Engine/Transmission (1994 - 1998) Fuel Heater Melted

[ETaylor]

I was increasing the idle on my '96 the other day and noticed some wires kinda dangling and looked at my fuel heater. The sensor on top of the fuel heater that senses the temp of the fuel had melted down flush with the fuel heater and had totally destroyed the connector. I went to dodge after a stop at Napa and they told me that I would have to buy the entire fuel heater assembly which includes the wire harness. So here's my question:



1. Does anyone know if I can get the wire harness and sensor without buying the complete assembly?



2. What would cause this to happen. I really don't want to put another one on just to have the same thing happen again.



Thanks for your input.



ETaylor

 

[Vaughn MacKenzie]

ETaylor yes you can buy them separately, they are Fleetguard parts which are FAR cheaper than you can get from Dodge (get them from Cummins):



Fuel Heater: 3907766-S (around $35 if I recall)

Wire Harness: 3843722-S

Prefilter service kit you should do while everything is apart: 3845400-s (about $8)



More info: http://dodgeram.org/tech/dsl/filter/pre-filt_clean.htm

Part numbers: http://dodgeram.org/tech/dsl/Facts/96specs.html



Vaughn

 

[Joe G.]

You can take the fuel heater out and leave it out. Not needed unless you live where it gets really cold. The screw that holds it in is really just an adapter. Remove it and the pre-filter will go right up in place of it.

 

[ETaylor]

I thought about that but here in Ky our weather can do anything. We have winters that can get down into the single digits but can also not hardly even break the freeze mark. I was goin to try to get a pic today of the melted sensor and post it but didn't get around to it. Can you replace just the sensor. I looked at the websites posted and didn't see the sensor on the parts list but could have just over looked it. thanks for the input



ETaylor

 

[Vaughn MacKenzie]

The sensor melted? I misread your original post. I have never heard of that happening before, the heater plug is what usually melts. I'm pretty sure it's included as part of the wiring harness listed above though. The wiring harness has a plug that connects to the main wiring harness underhood, and the other end has both the sensor and heater connectors. It's only about 10-12" long and a snap to replace.



It could be the sensor and heater wiring are part of the same harness so maybe the PN I listed above is it. Here is a pic that might help http://dodgeram.org/tech/dsl/Facts/figures/12Ve_locations-l.gif



Vaughn

 

[Evan A. Beck]

Whenever we see those stupid heaters and/or wiring broken, we just eliminate them. It's a far better way to go, since the heater/strainer assembly is prone to air leaks anyway. When we do it, we just tell people to run a good fuel additive when it gets really cold. Gotta remember too, if it is cold enough to cloud the fuel, then its what is in the tank that is most important! The little fuel heater on the engine won't solve that problem...



Take it out and leave it out!

 

[Vaughn MacKenzie]

Even people from colder climates Evan? I always figured it helped warm fuel for better atomization & combustion, not to just help prevent gelling. Otherwise I'd pitch mine too!

 

[Joe G.]

The sensor melted? I misread your original post. I have never heard of that happening before, the heater plug is what usually melts.

Vaughn

Mine did exactly that. The sensor melted. From what I can tell the sensor failed. That caused the fuel heater relay to stay on which burned up the heater element contact inside my fuel heater. That got the connector pin that is connected to the contract that melted very hot. The result was an air leak around the pin. It could not be seen, but submerged in water with a little bit of air pressure made a lot of bubble from the base of the pin. I agree with Evan. Throw the thing in the garbage where it belongs and don't replace it. I wonder how many Dodges are running around in cold climates with a burned out fuel heater and don't know it.



ETaylor,



I was stationed in KY when I was in the Army in the early '60s and lived in Paris. It was -34 one morning.

 

[R.ebel]

Heater

Even people from colder climates Evan? I always figured it helped warm fuel for better atomization & combustion, not to just help prevent gelling. Otherwise I'd pitch mine too!

The haeter on my truck melted the plug some time ago, also caused an air leak. Replaced the heater but never hooked it back up. For those that are worried about cold temps with the heater unplugged, if you are running a good fuel treatment the heater is not needed. I've been as low as -22F this last winter with no problems at all

 

[ETaylor]

ETaylor,



I was stationed in KY when I was in the Army in the early '60s and lived in Paris. It was -34 one morning.

I live in Cynthiana just about 10 minutes north of Paris.



Thanks everyone for your replies but you have led me to come up with 2 more questions :-laf



1. How do you know if you have an air leak?



2. If i do discard the fuel heater how do you hook everything up? Or is it self explanatory?



ETaylor

 

[Joe G.]

The screw that holds the fuel heater in is really an adapter. It has the same threads on both ends. Top is male, bottom is female. So all you need to do is remove the fuel heater, one gasket, and the screw. The pre-filter will go right where the heater was. No problem.



You can't see an air leak so you have to test for it. If removing the fuel heater doesn't fix it (you may have more than one air leak) then look here:



http://dieselram.com/ubb/ultimatebb.php?ubb=get_topic;f=45;t=000007

 

[Evan A. Beck]

Hey Vaughn, the Dodge truck is one of the only B5. 9 12V applications using the prestrainer/heater. Every heavy truck/motorhome I have worked on has never had a fuel heater installed. In fact, most of them don't even have grid heaters! No fuel problems or hard starting due to cold either...

 

[Vaughn MacKenzie]

Thanks for the info Evan. Mine might accidentally fall off at some point

 

[DODGEDADDIE]

So does any one know why all these HEATER SENSORS are burning / melting out??

I found mine like this,,cause I had that pain in the BUTT fuel leak down there !!!!

Also I found the SOFT spring also broke,, does any one know what that one really does,,NOt the stiff one .



THANKS



Mike In Maine

 

[DODGEDADDIE]

HOWDY,,

I JUST bought the fuel hearter parts mentioned above, From a CUMMINS dealergone up ALOT,,

#3907766-S,,,,,,,, Was $39. 23

#3843722-S,,,,,, Was $58. 33

 

[Katmandu]

So does any one know why all these HEATER SENSORS are burning / melting out??
I found mine like this,,cause I had that pain in the BUTT fuel leak down there !!!!

Good question!

Why are these heating elements failing so much ??

And more importantly I believe... . When they do go bad, why aren't they blowing the fuse in the circuit ????

 

[HEMI®Dart]

I am thinking about getting rid of my heater.



Question: What do we do with the temp sensor that is attached to the top of the assembly? It's not part of the heater right? Do we remove it or leave it?

 

[KYOUNG]

Unplug it!!

 

[HEMI®Dart]

KYOUNG,



Thanks. I thought it was attached w/ torx screws.

 

[DODGEDADDIE]

It is ATTACHED to the body . . with the TORX screws,You can unscrew them if you wish (or can get to)

That attachment is your so called element,It does not open up the top of the body where the fuel is.

Unplug if you wish!!!! BUT WHY DO YOU WANT TO?????????

CUMMINS Put them there for a reason... ... ...