C cab gas guage

[mbstude]

The gas guage in my '59 PU goes to F when I fill it up, but a few days later it goes to E. It's not out of gas, just the guage doesn't register on anything other than full.
Do I need a new guage? Sending unit? Can the sending unit in the truck be fixed easily?

Thanks in advance,

___________________________________________

Matthew Burnette
Hazlehurst, Georgia
'59 Scotsman PU
'63 Daytona HT

http://mbstudebaker.blogspot.com/

http://thestudillac.blogspot.com/

[Roscomacaw]

Since the gage DOES work to a degree, I'd be thinking sending unit. You can test the unit with an ohmmeter to see if it responds in linear fashion as you work the float thru it's range of travel. Of course, if the wire winding's broke or the little contact arm is worn out (both things I've seen), you might get no reading at all except when the float's held to the "full" position.[}]

Miscreant adrift in
the BerStuda Triangle


1957 Transtar 1/2ton
1960 Larkvertible V8
1958 Provincial wagon
1953 Commander coupe

[John Kirchhoff]

Yep, probabaly time for a new sending unit. Sounds like the resistance wire on the gauge itself has broken a little ways from one end. Once the float is below that point, the guage is no longer getting an electrical signal. There's a possibilty there's varnish and crud on the wire but if it was working ok before, that's probably not it. I'm not sure how a Stude sender is made, but on my motorcycle I had a similar problem. The wire was intact but all the other moving parts had worn enough that the grounded side of the unit was failing to make contact with the resistance wire part way down. With a piece of baling wire (how stereotypical of a farmer) I was able to tighten things up and it works fine. Saved myself several bucks as well.

So you might look it over carefully before going hunting for a replacement. To check it out with a multimeter, set the meter to resistance, attach one electrode to the terminal where the wire goes and the other to any other metal part of the guage like a screw hole. As you move the float arm, the meter should show increasing or decreasing resistance as the arm is moved from one extreme to the other. If the resistance wire is busted, the meter will suddenly drop to nothing or jump up when you're on either side of the broken spot.

[mbstude]

Thanks guys. There may be one laying around here somewhere.
My next queation, do I have to pull the gas tank out to get to it?

___________________________________________

Matthew Burnette
Hazlehurst, Georgia
'59 Scotsman PU
'63 Daytona HT

http://mbstudebaker.blogspot.com/

http://thestudillac.blogspot.com/

[Rosstude]

No, pull the seat bottom, and there is a cover to access the sender.

Ross.
Riverside, Ca.
1957 Provincial X2
1958 Transtar
1963 Lark

[stude freak]

Just go ahead and drop the tank ,Matt ,think of the valuable experience you will get

David Baggett Mantachie,Ms.

[DilloCrafter]

Matthew,

If you can't find a good sending unit lying around, and you don't mind if the one you buy doesn't happen to come from one of our fine Studebaker vendors (I'm putting my arms around my head now, bracing for tomatos that people may throw at me), you may want to get the Stewart Warner universal unit from Summit Racing. You simply use your old unit to help you measure and cut the rod on the new one, but it works the same way as an original. i.e., the pivot is at the top of the tank, not at the bottom like some universal replacements have.

Check this thread, and look about halfway down it for the yellow highlights.

http://www.studebakerdriversclub.com/sdc_forum/topic.asp?TOPIC_ID=3309&searchterms=summit

[img=left]http://rocketdillo.com/studebaker/misc/images/Avacar-hcsdc.gif[/img=left]DilloCrafter

1955 1/2 Ton Pickup
The Red-Headed Amazon
Deep in the heart of Texas

[mbstude]

I think I'll just pull the seat, all I have to do is pick it up. (Non-adsuting seat). I've had to pull gas tanks before and it's not that bad to do, but all the ones I've pulled were empty. [)]

Thanks for the heads up on the SW sending unit, Paul. I think I just found myself a Christmas present. [8D]

___________________________________________

Matthew Burnette
Hazlehurst, Georgia
'59 Scotsman PU
'63 Daytona HT

http://mbstudebaker.blogspot.com/

http://thestudillac.blogspot.com/

[DEEPNHOCK]

Matthew.
Check your grounds first.
Gauges work on a resistance to ground, so a full reading means there is a lot of resistance (infinity?)..
Triple check your gauge to dash ground, your dash to cab ground, your cab to frame ground, and your tank to frame ground
(all considering it's 12 volt negative ground).
Once you have done that, then you can check the sender.
("Betcha it's a ground": Jim Turner 2004)
Jeff[8D]

quote:Originally posted by mbstude

The gas guage in my '59 PU goes to F when I fill it up, but a few days later it goes to E. It's not out of gas, just the guage doesn't register on anything other than full.
Do I need a new guage? Sending unit? Can the sending unit in the truck be fixed easily?

Thanks in advance,

___________________________________________

Matthew Burnette
Hazlehurst, Georgia
'59 Scotsman PU
'63 Daytona HT

http://mbstudebaker.blogspot.com/

http://thestudillac.blogspot.com/

DEEPNHOCK at Gmail.com
Brooklet, Georgia
'37 Coupe Express (never ending project)
'37 Coupe Express Trailer (project)
'61 Hawk (project)
http://community.webshots.com/user/deepnhock

[mbstude]

OK Jeff, I'll see about all that tomorrow. Today I pulled the seat (anyone want some vintage M&M's? [)][xx(]) and removed the sending unit. It looked almost new and checked out OK on the volt meter. I soaked it with brake cleaner and stuck it back in. I also cleaned the connections at the back of the guage. On the way home it went as far past the F as it could. I'll wait a week or so and see if it moves back to the left. If not, then we go to plan B.

___________________________________________

Matthew Burnette
Hazlehurst, Georgia
'59 Scotsman PU
'63 Daytona HT

http://mbstudebaker.blogspot.com/

http://thestudillac.blogspot.com/

[John Kirchhoff]

I don't know about your truck, but at least on the automobiles (at least mine), the more full the tank is, the less resitance the gauge provides. The less fuel, the more resistance. With that in mind, if you remove the wire from the sending unit with the switch on, the needle should stay pegged at empty. Ground the wire and it should go all the way to full. You might remove the sending unit again, hook the wire up and ground the sending unit to the frame or whatever. Then try running the float through its arc and watch the gauge. As I said, I've never had to pull a Stude sender so I'm unfamiliar how they're made. If the resistance wire is exposed, try putting a little pressure in the grounding tab. If the wire is inside of a cup shaped affair, try wiggling the rod back and forth to see if it will make or break connection.

I don't think it's the instrument gauge because if it's an iron vane style meter, it's either going to work or it won't. When it goes all the way to full, it's getting juice and when it drops to empty, suddenly it's not getting juice and the sending unit is what controls how much juice it gets. If you do buy a new sending unit, make sure you get the right style. Low resistance at full tank and high resistance at low tank. Some gas guages work just the opposite. They're the ones that are pegged at full until the switch is turned on, then they drop to where ever level they're supposed to be. Get one of those senders and your guage will work backwards.

[mbstude]

I may or may not get a chance to work on it tomorrow, but if I do, I'll let you know how it all works out.
Thanks again to everyone! [8D]

___________________________________________

Matthew Burnette
Hazlehurst, Georgia
'59 Scotsman PU
'63 Daytona HT

http://mbstudebaker.blogspot.com/

http://thestudillac.blogspot.com/