Okay, with not much knowladge on what I am doing, I have been trying to figure out why my dually will sometimes stumble and die when it kicks off high idle. It will sometimes stumble and die when you put it in gear also. But, only when cold and usually only once. Once it gets it out of its system, it runs well.

I was looking at visible sensors this weekend and I found the sensor for the gauge in the dash. that is on the drivers side cylinder head just about in the middle. The sensor for the ECM appears to be by the thermostat right up front.

But then I have this sensor on the passenger side head that I can't figure out what the heck it is for. The sensor has been busted up bad. The connector housing is gone and there is just one prong that sticks out of the sensor. The connector going to it is just stuck on that prong. The sensor is on the passenger side cylinder head right about in the middle. Much like the gauge sensor. I had the truck running and unplugged it. No notice in idle changes hot or cold. No SES light. No gauge issues. Nothing. What the heck is that sensor for? It screws into the head so I am assuming that it goes into a water jacket, but I have no idea what it does. Any ideas?

It's for the aux electric cooling fan. Turn key on and ground that wire, the electric fan infront of the rad should turn on.

Funny thing is........I don't have an auxillary fan up front!

Not sure where they would of crammed one either. When I was having my transmission heat issue, I was going to install one up front and even with the slimmest fan I could find, I still could not get it to fit. And when I did get something up there, it actually made my heat problem worse! I had it setup as a pusher so it was pushing the air through the radiator. The fan could hold a piece of paper against the grill when on. But that just seemed to make the transmission and the engine hotter? So I scrapped the whole idea and eventually found my problem to be the computer and now I haven't had to worry about heat.

There are some electrical connectors tucked in the front bumper. I wonder if that's not the wiring for an auxillary fan then.

Perhaps when Frankenstein's doctor was putting Christine together, he forgot to install the auxillary fan?

Funny thing is........I don't have an auxillary fan up front!

How come this does not supprise me??:rolleyes:

A special fan does fit up there. Maybe someone could take a picture of theirs and post it.:)

I suspect the ECT sensor, here in post #8 http://www.dieselplace.com/forum/showthread.php?t=232498

Nope. Not ECT. That sensor is on the front of my engine. Right below the thermostat housing and it screws right into the block. It has 2 wires coming off from it.

Then I have my gauge sensor in the drivers side cylinder head that has one wire coming off from that. I know these two sensors because I have unplugged both with the truck running.

The pass cylinder head one threw me though. But it makes sense that this is what it would be for.

And now my head is spinning with the idea of trying, once again, to get my fan crammed in there somehow. Perhaps now that I have my transmission heat issue taken care of, it might be worth while.

Might be something I will look into when I tear the front end apart here this spring.