Fuel Tank Sending Unit: Old

[IDave]

Sooooo, apparently the 65 and earlier fuel sending units, and their fuel level gauges, are opposite the later ones. SOR lists the sending units as different, and the gauges as the same, but.....

I tried switching meter gauge boxes for my '45 with one from a '72 '40 that I ravaged, to get a working speedometer/odometer. On the fuel gauge, though, full is empty, and vice versa.

Tried switching the leads. That didn't work.

Is that the issue? I pulled the old gauge and switched it into the newer instrument cluster. It works, but it is marginal. Both gauges look the same, but the old one does the right thing, when it works.

Any thoughts? Should I get a newer sending unit to match the gauge? Or look for an old cluster and hope it has a better fuel gauge? I like knowing if my tank is full or empty.

 

[IDave]

Uhh, in the hopes that there is a knowledgable person here on this, and it was just missed due to the system going down last week, I am sending it to the top for another try. *grins*

 

[Landpimp]

Dave, sorry I just don't know

Mark I bet will know.

 

[TJDIV]

I'm having a bitch of a time with my fuel gauge as well. Between the two grounds and the trouble shooting clips...who knows.

I'm about to go to NAPA and get an aftermarket gauge to try that (my dash unit might be shot...but doubt it) or I'll have to replace the SU.

Don't know the answer to your troubles, but am feeling your pain.

 

[Romer]

Dave,
When I bought a cluster to get an oil gauge, they guy sent me two clusters one like my 77, and another "older one" Don't know how old it is. If it is what you need, you can have it (Fuel gauge)and I won't even make you flip your bezel.

 

[Landpimp]

FWIW, the early clusters have no printed circut boards, not sure when they started using printed.

 

[Romer]

One cluster has the printed circuit board like in my 77 and the other has metal on the back. Don't know if its got a board inside.

 

[IDave]

Ken, I'd love to have that fuel guage to try. This one is driving me nuts. It seems to work when I start up, then click, it is off. I ran out of gas yesterday driving down the highway (I keep a 5 gallon container in the back, so no prob). It is just goofy.

I've never seen a printed circuit board on a cluster. You guys with your newfangled trucks....

 

[Romer]

e-mail me your address and I'll try and get it in the mail tomorrow. If I remember, the face on the gauge isn't as pretty as it should be. Nothing white paint and a steady hand can't fix.

Is the fuel gauge the only thing you need?

Ken

 

[Owyhee Jackass]

Dave, I will look at my box of gages and see what I have.

Are you sure you have a good ground on your old one? If I have a fat-ass in my 63' passenger seat (if I let my wife drive and I'm shot-gun) my gas gage stops working...sometimes. I think it has to do with the ground.

 

[IDave]

Well, I do wonder about the ground. I fiddled with it a little when I took the gas tank out to remove the squirrel's nest and ammo from that thing in the back, but I'll try cleaning it up a little more.

 

[Poser]

FWIW, the early clusters have no printed circut boards, not sure when they started using printed.

09/73


Good luck!


-Steve

 

[Romer]

Don't know if this will help date it, but the older cluster has the fuel gauge on the right, whereas the newer cluster has the gauge on the left.

 

[Landpimp]

all my early stuff(up to 67) is Oil/fuel/temp/amp

82's are Oil/Fuel/temp/amp

got a real old fj25 or early 40 that has idiot lights for oil and charge, only temp and fuel guages.

 

[IDave]

Well, there's something more than that going on, because the cluster from my 65 is the same as the cluster from my 71 and the same as the cluster from the 72, as far as the "Oil/fuel/temp/amp" pattern. But, as I said, the gauge that came with the 65 rises toward "F" when the gas tank is filled, and the gauge from the 72 moves to "E" when it is full, moves to "F" when it is empty.

 

[Landpimp]

how about using the sender out of the 40 you took the guage from? or did you try this.

also, how about checking the ground, just run it to a known good ground

or use a yard stick and dip it in the tank

 

[IDave]

Maybe that is the thing. Grab that old sender. But are the tanks the same? Will that work?

Putting the yardstick between the passenger's legs may result in some unintended consequences!

 

[Landpimp]

my gut feeling is yes they are the same(or close enough), the tanks are slightly different but just in the shape I think, bet the sender from the 72 fits fine in the 65. I would really check the ground 1st.

I wont comment on the yard stick..........but man to I want to

Maybe that is the thing. Grab that old sender. But are the tanks the same? Will that work?

Putting the yardstick between the passenger's legs may result in some unintended consequences!

 

[65swb45]

I'm with Owyhee Jackass on the ground theory. The three guages share a common hot lead and only differentiate by their individual grounds. The first thing I would do is run a different wire from the ground terminal side of the guage to the sending unit and see what happens.

Also curious if the guage is staying within the limits of the readable area at both ends or if it is 'pegging' off the end at one or both ends?

 

[IDave]

I'll try playing with the ground. Yes, the gauge drops off the bottom end. When the power is off, or when it isn't working, the indicator goes well below the "E". When full, the gauge never read more than 3/4.