no power on 1 of 2 busses behind circuit breaker panel,where does power originate from to power up the circuit breakers?

[slingblade]

on my 85 superliner the guages didnt work and i traced the problem back to the circuit breaker panel using the RD wiring diagram,specificly the power busses behind the panel that supply power to the different circuits,one of them is dead,the wiring diagram doesnt show where they get power from,does anyone know?i could run a patch from the good buss to power up the dead one but id rather find the problem and fix it there,,any help would greatly be appreciated

[slingblade]

found the problem,assesory relay under the dash section where you normally mount cb radio theres a heavy duty relay that looks like the old ford start relay,it powers up the upper buss that supplies power to the guages,lights and buzzers,going to replace it with a new ford starter relay

[gearhead204]

slingblade don't use the ford solenoid, use a continues duty solenoid the ford is interminiet use

[wheeler73]

Best to use a good marine continuous duty solenoid. They last the longest.

[slingblade]

yup,the ford relay lasted a day,49 bucks at the mack dealer and i got the correct one,now to undo all the wiring work arounds the last owner did to it,got most of it back to original except for the 3 stage jake brake wiring,this should be a challenge,,