 houses the surround system, the BIRD system and "house" 12v CB's. The another 12v house panel inside too.
The Ultimates are really nice coaches aren't they?

I hope I get it fixed soon too. Hopefully we can do a road test this Friday. Maybe tomorrow I'll get back on the phone with Spartan and ask some more questions.

[Darrel]

KIX - This may or may not help you but on my bussman diagram the exhaust brake wire is numbered SPo38D (pink). It is located on pin D of the orange connector. Also the diagram indicates that a splice (SPL60) is somewhere in the circuit. (It is somewhat confusing because one stage and multistage brakes are all combined.) At the solenoid the pink 18Gauge wire should be the other end.

Regards - Darrel

[KIX]

Originally Posted by Darrel

KIX - This may or may not help you but on my bussman diagram the exhaust brake wire is numbered SPo38D (pink). It is located on pin D of the orange connector. Also the diagram indicates that a splice (SPL60) is somewhere in the circuit. (It is somewhat confusing because one stage and multistage brakes are all combined.) At the solenoid the pink 18Gauge wire should be the other end.

Regards - Darrel

Darrel......thanks for that info. Sound like I'll need some help to check continuity in that.

Someone suggested that if brake lights don't work when ex brake should be activated then that may be the problem. Per Spartan brake lights have no control over exhaust brake. In fact brake lights can be deactivated when ex brake is on. Those that tow a trailer in mountains would not want brake lights on due to trailer brakes overheating.
So, next chance to get back at it is Saturday........I hope.

[KIX]

Well, it's working. The problem now is that I don't know what I did to fix it. I'm guessing that there was a bad connection in one of the connectors. I took a couple apart and cleaned although I didn't see any obvious problems with any of them.