Community Forums

steined · 10-03-2015, 09:59 PM

I've got a 2000 dynasty with isc350 and can't locate the relay for the exhaust brake. I've checked connections and tested the air solenoid successfully. I hear clicking from the area under the drivers armrest when stepping on the brake switch above 5 mph but nothing happens with the PAC brake.

I've been pulling my hair out reading the wiring diagrams and all it says is that there is an exhaust brake relay, not where it is or anything.

I think the clicking is coming from the Allison VIM. It is a box full of relays and a couple fuses. The trigger wire for the exhaust brake supposedly comes from this box.

Thanks in advance.

H. Miller · 10-04-2015, 05:47 AM

PACBRAKE has a SERIOUS web site with diagrams etc. Also an 800 number.
What more could you ask for?

jacwjames · 10-04-2015, 02:37 PM

I would contact Monaco and request a Chassis wiring diagram.
Contact Monaco Coach

Fill out the form for current owners and what you are looking for, I requested mine ~6 weeks ago.

From there you can identify how the Pac Brake gets its single and an indication of where the relay (s) may be located. You can also send an email to Monaco tech support and ask them.

steined · 10-04-2015, 10:04 PM

I've got the full Monaco wiring diagram book, but it doesn't indicate the location of the PAC relay. I'll give pacbrake a call and see what they say.

Thanks

DtBt · 10-05-2015, 05:50 AM

My quess the VIM has the relay. The air solenoid for the pacbrake should be located above transmission. I could easily access it from under the bed on my Windsor. I rigged up a momentary test switch to test operation and work in the lube. Many times the pacbrake shaft freezes due to infrequent lubrication. There is a special lube from pacbrake but I always used Super Lube spray.

Tomjhall · 10-05-2015, 07:41 PM

Might be a silly question but will the exhaust brake activate at 5 mph? I took DtBts advice and built a momentary switch to test it. I had a air leak caused by misalignment when it was upgraded to a PR XB unit. The switch enabled me to test the brake while idling in the driveway parked. Trying to troubleshoot rolling down the road would be tough. You should be able to trace the line back from the brake to the solenoid. Good luck.