KSB Relay Temperature Sensor

[rwinslow]

Does anyone have a part number for the KSB Relay Temp. Sensor? Where in the head does the sensor mount? If the everything is working correctly, (i. e. engine at operating temp. ,) what should the voltage at the KSB relay read? Thanks!!

 

[formula]

Do you mean the KSB solenoid? There is very little wiring in this circuit. There is a lead that runs from the shutoff solenoid to the temp switch and then to the KSB solenoid, that's it. The sensor is just a "thermal switch" and that's what the Dodge description of the part is. I don't know the number offhand. There are two temp sensors on the intake manifold. The smaller that is closer to the intake horn is the temp sensor for the computer. It has a smaller plug with 2 terminals and has nothing to do with the KSB function. Also, this sensor has a longer, more narrow probe inside the manifold. The KSB temp switch is the one that's closest to the firewall. Its plug is a bit larger and has 3 terminals. The probe on the thermal switch looks quite like the brass (copper?) wax motor on a coolant thermostat. This switch is either on or off supplying +12v to the KSB solenoid. You can check it when the engine is cold to see if the KSB has +12v. The thermal switch on my truck melted down in a cloud of nice plastic smoke a while ago. The part number is stamped on the body of the sensor. Be careful when you take it out so you don't rub off the numbers. You can put a 1/2" pipe plug in its place until you get a new one. If the harness is cooked, you'll have to get it from cummins, part # 3923303 ~$16. The thermal switch costs about $50 from the dealer. It may be available from cummins also.



Cheers,

Sean