Problem with Jake Brake

[Pete Masterson]

The operation of the Jake brake is not a simple electro-mechanical device -- it uses the engine computer module to actually engage or disengage the brake. So, if you're sure that the electrical system (including the cannon plugs) are all up to snuff, then it's time to get a DD technician to plug in and check the ECM with a reader device.

Pete Masterson

'95 Blue Bird Wanderlodge WBDA 42

El Sobrante CA

"aeonix1@mac.com"

On Jul 14, 2009, at 6:45 AM, g_man1146 wrote:

I have a series 60 Detroit with a three position Jake brake. Originally it was wired to either be "Off" or come "On" with throttle lift. Blue Bird added a wire to the brake light relay and changed the switch so it has a center "Off". One way it works as before with throttle lift and in the other position the Jake comes "On" when the brakes are activated.

Occasionally it stops working altogether and when this happens I pull the relays in the compartment under the drivers window, spray the sockets with cleaner and all is well for another year or so. (Bennie showed me this "fix")

The last time this happened only the "throttle lift" mode started working again. The relays, wiring and switch check OK. The green LED next to the switch lights when the service brakes are applied so I know the trigger voltage is there. Any ideas on what to try. The Jake works normally in the "Throttle Lift" position just not in the "On with Service Brake" position.

Thanks for your help!

Rich D. '99LXi43' CT