Ok, I figured out the sensor issue so see update below...

 

Not sure any pics would help

 

That's it in the lower right, behind the black peiece of stamped steel. Has one wire running through it from the intake air temp sensor.

 

the only thing i have seen there is the coolant temp sensor only one wire on it best i can do with out the cover off hope that helps.

 

It's a resistor to drop the voltage to the KSB. I think it's like 7 ohms or so, I'd have to look in a book.

 

I took it off today, you are correct. Resistor to the KSB...BUT somebody's been in my wires! I'm chasing a constantly on KSB. I pulled the air temp sensor today, plugged it off and gutted the kill solenoid. Will this sensor being MIA affect my grid heater? I still have power all the time to the KSB. I checked the charge air temp sensor (the one on the left in the pick) and it's clean. Reinstalled, still hot at the KSB. I'm thinking someone prior to me owning this truck hotwired it (it's page us marked in the service manual that came with the truck) but I don't see where they pulled power from. The rest of the harness is intact.

 

Are you sure you unplugged the right sensor? There's a switch for the KSB and a sensor for the PCM.

 

The KSB switch is powered off the shutdown solenoid. Is the switch open at temps above 60 degrees?

 

The shutdown solenoid is MIA at this point. Gutted, no wires running to it anymore. If I remove plug from the CAT sensor (left in photo) I still have hot. It was my understanding that the KSB pulled power from this sensor when charge air is "cold". What sensor tells the grid heaters to come on?

 

Pcm?

 

PCM

 

That's the air temp sensor, not the KSB switch. The KSB switch is the one closer to the firewall. It's a thermal switch that closes below 90 degrees. Power is supplied off the shutdown solenoid. You say that's disconnected, but what did you do with the wires? Did you splice them together?

 

The two wires that originally ran to the shutdown solenoid were spliced awhile back so there was only one wire running to the shutdown. Yesterday, I removed the line entirely as my **** is gutted. The only wires running to it came from the sensor in question which is also gone at this point. Thus, the sensor on the left in the pic is in place, clean, and apparently functional. The issue is I still have a constantly on KSB and for the life of me, I cannot figure out where it's getting power from. I guess I'll trace the wire running to it back through the harness...? It should be getting power from the remaining sensor, no? Also, which sensor (if any) tells the grid heater when to come on at startup (PCM?)? For that matter, what tells the grid heater to turn off, the PCM?

 

When I discovered the tangled mess of shorted out wires in my loom, I did several things regarding my fuel shut off solenoid and KSB :

1) Disconnected the wires from both.

2) Wired one line from the battery to a switch on my dash, and a line from that to the fuel shut off solenoid.

3) Sent another wire from the solenoid back to a second switch on the dash, and a wire from that to the KSB.

4) Forgot all about the KSB's temp sensor and it's wires, and lived happily ever after.

Now when I want power to the fuel shut off solenoid, I flip a switch. When it's cold and I want the KSB on, I flip a switch.

 

sounds like what I did so much easier with switches