SAFETY WARNING: unplug your fuel heater element

budmeister · **Posted:** Mon Dec 10, 2007 1:31 am

I read either here or somewhere that the fuel heater and the glow plugs shared the same relay and passed that on here but in looking through the electrical section of the service manual this weekend it shows specific fuses on the fuse panel for each. You might want to pull your owners manual and then refer to your fuse panel to see what's up with the conflicting Chrysler data.[/quote]

Just took a look under the hood of my CRD to confirm the infamous fuel heater plug. Yup, it's there. Anyhow, I found a description of the fuel heater on page 1594 of my manual that says:

"The element inside the heater assembly is made of
a Positive Temperature Coefficient (PTC) material,
and has power applied to it by the fuel heater relay
anytime the ignition key is in the “on” position. PTC
material has a high resistance to current flow when
its temperature is high, which means that it will not
generate heat when the temperature is above a certain
value. When the temperature is below 7°C (45°
F), the resistance of the PTC element is lowered, and
allows current to flow through the fuel heater element
warming the fuel. When the temperature is
above 29°C (85° F), the PTC element’s resistance
rises, and current flow through the heater element
stops (Fig. 27).
Voltage to operate the fuel heater is supplied from
the glow plug module, through the fuel heater relay,
when the ECM senses the ignition (key) switch."

I know this doesn't help in any way with the problem as reported, but at least gives some insight on the 'theory of operation'.

gmctd · **Posted:** Mon Dec 10, 2007 1:41 am

Good input, bud - I have read that and, in fact, reworded it for clarity in a post on the CP3 injection system on several forums - prollem is, if some areas of the heater are submersed while other areas are not, full current flow will attempt to bring the wetted areas up to temp, which can over-temp the un-wetted areas - I think that is what is occurring in some cases, as opposed to simple module defect.

But, as o-t-h stated, it's unprovable either way unless I can get up close and personal with the module(s) - don't look like that's gonna happen, anyways soon.

ATXKJ · **Posted:** Mon Dec 10, 2007 11:39 am

FYI - the pump in the CRD is large enough to overcome small vauum leaks - however that still leaves an air pocket around the heater element when it stops/starts.

A vacuum leak is very, very difficult to identify until it's large enough to drip out and by that time there's been a lot of air pumped though the engine.

Actually I'm not sure how auto techs would diagnose a vacuum leak, we do it at work all the time - but we're in the milli to micro Torr range and we have very specialized equipment to troubleshoot none of that exists for an automotive application.

ATXKJ · **Posted:** Mon Dec 10, 2007 2:54 pm

gmctd
The Fleetgaurd may be more problematic than the lift pump
using SirSam's links to 03 parts and the Mopar Parts America link I came up with these

No complete assembly list - only seperate parts
Fig 14-320
5015578AC..........Head..............21
68001914AA........Filter...............16
5093123AA..........heater.............97
5093128AA..........Water Sensor.134
5093124AA..........Thermostat......52
5093122AA..........housing.........130

so about 450 just for the big parts - I didn't check on all of the fitting and connectors that are also listed seperately
unless there's a Fleetgaurd or Dodge dealer who can sell an entire unit at a reasonable cost.

gmctd · **Posted:** Mon Dec 10, 2007 4:36 pm

Good (or maybe bad, from another perspective) input - but, have I overlooked a link for Dodge-specific parts manuals?

ATXKJ · **Posted:** Mon Dec 10, 2007 5:23 pm

Take Sir Sam's KJ parts manuals - back up a couple of folders in the URL and he's got Dodge/Jeep/Nissan/VW
beware the FSM is over 80Meg

KJ linkhttp://colorado4wheel.com/manuals/Jeep/KJ/

Dodge+ linkshttp://colorado4wheel.com/manuals/

gmctd · **Posted:** Mon Dec 10, 2007 9:25 pm

Ok - got it - thanks, and again, Sir Sam

click23 · **Joined:** Thu May 11, 2006 9:22 am **Posts:** 308

The NTHSA investigation is now closed.

