gas gage doesn't work all the time

[Johns67]

This is werd, ran out of gas and then the gas gage starts working for a couple weeks. Then the needle drops and doesn't work at all. I turned on the key (ignition) and pull the wire off the gas tank and put a test light to ground and the other end into the wire that goes to the tank. The test light is strobbing. Is that normal or has any one found this before? Remember the gas tank is full.
I'm confused!
johns67- is it the wire or the float?

[Jones]

Sounds to me like the float on the sending unit in the tank might have a hole in it. Pull the unit out of the tank and look for pin holes on the float. They can be fixed up with solder or, if I remember correctly, you may be able to replace the float. (Not the whole sending unit, just the float.) Someone chime in if the floats are aslo unattainable.


Keith

[Jeffc]

Your test sounds pretty normal.
It should not have "steady" volts.
Ground the wire at the sender on the tank,
it should peg the gauge to "full".

I agree with Jones, sounds like a sunk
float. Take your float out and take it
to the local ferd (yes ferd)part dealer
and ask'em for a new float. Mopar does
not have them anymore.

If you do solder up the holes, be sure
the float is empty frist
could be fun in closed spaces

One other thing, there is a ground 'clip'
between the sender and fuel line (clip on both
ends of a light metal strap), this needs to
be inplace otherwise sender may not have a
good ground. If clip is missing a short wire
with some small hose claps will work, just
enough to pass over the hose connecton at the
sender/fuel line.

[Johns67]

So far so good. The sending unit wire when grounded shows the needle goes to full. I don't understand the part about the about the ground clip. I don't have one on my truck and looked at another gas (1965-Dodge) tank and it doesn't appear to have it either, but then again that truck hasn't run in 10 years. I just you were trying to tell me how to make another one??? I went to (site)imageevent.
johns67- don't want to pull the float,unless I have to.

[Jeffc]

I will try to get around to posting a photo of the
stock ground clip a little later today; but yes you
can make one your self (above post). They seem to
be often missing, but all these trucks left the
factory (cars too) with them....

Hope you found some of the info helpfull
on my photo page.

Not really hard to pull the sender, unless the
window has leaked and made everthing rusty
(not uncommon to see them rusty from window
gasket leaks)....
seat all the way forward, clean off any rust
present on the top near/on the sender,
pull off the sender wire, pull the hose off,
take a hammer and screw driver and knock the
ring loose holding the sender in the tank......
out it comes...

[Seabee]

... hammer and screw driver ...

Mr Safety says substitute a brass drift for that screwdriver. Although a completely unsubstantiated rumor has it that Mr Safety has performed this operation with both screw driver and with steel punch and has not yet been blown the #%^& up.

[Jeffc]

... hammer and screw driver ...

Mr Safety says substitute a brass drift for that screwdriver. Although a completely unsubstantiated rumor has it that Mr Safety has performed this operation with both screw driver and with steel punch and has not yet been blown the #%^& up.

Smoking is also never a good idea

[Johns67]

I'll wait for the posting of the stock ground clip. I appreciate your time. It will be one more thing working soon.
johns67-have a 65 D-100 with gas tank still in it.

[Jeffc]

I'll wait for the posting of the stock ground clip. I appreciate your time. It will be one more thing working soon.
johns67-have a 65 D-100 with gas tank still in it.

Guess I'm going to make a lier out of myself,
thought for sure I had one on at least one
of my trucks, nope, not one......
unless I get under one of my cars I can't get a
shot.... even look at a few spare senders I have
around......

[WTHETRUCK]

I will try to get around to posting a photo of the
stock ground clip a little later today; but yes you
can make one your self (above post). They seem to
be often missing, but all these trucks left the
factory (cars too) with them....

Hope you found some of the info helpfull
on my photo page.

