Jake Brake

[Paul Dobbin]

Our Land Yacht diesel pusher has the "Extarder" by Jacobsen, also
known as the "Jake Brake".
In our unit it quit working and my investigation finds power after the switch but not at the activator lever at the exhaust.
Question: Is there a circut breaker or relay somewhere between the dash
and the engine? If so where?
Any help is appreciated.

[blacksheep]

There should be a switch on the accelerator pedal or linkage, most likely a micro-switch. Make sure there is power to the switch and then through the switch when the accelerator is in the idle position. If not the switch needs adjusted or replaced.

Godspeed,
Trent

[Paul Dobbin]

Trent,
Thanks for the reply. I found the switch at the rear end of the accelerator cable. But no power to it.
I ran a jumper and that switch works when it gets electric.
I checked the Jake brake and it works with a jumper.
Problem is that the switch on the dash is hot on the out side, but not at the rear micro swtich.
I traced it from the dsah switch and it splts with one wire going in to the Allison shifer module. From there the wire going to the rear is dead.
Because I just spent $2700 getting that replaced, I'll take it back to Allison. That's to much money to risk self repairs.
Thanks for the help.
Paul

[blacksheep]

Paul,

Didn't think to ask if it was tied into the Allison. Could be as simple as re-programing if it is computer controlled. Yeah, I would take it back to them too. If it worked before they got hold of it they really need to fix this issue at no cost.

Godspeed,
Trent

[Paul Dobbin]

Well gang, after spending a day checking and rechecing, ?I was able to hot wire the Jake Brake and everything worked. The Allison ECU was wrong and had no program for the brakes.
It's in the Allison shop now and I hope no charge.
Thanks to all who responded.