"THE LOCATION OF THE FUEL FILTER / WATER SEPARATOR ASSEMBLY IS NOT NEAR THE LOCATION OF THE TURBO CHARGER WHICH IS LOCATED ON THE OPPOSITE SIDE OF THE ENGINE. THE TURBO CHARGER WOULD PRESENT A POTENTIALLY HOT SURFACE HOWEVER DUE TO THE LAYOUT OF THE ENGINE COMPARTMENT AND ITS COMPONENTS, DIESEL FUEL LEAKAGE FROM THE ELECTRICAL CONNECTION WOULD NOT LIKELY MIGRATE TO THE TURBO CHARGER. AT THIS TIME, A SAFETY-RELATED DEFECT TREND HAS NOT BEEN IDENTIFIED AND THIS INVESTIGATION IS CLOSED. THE CLOSING OF THIS INVESTIGATION DOES NOT CONSTITUTE A FINDING BY NHTSA THAT A SAFETY DEFECT DOES NOT EXIST. THE AGENCY RESERVES THE RIGHT TO TAKE FURTHER ACTION IF WARRANTED BY THE CIRCUMSTANCES."

This makes no since to me. Looks like someone convinced the NTHSA that the only way that this would be a problem if if the fuel makes it to the turbo??? :evil:

BlackLibertyCRD · **Posted:** Tue Dec 11, 2007 9:46 am

click23 wrote:

The NTHSA investigation is now closed.

"THE LOCATION OF THE FUEL FILTER / WATER SEPARATOR ASSEMBLY IS NOT NEAR THE LOCATION OF THE TURBO CHARGER WHICH IS LOCATED ON THE OPPOSITE SIDE OF THE ENGINE. THE TURBO CHARGER WOULD PRESENT A POTENTIALLY HOT SURFACE HOWEVER DUE TO THE LAYOUT OF THE ENGINE COMPARTMENT AND ITS COMPONENTS, DIESEL FUEL LEAKAGE FROM THE ELECTRICAL CONNECTION WOULD NOT LIKELY MIGRATE TO THE TURBO CHARGER. AT THIS TIME, A SAFETY-RELATED DEFECT TREND HAS NOT BEEN IDENTIFIED AND THIS INVESTIGATION IS CLOSED. THE CLOSING OF THIS INVESTIGATION DOES NOT CONSTITUTE A FINDING BY NHTSA THAT A SAFETY DEFECT DOES NOT EXIST. THE AGENCY RESERVES THE RIGHT TO TAKE FURTHER ACTION IF WARRANTED BY THE CIRCUMSTANCES."

This makes no since to me. Looks like someone convinced the NTHSA that the only way that this would be a problem if if the fuel makes it to the turbo??? :evil:

Look like Chrysler blame the turbo for the thermo event (fire) and not the location of the filter. The spot the fire started may not be where the fire burned the hottest. We where not there so we can not prove otherwise.

gmctd · **Posted:** Tue Dec 11, 2007 10:09 am

It's more likely they took the max temp of the fuel heater @ 85degF and compared it to the avg 650degF turbo temp for the decision - the EGR tube is the only thing on the driver's side with enuff energy to start a Diesel fuel fire, and it's tucked up in its area

And first, you need to prove any fire started at the fuel manager head, which noone has, so far, and then prove repeated incidence of fire from that module - until then, you're just spittin' upwind, right?

chrispitude · **Posted:** Tue Dec 11, 2007 1:11 pm

Welp, I guess now it's time to look into a lift pump. gmctd, I like your stealth in-tank lift pump.

- Chris

chadhargis · **Posted:** Fri Dec 21, 2007 1:26 pm

Well, my fuel heater finally gave up the ghost too.

I was out of town on business and when I went to start my CRD, I had to crank it for a long time. It started and ran for a few seconds then died. I figured it had lost prime, so I pumped the fuel head, and it started right up without any problems.

When I got home, I went to bleed the fuel head, and as I was pumping up the head, I saw fuel bubbling out of the heater plug. I pulled the plug and saw a nicely charred connector. I'll try to post some pics when I get home tonight.

Luckily we're having unseasonably warm weather (65 for the high here), so I unplugged the heater and motored on. I'll be dropping it off to the dealer tomorrow.

