I am a total diesel dunce so bare with me...

From looking at diagrams of my fuel system I think the fuel temp sensor on my truck just died/melted/smoked and now I am stcu wondering what the heck happened and how do I fix it?

The electrical connection is the one on top of the fuel preheater towards the front of the engine from the lift pump and priming button. It is the conncetion on the top of the deal -- no the one on the side....

Im guessing it could have just slowly corroded over time as I had a small fuel leak on the rubber intake line right above it for a while... But why whould it smoke and melt??

I removed the offending piece and it came out with 2 T15 torks -- looks like it might have had a o-ring on it. Am I making any sense?

AND where do I get a new one? Part #, Cummins only part(I hope not)??

 

Common for them to melt down. Personally I think the wiring is too small.
Below are all the parts needed to completely rebuild the heater.
From Cummins:
heater element upper quad ring 3834185-s
heater strainer kit 3845400-s
heater element 3907766-s
cable harness 3843722-s

 

Thanks -- I had actually found the part number for the harness in another one of your posts via the amazing 'search' feature in the last few minutes...

So - what are the odds of just buying a new harness and tossing it in and having no more problems?

ALSO -- can I drive around with the harness unhooked as shown in the 2nd pic below? It may be a day or 3 'til I can get the part. OR get the harness hook it to the heater but not hook it to the truck so it doesn't work -- but seals up the heater??


Pics for those that like to look at stuff:

 

you need to replace eveything once you have a melt down.Remove the heater. It is very simply to delete by taking out the stem in the strainer. You'll see once it comes apart.

Once you get all the parts install as a package. Be very carefull with those square cut rings. I rolled one installing a new heater and it drove me crazy looking for that air leak in the fuel system.

 

Many of us have removed the pre-heater and left it out there are links to the how to do this, do a search. Mine has been out for about three years w/no problems. I live in thr north and it has been fine during the winter. Some per-heaters will leak air at the electrical connection and will be hard to find.

Floyd

 

Truck will run fine without it. I fried mine at the start of last winter - I didn't have any troubles. I don't live any place really cold though, so I can't comment on that.

 

So - I tried driving around with the temp sensor/thermostat melted down --- yeah that didn't work - it sucked enough air that the truck would barely start - then cough and stumble.

SO - not wanting to fully remove the unit I started the process to find a new wiring plug to make things seal up again... Again yeah right..

1) Called the Dodge dealer and got the run around - I even gave them the part # and the couldn't help me. Coached them through the parts schematic and they found no #. They said to call some diesel shop.

2) Called Diesel shop - they said why are you calling us? We don't do that kind of stuff. Call the dealer...

3) Called Cummins NW - they had one on the shelf -- but they are 1 hour away and do not deliver anywhere, period.

4) Called Hillsboro Diesel a local diesel shop -- they didn't have one and didn't actually have the part # in there system - but they trusted my # and 'ordered' it from Cummins NW -- they picked it up on there daily tripto Cummins NW and I had the part in my hand by lunch time -- but no o-ring! The whole freakin' part hinges on the o-ring. So we spent 10 minutes in the back at Hillsboro Diesel pouring through o-rings to find one that would work and finally found something in the CAT section... KUDOS to Hillsboro Diesel

Got the part home - installed in 2 minutes - Truck fired up -- coughed out the air in the lines and now runs like a champ.

 

Genos has everything you need. At the best price around as well. Give them a try they are on the net. I think they are genosgarage.com. I've replaced mine a couple of times but I use the truck up north in Canada for ski season and blend some wmo; so I use/plug-in the fuel heater relay when it's cold. No problems to date with 1/2 million mile+ between the two I have. cd

 

Your situation is kind of screwed now because you burned the fuel heater which is part of the fuel suction path. It will suck air and lose prime causing your current problems. The only way to find/show it is to pressurize the fuel system. I used an old fuel tank cap and threaded a fitting into it. I use it to pressurize the fuel tank and syste to about 3-5 psi and if you have a leak it will start dripping pretty quick. Also use the system to re-prime the fuel system when I change the fuel filters; after using it one time I thought it was worth the trouble, makes the filter change VERY easy.
Bottom line---you need to change the fuel heater or get rid of it....period....

hope this helps, cd