Fuel Gauge = A Big Headache

I have a 1986 Ford Crew Cab 6.9L Diesel which is just sitting in my yard. My bed is off so I could do some frame and tank work to it. I rigged up the tail lights so I can still drive it from time to time but I really want my bed back on the only thing is....

The pickup line on both tanks fell off which I am going to rig up copper tubing into a coil and then flare the ends to connect it to the original steel line and the infamous gauge does not work. I've taken both tanks apart and found my chip on the gauge in the tanks are worn out and have no contact on them. I tried to put 94 chips on it but it didn't work and was told that my gauges are 70 ohms at empty and 10 ohms at full which is why it didn't work. That site I've been told to go to doesn't specify what type of truck or the resistance values of the senders.

http://www.lightdutydieseltruckparts.com/shop.php?c=Performance&n=15728201&x=Fuel_Tanks_Accessories

So I have no idea how to get my gauges to work. I was going to try to put resistors in the lines to match the 94' values but I don't know the 94' values. On the other hand I searched the chip number on the chip and no pictures come up on any of the sites so I'm not sure if its the right one. Any advice....

I'm driving a GMC Duramax in the meantime and I really want that bed on because I'd rather drive my Ford.

got bad news for you.
'87 and up tank sender assys are a completely different animal. Size and OHM resistance readings.
post a pic of what's wrong with yours. I may have a couple of complete 80-86 tanks that I can part with the senders. Pay the ship and they're yours. But be absolutely clear though, There's no guarantee the sender assys work. I have yet to see a older sender work. diesel fuel eats the plating off the board.

JC WHITNEY has a generic $16 sender that is an easy retrofit to our fuel tanks and the gauge will read correctly.

I recently done my forward tank and it works flawlessly.

Here is the TECH article :

http://www.ford-trucks.com/user_gallery/displayalbum.php?&userid=170072&albumid=16937

Hope this helps.

type4 had a link to some dirt cheep parts for the senders but i cant find it now. cost me about $175 in parts to replace the one in my 94 last year

MIDNIGHT RIDER said:

JC WHITNEY has a generic $16 sender that is an easy retrofit to our fuel tanks and the gauge will read correctly.

I recently done my forward tank and it works flawlessly.

Here is the TECH article :

http://www.ford-trucks.com/user_gallery/displayalbum.php?&userid=170072&albumid=16937

Hope this helps.

Click to expand...

You don't happen to have that part # from jc whitney do you?

Thanks for all the help..


Midnight rider, there are two items that I see in JC Whitney that I could use but I would rather not use after market gauges because I would have one really shiny one and the rest stock. Also the tech article that you sent I really cannot see the writing so I am not sure whats going on in that article.

flatlander said:

You don't happen to have that part # from jc whitney do you?

Click to expand...

Here you go :


http://www.jcwhitney.com/autoparts/...Id-100000162409/Pr-p_CATENTRY_ID:100000162409


The price is a few dollars more than I paid, but I am almost 87% sure this is the one.

The "resistance", or whatever, is the same as the factory units.

Pino2234 said:

the tech article that you sent I really cannot see the writing so I am not sure whats going on in that article.

Click to expand...

Click on the link to the TECH article, then scroll down to the "album" of pictures toward the bottom of that page, then click on each picture to make a big picture.

I have no problem reading the instructions that FELLRO typed for each step.

Hope this helps.

Thanks Midnight Rider, I can read what he typed but it was just hard to see that the pictures he uploaded...

So you used this unit and kept the same gauge in the dash and it works good?

Pino2234 said:

Thanks Midnight Rider, I can read what he typed but it was just hard to see that the pictures he uploaded...

So you used this unit and kept the same gauge in the dash and it works good?

Click to expand...

YES, I used the JC-Whitney sending-unit and kept the factory gauge; everything works perfect, actually much better than the factory set-up, as I did some very careful measuring and positioned/bent the float-rod, such that I get a much more accurate range of fuel-depth, i.e. E is much closer to actual EMPTY and F is much closer to actual FULL, no driving a hundred miles before the gauge quits reading FULL.


This is a far superior unit than the cheapie one that Ford used and charges a fortune for.

It is much better designed and the FLOAT is not gonna sink or come off inside the tank, like I have had happen before; there is a loose float riding along inside my rear tank that I couldn't find/fish-out.

It is a simple matter of removing the old junk and carefully following the write-up, adding spacer-bushings to space the Whitney sender such that it does not interfere with the factory mounting.

I did it right on my first attempt.

I also used a couple of framing-squares and a clean straight stick of wood (as a measuring story-stick), in order to correctly position the float and bend it's arm.


One other thing :

If I had the dis-advantage of a factory sheet-metal bed above my tanks, I would carefully cut generous trap-doors above the tank-openings for easy access.


I had much rather have a ragged hole in the bed-floor with access to the tanks, than a shiny scratch-free bed-floor that no one will ever look inside.

midnight--aint that a fact. Youd thought the fact could have done a better job on the gauge settings-----------

MIDNIGHT RIDER said:

JC WHITNEY has a generic $16 sender that is an easy retrofit to our fuel tanks and the gauge will read correctly.

I recently done my forward tank and it works flawlessly.

Here is the TECH article :

http://www.ford-trucks.com/user_gallery/displayalbum.php?&userid=170072&albumid=16937

Hope this helps.

Click to expand...

I know I keep asking you questions but the last picture in this tech article doesn't seem necessary. My tank selector is working properly why would I need to do any of the rewiring. Did you follow the last step or no.

Pino2234 said:

I know I keep asking you questions but the last picture in this tech article doesn't seem necessary. My tank selector is working properly why would I need to do any of the rewiring. Did you follow the last step or no.

Click to expand...

I am not sure exactly what he is accomplishing with those relays.

I did not mess with any of that.

I simply spliced the wires INSIDE the tank, leaving the factory gauge-plug intact; the instructions to do so should be in the write-up.

Here is a lengthy article on tank senders :

http://www.thedieselstop.com/forums/f31/fuel-tank-sending-unit-fordparts-com-66196/

And another :

http://www.thedieselstop.com/forums/f31/universal-sending-unit-122300/


Any more questions, just fire away; that is how we learn.

Those relays were set up to change the polarity for the tank switch. Basically, they reverse switch by switching the ground and positive. They don't have anything to do with the senders other than that. The relays were done on a truck that had been a fuel injected gasser, so the proper wiring for the selector valve was not there. I did that on a 460 truck that now has a Cummins in it. Doing it on a factory diesel, those relays are not a needed item. The pics didn't upload as well as I would have liked anyway...

I've been watching this thread with great interest. I'm getting ready to do some fuel tank work, and even at $34.00 each those universal senders would be a great bargain if you could deep six those crappy, crappy factory senders. Even my new one in the rear tank reads empty with close to 7 gallons of diesel left in it. I always say they're not real gauges more like guidelines. So how hard is this mod really? I actually didn't see Fellro's article just the pictures which I really couldn't read either. Thanks guys,
JD