Fuel Level Sending Unit Broke--Fix?

[MAYoung]

On to the next subject. I will try and be brief.

1) The fuel level sending unit located in the fuel tank is erratic. It has been a common problem for these trucks, I am told, as the float lever wears a "spot" on the contact. The unit measures correctly and then suddenly drops to zero. To deal with this, I try not to let the tank fall below half full.

2) Dodge no longer manufactures or sells the replacement part for this sending unit. Their solution is to sell you the in-tank fuel pump which has new fuel level electronics. (When you see a replacement part for the worn sending unit, it is the part that goes with the in-tank fuel pump.)

3) I have a FASS DDRP installed in the truck and it has been there for the better part of 10 years. It works for the truck in both starting and running. Lowest pressures I see is arouind 12 psi when towing on a grade. Average is about 13-14 psi. (When the pump was new, I saw about +2 psi in all operations.)

4) I could pull the FASS DDRP and rely on the in-tank pump for fuel pressure. Put how big would the drop in psi be? When the in-tank pump fix came out, people reported satisfactory operation. Now I read in TDR less than stellar performance.

If anyone has a way to repair the old fuel level sending unit, I am all ears. I would like to keep the truck as close to stock or recommended Dodge repairs.

 

[MAYoung]

I checked my records. I installed the FASS DDRP in January 11, 2011 so it has been working, trouble free, for the last eight years. As I mention above, the pressures have declined a few psi but it actually starts easier with the somewhat lower pressure. Nothing dramatic but it characteristically has a one-touch-of-the-key start.

 

[fest3er]

Carefully put a 'v' in the sweep arm to shorten it. Change it from '-------' to '---^---'. Bend it slowly and gently, not quickly and sharply; you don't want to weaken or break the copper arm.

I bought a '97 Carter unit from a local parts store and swapped pieces to my '98's unit (metal parts on top had rusted away). Since the '97 uses a different resistor plate, I had to re-use the old one; I also re-used the old arm as well. So I put a 'v' in the arm as described above. It's still OK at least 7 years later, although I think there was a bit of non-linear operation above 7/8 tank a couple weeks ago. So it *might* be getting ready to start going south again; but it'll take more than a few years to be too annoying.

You *might* be able to find a parts store that can source a fresh Carter unit for your '98.

 

[NIsaacs]

Will any of this work? https://www.genosgarage.com/category/fuel-tank-components

Your thread here that you seemed to ignore, a lot of good info: https://www.turbodieselregister.com/threads/fuel-gauge-sending-unit.265695/

 

[MAYoung]

Found my old thread from January 2019. I will contact Geno's and see what part the sending unit part represents. I will let you know what I find. Thanks.

 

[MAYoung]

I just spoke with Geno's Garage tech people. They claim that they do have a Mopar replacement fuel level sending unit for my truck. They list it in their catalog as P/N 4897668AF.

Now they did not have one on their shelf at this very moment but they are expecting a Mopar shipment tomorrow. I will cross my fingers and hold my breath until confirmation of shipment. The only downside is the price---$439.00. But if I can get this one to last 20 years, I can amortize the price at $20/year.

I could probably go a long time without a fuel gauge but if someone else is driving the truck, they may not know the fuel quantity. So, I am going to do my best to fix this problem.

 

[DavidC]

I am starting to wonder what the deal is now. That PN corresponds to 98-02 yet they list a seperate sending unit for 00-02. I thought I read there were differences in resistance or something. Really getting confused now.

 

[MAYoung]

Dear DavidC:

I am not fully sure of all applications. I believe that the difference is that the 98-02 module is not a pump, just plumbing for fuel and a level sending unit (float). The newer unit (00-02) is for the unit that holds the in-tank fuel pump.

Now, the float mechanism that Geno's Garage sells fits on to the unit that is the in-tank fuel pump. However, it also fits on the 98-02 fuel tank module and sending unit but you have to buy a new module for it to work. The float mechanism will not fit/work on previous modules (or the broken one in my tank); you have to buy a whole new module even if it is not a pump. That is what I am doing.

I originally was attempting to just find a new float mechanism and I was told it was not available except for the newer pump-in-tank models. I did not realize that the entire sending module/float assembly is available--at a price.

Anyway, that is what was explained to me. I think that unless you are looking to repair your older sending unit, it is hard to get into the weeds on this one. Nuclear physics is a bit easier than trying to figure out why Dodge does some things and not others.

I

 

[Bill Lins]

Nuclear physics is a bit easier than trying to figure out why Dodge does some things and not others.

Sometimes I question if even Dodge knows why...

 

[NIsaacs]

Dear DavidC:

I am not fully sure of all applications. I believe that the difference is that the 98-02 module is not a pump, just plumbing for fuel and a level sending unit (float). The newer unit (00-02) is for the unit that holds the in-tank fuel pump.

Now, the float mechanism that Geno's Garage sells fits on to the unit that is the in-tank fuel pump. However, it also fits on the 98-02 fuel tank module and sending unit but you have to buy a new module for it to work. The float mechanism will not fit/work on previous modules (or the broken one in my tank); you have to buy a whole new module even if it is not a pump. That is what I am doing.

I originally was attempting to just find a new float mechanism and I was told it was not available except for the newer pump-in-tank models.

I replaced my sending unit with the (00-02) unit. It was an exact fit for my '01, non fuel pump module. If you can afford to have your truck down for a week or so, I would pull the module and see what you have. The (00-02) might work. Dang, $400 is a bunch if all you need is a sender.

 

[MAYoung]

Dear NIsaacs:

Thank you for the tip. I agree that the price tag for a non-pump module is high at $400 but I have taken the plunge and ordered it anyway. It will be here on Monday, May 6th. I will take pictures of the change-out process and post them online here. My hope is to have a working fuel level gauge and no more dinging of the chime as the needle bounces around erratically.

As I keep cars a long time, my first rule of ownership is that everything works inside the cab---all the lights, chimes, switches, heater, A/C, etc. Its just a personal thing of mine. (Most people can get by with less until a new truck arrives.)

 

[NIsaacs]

This appears to fit: https://www.genosgarage.com/product/dodge-diesel-vulcan-performance-fuel-module-MFM20e/new-products

 

[mfurrh55]

This appears to fit: https://www.genosgarage.com/product/dodge-diesel-vulcan-performance-fuel-module-MFM20e/new-products

I bought one like this for my 01 but it had the intank pump with it for 400.00 , I was replacing the lift pump on engine, never had any trouble out of it