Redbull876 Posted December 4, 2017 Share Posted December 4, 2017 (edited) 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. Edited December 4, 2017 by Redbull876 Quote Link to comment https://www.bigmacktrucks.com/topic/51851-jake-brake-wiring-on-1999-rb688s-e7-350-electrical/ Share on other sites More sharing options...
fjh Posted December 4, 2017 Share Posted December 4, 2017 (edited) 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! If it is a manual lever engine Edited December 4, 2017 by fjh Quote Link to comment https://www.bigmacktrucks.com/topic/51851-jake-brake-wiring-on-1999-rb688s-e7-350-electrical/#findComment-386485 Share on other sites More sharing options...
Redbull876 Posted December 4, 2017 Author Share Posted December 4, 2017 (edited) 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 Edited December 4, 2017 by Redbull876 Quote Link to comment https://www.bigmacktrucks.com/topic/51851-jake-brake-wiring-on-1999-rb688s-e7-350-electrical/#findComment-386487 Share on other sites More sharing options...
fjh Posted December 4, 2017 Share Posted December 4, 2017 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! Quote Link to comment https://www.bigmacktrucks.com/topic/51851-jake-brake-wiring-on-1999-rb688s-e7-350-electrical/#findComment-386520 Share on other sites More sharing options...
Redbull876 Posted December 7, 2017 Author Share Posted December 7, 2017 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? Quote Link to comment https://www.bigmacktrucks.com/topic/51851-jake-brake-wiring-on-1999-rb688s-e7-350-electrical/#findComment-386763 Share on other sites More sharing options...
fjh Posted December 14, 2017 Share Posted December 14, 2017 Settings need to be enabled in the software not really reprogramed but changed! Quote Link to comment https://www.bigmacktrucks.com/topic/51851-jake-brake-wiring-on-1999-rb688s-e7-350-electrical/#findComment-387431 Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.