Redbull876

On 12/4/2017 at 11:22 AM, fjh said:

If you dig around in the console you will likely find to more vacant plugs   an on  switch on off and hi low  switch should be there ! once you got these rounded up and installed you need to go to a dealer and have the engine brake enabled in the computer end of things There are also two governer types in the program have this set to min / max it changes the way the engine brake feels when it  operates!

So the computer has to be program by mack for jake brakes to operate?

Call you're local mack dealer I know they can increase it 50hp with computer program. 

15 minutes ago, fjh said:

The wiring is likely there however you need to find it all !! there should be to wires and a plug near the clutch pedal for a clutch switch  likely wires in the center consoe marked engine brake and an empty relay slot or 2 in the fuse box and an empty fuse slot for engine brake!

If not its not that big of deal to run wire to run new wire!

There is a clutch pedal switch but it might be for the cruise control or might be for both idk. None of the wires in console is marked. It's an electrical fuel injection engine

I have 1999 rb688s e7 350hp EFI,  any how I bought jake brakes for it and installed it now my problem is wiring it in to truck. This truck never came with jake brakes but I found what I think is jake brake connectors under the hood and they plug on the jake brakes plug connector. My big question, is This truck wired for jake brakes even though it never had jake brakes? I tried finding connectors for jake brakes switches under dashboard but none of my wires or connectors is labeled. Is there a way of testing connectors?  I don't know because I believe it goes through the engine computer. (New to this jake brakes thing)

Anyone has any ideas it would be much appreciated.  Thanks in advance.