This is for a DD6V92TA with an Allison 740 Automatic transmission.
Wiring Jake brakes so as to have brake lights on when Jake's are in engaged.
This is for a 2 stage system: Switch on dash: OFF- LOW-HIGH
I used the following parts from DelCity: WWW.DelCity.net
2—Relays with/Diodes part #73986 Price $5.72 ea
2—Premade relay wiring harnesses Part #73570 cost $1.50 ea
You could use spade connectors connected directly to the relay and eliminate the wiring harness.
Terminal #85 or White wire is ---Ground
Terminal #30 or Black wire is----Positive or Hot I used the wire from the Buffer switch that is going to the switch on the dash where as it will only be hot when the ignition switch is in the on position.
Terminal #86 or Red wire is------Command I connected one from each relay to one of the wires that go to the Jake's under valve covers.
Terminal #87a or Green wire-----Goes to Brake lights
Terminal #87 or Blue wire--------Extra
The reason I used 2 Relays so as not to activate the High or both sides when I only need one side of the Jake's activated. “LOW”.
They work only when the Jake's are engaged. When the RPM’s drop below 1200 the Jake's kick out and the brake lights go off.