Jake Brake Modification

[Richard and Rhonda]

I didn't like running with my jakes on all the time because the throttle was so senstive I could not consistently ease out to coast without the jakes coming on. That kind of irritated me hearing the jakes come on while coasting down a small hill.

So, I modified my jake brake circuit to have it work a little differently. Honestly, I bought a Brakeswitch, but ended up not wiring it as they recommended.

Here is how I have it working, and I'll attach a schematic if you want to do something similar. I have changed the system so that the Jakes come on when I depress the brake pedal. The jakes release when I release the pedal. They do not actuate when I roll out of the throttle. They do not "latch" when I press the brake pedal. I did this on purpose so that the jakes come on anytime I apply the brakes.

I can still turn off the jakes, by simply turining off the jake switch like you would normally do.

Here is the sweet part, by adding one additional toggle switch, I can revert back to the original setup. That is the jakes actuate and stay on when the accelerator is released. They unlatch when you press the accelerator.

I added this feature, because there are times when that setup would be useful. Such as descending a long grade. If I used my brake activated mode, I would have to ride the brakes all the way down. I wouldn't want to do that.

If you want to do this you'll need a standard 12V relay, one diode, about 20 ft of wire, and a few crimp on terminals.

Look at the schematic. Here iu what is going on. We are taking the hot wire from the Jake Brake on/off switch and interruping that wire. Just remove the panel with the on off switch, my wiring was purple with yellow stripe. Use the voltmeter to determine which wire is downstream of the switch. Mine was on the front of the switch. By putting the new brakeswitch relay in this circuit, we are using the brakeswitch relay to turn the jakes off and on. I ran two wires from the kickwell where I mounted the relay all the way back to the jake on/off toggle. I used one male and one female crimp on to simply insert the new wiring into the existing circuit. Easy to undo if I didn't like the result.

The trigger wire for the brakeswitch relay comes from the brakelight circuit. Look at the wiring schematic for the passenger kick well and find the correct wire on the terminal board. You'll have to ground the other side of the relay.

If you want to install the bypass switch that makes the jake function, simply put a toggle switch to jumper around the brakeswitch relay.

I did this a couple of weeks ago, but I didn't want to post until I had a chance to drive the coach. We took a little 250 mile trip this weekend.

How did it work? SWEET !!!!!!! I now have the best of both worlds.

You don't have to spend the 80 bucks for a Brakeswitch that I did. A standard 12V relay with a diode to prevent a voltage spike back into the brake circuit would do the trick.

If this didn't make sense let me know.