• Swapped out the shocks
• Checked out the rear brakes and bearings
• Installed the correct emergency brake cable on the PS side
  (the Dually came with one cable broken).  It turns out that the cable from the `93 D-250 Extended cab truck worked on the older Dually.    It wasn’t an exact match, but it worked.

I also went in and installed the fifth wheel hitch.  Had to drill the frame but the bed on the Dually already had holes in the correct location.   Wish I could show some photos from the above list, but I was too busy workin’!

OK, now that I’m done with all that (and have no photos), the next step was to work with the fuel tank.

Gasoline tank from the Dually, prior to the diesel swap.

Gasoline tank from the Dually, prior to the diesel swap. Can you believe how much gunk is caked on over the sending unit? I couldn't even see the sending unit head!

The Dually came with a gasoline fuel tank.  It was plastic, very similar to the OE plastic tank on the `93 Diesel D-250.  Photos above.

Here was the fuel tank sender from the Diesel tank out of the D-250. It was in much better condition than the gasoline tank, and yet it still had nearly 300k miles on it!

The Diesel tank and spout was pulled from the `93 during the dismantling process.  Both straps and a protective bracket for one of the frame cross-members were also pulled from the `93.  One problem I had (with nearly 300k on the `93 D-250) is that the fuel tank level was always on E mpty within about 50-75 miles of filling up.  So basically after 3-4 gallons were consumed the truck would show empty, even though I could drive for another 200-400 miles depending on if loaded or empty.  This means an investigation of the fuel tank sender was in order.   At least for a few minutes to see if the resistance values made sense.

Longer photo of the diesel `93 D-250 tank.

The sender is a Carter part.  Surprisingly its made of a lot of plastic.  There are two sender lines, one for level F to E, and another redundant line just for indicating low fuel on the Cummins Indicator panel in the dash.   I checked the resistance at various points along the travel of the float for both lines, as per the photos.

Here’s a text summary of my test results:

Full to Empty side (resistance across Green to Grey wire connections):
Empty -  0 Ohms
1/2 tank – open circuit
Full – open circuit
(Observation - the resistance indication fluctuated from open to NN Ohms throughout the float travel on this line)

This is the fuel level circuit of the sender which gives the reading directly to the gauge on the dash (green and grey wires). It indicated open circuit (no resistance) at full because it had worn out.

Again, open circuit when half full because this side of the circuit had worn out.

A very low resistance reading when the tank is empty, when measured from the tank level circuit on the sender.

Low Fuel Indication side  (resistance across Blue to Grey wire connections):
Full – 9 Ohms
1/2 tank – 83 Ohms
Empty (bottomed out)  -  144 Ohms
Empty (end of track on circuit board) – 132.4 Ohms

This is the low fuel circuit side of the diesel sender - it reads about 9 ohms when the float is indicating full tank.

On the low fuel circuit side of the diesel sender - about 83 ohms when the float is indicating 1/2 tank.

On the low fuel circuit side of the diesel sender - about 144 ohms when the float is indicating a completely empty tank.

Following this analysis, I didn’t have the time to make any fixes to the sender due to the small size of the printed circuit board.  Also, it appeared that whatever wear damage was done between the wiper leg and the circuit board was not easily repairable.  I simply put it all back together and installed the tank back in the truck.   (as a side note, the low fuel indication indeed still works but the main fuel gauge does not).  Someday I hope to swap out or repair/replace the sender unit.

Copyright Kris Wickstead ©2010.  Always use good sense, the proper safety procedures, PPE and safe equipment.  Follow all manufacturers instructions.  For informational purposes only.  Not a guarantee of any kind.  Use information at your own risk.