Gillig bus converted- Looking for retarder info

[Frankhaddad]

Detroit series 50 engine, Allison transmission. This unit has been modified into a motor home. Retarder does not work, wired to schematics that I could find with a module and joystick type controller as well as on/off switch. Have not been able to get it to activate during road tests. Have two codes Engine speed sensor, (22-14) and oil level (14-12). Not sure if these will have an effect on it activating or not. Also the cooling fan is supposed to be PWM variable speed but runs wide open. I have run the wire from engine ECU to fan solenoid, customer mentioned he had a Sauer-Danfoss unit but I can't find it in any drawings. The running gear (engine, tranny, etc) are all from a gillig bus mid 80's. Any info would be a great help!

 

[Truck Shop]

Engine speed sensor has to be hooked up and operable. Does the engine have a A/C unit? The Ac is also wired into the engine fan, A/C pressure switch, engine fan switch?

 

[Frankhaddad]

Engine speed sensor has to be hooked up and operable. Does the engine have a A/C unit? The Ac is also wired into the engine fan, A/C pressure switch, engine fan switch?

I can see the speed sensor on the schematics but not sure where to find it physically. And no, it was not equipped with A/C.

 

[Frankhaddad]

I can see the speed sensor on the schematics but not sure where to find it physically. And no, it was not equipped with A/C.

I also noticed on one schematic for the engine speed sensor that this is an optional harness? Would it be the flywheel sensor? I will trace that circuit out on my next visit. Any thoughts are great. Thank you.

 

[Truck Shop]

Correct.