BiodieselJeep.com · **Posted:** Fri Dec 21, 2007 3:54 pm

Chad:

You might need to plug it back in in order to get to the dealer. The heater plug actually helps reduce the amount of air getting into the burn-holes! Learned this the hard way....no sealant seemed to do as good a job as the plug, the diesel (and biodiesel) made it really tough to get a seal. And my old plug-a-hole-standby of wine corks won't work in that oval hole. Instead, I'd clip the wires, plug it in and prime it again before you drive. Probably will hold until the dealership.

chadhargis · **Posted:** Fri Dec 21, 2007 4:36 pm

The leak isn't huge. I got to work just fine. I have some silly putty I considered sticking in there. Either that, or heading to Home Depot for some pipe dope.

Since it's sucking instead of blowing, anything that I can shove in there should do the trick. Even considered filling it with JB Weld.

I can drive it like it is, just need to take it to the dealer tomorrow and let them warranty it. I'm leaving for vacation next week and we'll be taking the minivan, so I won't need my Jeep for a week or so.

litton · **Posted:** Fri Dec 21, 2007 7:32 pm

chadhargis wrote:

Well, my fuel heater finally gave up the ghost too.

I was out of town on business and when I went to start my CRD, I had to crank it for a long time. It started and ran for a few seconds then died. I figured it had lost prime, so I pumped the fuel head, and it started right up without any problems.

When I got home, I went to bleed the fuel head, and as I was pumping up the head, I saw fuel bubbling out of the heater plug. I pulled the plug and saw a nicely charred connector. I'll try to post some pics when I get home tonight.

Luckily we're having unseasonably warm weather (65 for the high here), so I unplugged the heater and motored on. I'll be dropping it off to the dealer tomorrow.

Please take a moment to file a complaint with the NHTSA with emphasis on the charred connector as a potential source of fires. Perhaps a pic as well if the website accepts them.

chadhargis · **Posted:** Fri Dec 21, 2007 8:58 pm

Will do. It was dark when I got home tonight, but I'll try to get some pics tomorrow.

retmil46 · **Posted:** Sat Dec 22, 2007 3:53 am

If memory serves, doesn't the fuel heater have a dedicated fuse in the engine compartment panel? Instaed of clipping the wires and having to repair the harness as well, just pull the fuse and plug the connector back in to reduce the leak.

Every time I read another post along this line, I thank the gods that I decided to quit screwing around with that POS factory filter and replaced the whole ball of wax with a decent setup.

chadhargis · **Posted:** Sun Dec 23, 2007 4:37 pm

I snapped a few pics of my burnt fuel heater connector.

This is the connector. You can see it's fairly well charred and this is with me keeping an eye on it. Don't know what caused it as it's been working just fine until last week with no burnt connectors. It appears to come out of nowhere.

This is a picture of after I pumped up the filter head. You can see the fuel bubbling out of it. It's a pretty severe leak.

Here's a shot of the connector on the fuel head. You can see that it's burnt as well.

I'm taking it to the dealer on Wednesday.

I've filed a complaint with the NHTSA

chadhargis · **Posted:** Fri Dec 28, 2007 10:51 pm

Wow! I have the fastest dealer in the world. I dropped my Jeep off the day after Christmas and they called today to tell me it's ready. They replaced the filter head and the filter too. I am guess they replaced the burnt connector as well.

Sadly, I'm out of town on vacation and can't pick it up till Wednesday.

warp2diesel · **Posted:** Fri Dec 28, 2007 11:15 pm

I went to my local Jeep dealer to buy a replacement fuel filter since I have about 9.5K left on my warranty. When I pulled the first connector plug off the fuel heater head so I could fit my hand in there to change the filter, it was wet with diesel fuel. With out my L.O.S.T. inspired add on lift pump, this problem may have not been found out and could have trashed out my CP3 pump. Before I added the lift pump, I would get at least 1/2 oz of air out of the bleeder every time I cracked it open and pumped up the primer once a week or so.
I have also noticed lately, that my engine cranks five or six strokes when I cold start it where it used to only crank two to three strokes. One time when I had to fly out for a five day work related trip, it would not start with out a jump in the O'Hare parking lot . Part of the problem was not trickle charging my Optima battery after discharging it, but the rest of the problem must be related to having the air leak in the fuel filter head that required the engine to crank extra to start.
When I drop my CRD off next Friday for the Warranty fix, I will yank the fuse to my lift pump so it does not run when they drive it in to fix it.

Steve :wink:

SAFETY WARNING: unplug your fuel heater element

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