38 Gallon Fuel Tank Sender Option

Quick set of words about the Spectra FG33C sender that I put in my Spectra 38 Gallon tank.

Short version: It works

Long version:

I'm working on my 1994 with a flatbed and conveniently a gooseneck hitch/door that puts me right at the sender.



It is a sender made for the OBS (and maybe '87 and up??) gas trucks. It has 4 prongs instead of two; two are for the sender, two are for the gasser in tank fuel pump. Pay no attention to the two extra plugs for the pump. You don't need em on your diezel truk. The plastic surrounding the plug seeds to be massaged so the 2 prong plug can fit. One of those fuel pump prongs also need to be cut.



Bracketry exists for that aforementioned fuel pump; ignore it, you dont need it.

Take the float arm off and do your best to make it read F to E in this massive tank. Without making a new arm success may be limited, but you can get close with what was provided.

"Duck Bill" red rubber thing on the return line will likely hit your float sender arm if you choose to bend yours like I did. Use some common sense, cut the 90 degree bend off the tube and make it not hit.



I used Gates 27097 submersible fuel line with a brass barb on the end to get to the sump in the tank. It fit perfectly, the barb was sitting right in the indented sump with no modification.

Other than plugging it in and installing the lock ring etc thats about it. Surprised me with how easy it was. Took maybe an hour, and admittedly this is my first time ever doing one.

More pics: I got my tank out of a 1986 parts truck so it had a bullnose style sender that the previous owner had put together. It read my 1994 gauge backwards . But it gave me a great idea on what geometry I needed to have to get the pickup and float close to right.

Nice job, I used a bronco tank in the dually and modded the tube from the old pump line with steel then a short piece of nylon air brake tubing heated and pushed over. Cut to length and done.
I should took pics.lol

Make sure that red duck bill flapper valve is on the return line. That is an anti siphon valve for the returns. Also on the suction line there is another valve. That is there in case you have frozen water in the bottom of the tank. This valve will allow you to suck diesel to run.

Update, running the tank until it had bottomed on E and I had used 31 of the 38 gallons. Not bad for not making a new arm. It stays F for probably 75-110 miles before moving like it should through the range. I'll take it

a couple pieces of tech i learned on this swap as well.

you can purchase a new clip from any auto store for the EFI truck that will clip into the top of the sender.

take your 2 wire pig tail (for diesel truck, since our riggs dont require a in tank pump)

use a pick in the back part, and you can get the stock connector out of your "pig tail plastic clip"

the connector and the seal come right out.
simply install into the 4 pin plastic clip, and be golden!

we purchased a new shower head from ford.
for the tune of 45 bucks.
thats what we get for not ordering the 17 dollar part off e-bay.

List:

As an alternative using a new short version sender for repair:

In many cases the portion of the new sender actually needed is the "circuit board" inside the plastic box and perhaps the wiper. The box can be carefully removed from its steel base (for both new and old senders) and the new parts swapped into the old sender. The sense wire would need to be soldered to the new "board". Check carefully for right vs. left handed mechanisms and test for proper F and E ohms before you begin. I have successfully had these plastic boxes apart and back together again. Good luck.

Regards,