Engine/Transmission (1994 - 1998) Fuel Heater wires melted...what have people done to correct that?

[Dan_69GTX]

The connection for the fuel heater is now toast! So for now I just disconnected it. Everything else is fine - I checked the thermostat and the heater and the power to them.



It seems there was a bad contact at the plug for the power (located by the fuel heater).



In looking at the manual and checking the resistance of the fuel heater itself - what can be done to minimize the resistance of the electrical connection? If the resistance of the heater is 1 ohm and the resistance of the connection is 1 ohm, then you are having 150 watts oh heat buildup at the electrical connection and 150 in the heater. Soldering the connection would be best - but that doesn't help when you have to remove the fuel heater.



Any suggestions - or what have you done before?



Thanks!

Dan

 

[HEMI®Dart]

Good question, Dan

My heater connection has done the same thing. I may cut off the burnt end and replace it with female spades, and hook into the male end without altering the good side.



If anybody has a better idea please post.



I wonder if just the female connecter is available in pigtail type configuration?

 

[HEMI®Dart]

I unplugged my connection for the fuel pre-heater heater today for the summer and see that the connection is all burnt. The wire leading into the connector is showing major heat damage. I used new dielectric grease every time when I hooked it up in the fall for about 5 years now. I surfed the old posts and found that resistance in the plug itself will cause it to burn.



The fuel pre-heater itself looks fine. Only the connecter is toast.



I don't want to hard wire it because I like to disconnect the heater in the spring. I was doing something about 5 years ago on a 90° day, and found the the heater was still coming on. I replaced the relay on the firewall and sit still did it. I 'd swear the engine idles smoother w/ the heater unplugged in cool weather.



I was going to use posilocks but it looks like I will need to add wire. That means 4 of them. Is there a connection like the OEM that could be used?

 

[Joe G.]

If the wireing is burned the fuel heater is probably burned out inside and not working. The inside damage is normally not visible. This situation normally causes an air leak inside the electrical connection. The use of dielectric grease probably blocks the air leak.

 

[CumminsPower98]

I agree with Joe. The heater is probably fried. My heater, thermostat and the plug were fried on mine. The original heater design is not good as the parts inside are just spring loaded friction contacts at the plug pins. The updated version is crimped inside. The main power plug was a bit melted on mine but I just made sure the spade on the melted side was bent down tight and it seems to work ok.

Cummins/Fleetgaurd part numbers:
Fuel heater 3907766-S
Harness 3843722-S

HEMI®Dart, if you don't want the heater running can't you just remove the fuse? My '98 has the fuse and relay in the PDC. I know '97 and older have the relay on the firewall but I don't know where the fuse is for those.

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[DJWyckoff]

I removed my bowl, screen, heater and all reached up inside with an allen wrench took the adapter cheaked the seal and installed the bowl screen with out the heater. mine was sucking air in. my truck lives in WV or NY and has no trouble I plug it in put it on a timer for 80min before I have to leave for work it does fine condition the fuel to prevent jelling. I would not waste my time with fixing it. just my opinion.

 

[HEMI®Dart]

Great pictures and part numbers CumminsPower98. Thanks too Joe. I think I will replace the whole assembly this summmer. I have taken it apart before. How does the temperature? sensor on top come off? I am not sure if the pre-heater has a fuse. I just unplug the grey connector.



Hey, did the connector that plugs in the heater itself ( the plug in at the actual heater) look burned on your old one? I just looked at mine and it still looks new.

 

[CumminsPower98]

I'm pretty sure the one side of the heater plug on mine was a little melted. The sensor has two little screws that hold it on the top there. They are a really small torx head but I can't remember the size.

Great pictures and part numbers CumminsPower98. Thanks too Joe. I think I will replace the whole assembly this summmer. I have taken it apart before. How does the temperature? sensor on top come off? I am not sure if the pre-heater has a fuse. I just unplug the grey connector.



Hey, did the connector that plugs in the heater itself ( the plug in at the actual heater) look burned on your old one? I just looked at mine and it still looks new.

 

[Joe G.]

My heater looked just fine until I took it apart. The sensor was fried. The plug and socket looked ok. When I put some air pressure to it and put it in a bucket of water I had bubbles coming out of the electrical connnect.

 

[DODGEDADDIE]

HELLO. .

Isn't that part number for the SCREEN An gasket? And not for the NEW UPDATED HEATER??



JUST ASKING



THANKS. .

Mike In Maine

 

[HEMI®Dart]

Mike,



3845400-S is the p/n for the pre-filter screen & gasket kit.

 

[DODGEDADDIE]

THANKS for the p/n info. .



MY MISUNDERSTANDING



Mike

 

[MHalloran]

Mike,



3845400-S is the p/n for the pre-filter screen & gasket kit.

Is this a DC part # or a Cummins part # ? Thanks.

 

[CumminsPower98]

Cummins part number.

 

[Joe G.]

Here are the part numbers I have:



Fuel heater/pre filter

... ... . Fuel supply line fitting grommet... ... Cummins... ... ... 3923194

... ... . Fuel Strainer... ... ... ... ... ... ... ... ... ... ... . Mopar... ... ..... 04762962

... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... . Cummins... ... . 3847102

... ... . screen kit... ... ... ... ... ... ... ... ... ... ..... FleetGuard..... 3845400-S

... ... . pre-filter O-ring... ... ... ... ... ... ... ... ... FleetGuard..... 3834185-S

... ... . heater element

... ... ... ... ... (includes 3834185-S)... ... ... . FleetGuard..... 3907766-S

... ... . cable harness... ... ... ... ... ... ... ... ..... FleetGuard..... 3843722-S





Here is what the fuel heater/pre-filter looks like without the heater unit:



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[The patriot]

When I bought my 98 new it wasnt plugged in.

I got a recall for the dealer to hook it up.

It fried last year with about 100K miles on it.

I just did what Joe did. Bypass it.

Eric

 

[HEMI®Dart]

My heater element does not look as burnt as CumminsPower98 was. Some heat damage though. Bottom pic is the OEM heater (top) and the new revised heater from Cummins. (bottom)

 

[Katmandu]

My heater looked just fine until I took it apart. The sensor was fried. The plug and socket looked ok. When I put some air pressure to it and put it in a bucket of water I had bubbles coming out of the electrical connnect.

I squirted a small tube of Super Glue into the electrical connector to seal the leak.

Seemed to work! My truck isn't losing prime anymore. Starts right up the 1st time and seems to be running ALOT smoother!

.

 

[Joe G.]

Why not just take it out? And leave it out? It's not working and may cause problems again.

 

[Katmandu]

Why not just take it out? And leave it out? It's not working and may cause problems again.

I haven't had the time to do it yet.


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