Not really hard to pull the sender, unless the
window has leaked and made everthing rusty
(not uncommon to see them rusty from window
gasket leaks)....
seat all the way forward, clean off any rust
present on the top near/on the sender,
pull off the sender wire, pull the hose off,
take a hammer and screw driver and knock the
ring loose holding the sender in the tank......
out it comes...

word of caution one removing sending unit you should use a brass punch or something wooden a screw driver could cause a spark

[Johns67]

Thanks!~to everyone the gas gage is working now. It is or was the float that was the problem after all. It had a pin hole in it where the wire that holds it on. Grabbed the one out of the 65 and it's good. I won't know how to act now that the tank will registure how much gas is in it. I bet it has not worked properly for 20 years now. You guys are great.
By the way the ring came off fairly easy, I just used my air chisel. Only kidding!!
johns67-

[Jeffc]

I will try to get around to posting a photo of the
stock ground clip a little later today; but yes you
can make one your self (above post). They seem to
be often missing, but all these trucks left the
factory (cars too) with them....

Hope you found some of the info helpfull
on my photo page.

Not really hard to pull the sender, unless the
window has leaked and made everthing rusty
(not uncommon to see them rusty from window
gasket leaks)....
seat all the way forward, clean off any rust
present on the top near/on the sender,
pull off the sender wire, pull the hose off,
take a hammer and screw driver and knock the
ring loose holding the sender in the tank......
out it comes...

word of caution one removing sending unit you should use a brass punch or something wooden a screw driver could cause a spark

When it comes right down to it, unless you have a
leak, leaving the rubber fuel hose in place when
removing the ring, there "should" be no fumes to spark
till the ring is loose........ but a brass punch/drift
is not a bad idea.
Having done a lot of these rings
over the years (30+), maybe 40+ rings, the wood will just not do the job in most cases, unless it's good hickory or oak, even then if the ring is rusted,
metal will be the only way to get it off.

[Johns67]

Man I feel happy today that the gas gage is working. My son helped me and he is 14 years old. It's great to have people like Jeffc. I am just learning how to use this sight and sights like imageevent really help. One guy years ago told me it wasn't the float so don't waste your time taking it out. The wiring was a mystery to me and until I took the step provided by Jeff. The gas float in the tank had a pin hole and was filled with gas. The hole was right where the wire clip holds the float attached. The werd thing was that the wire going to the tank (with the key on)when tested with a test light, strobbes (lights on and off). The same wire to the tank connected to a ground will peg the gas gage full. Also you must have a good ground and the other wire on the back of the gas gage is hot when the key is on. Thanks!~johns67-on to other things.

[Russ]

John, for your info in the event your are trouble shooting a problem with guages in the future, the gas guage has the voltage reducer/regulator in it. That's why there's voltage on one side and the pulsing voltage at the other side. You will find the same pulsing voltage on the temp sender wire, and the oil pressure guage sender wire if you have an oil guage. The guages don't react fast enough to voltage swings so that's why they don't pulsate up and down with the voltage. Also, trucks with an oil light use a different gas guage than a truck with an oil pressure guage.
I'm glad you got it resolved, I hate driving without a gas guage.

[Jeffc]

Also, trucks with an oil light use a different gas guage than a truck with an oil pressure guage.

That may be true only for trucks that have the electrical
type of oil pressure gauge. That type of gauge was only optioned on the 69 to 71 trucks.

All earlier trucks used mechanical pressure gauge or oil
light.
Basic brake down on the 68 and back fuel gauges>

61 to 64 all the same with ether white or black
face gauges (round gauge plate with flat bottem gauge hole)
http://imageevent.com/jeffc/techstuff/t ... =1&z=2&l=0

65 to 68 black face only (square face plate)
http://imageevent.com/jeffc/techstuff/t ... =1&z=2&l=0

61 to 68 HHP (with tack) or heavy duty set (without tack)
http://imageevent.com/jeffc/techstuff/t ... =1&z=2&l=0

69 to 71 standard with marks on gauges, leters on glass, plastic face plate (there was also a HHP and HD set with round gauges to fit the 69-71 dash)
http://imageevent.com/jeffc/techstuff/t ... =1&z=2&l=0

With the exception of the HHP or HD type gauges
all of the above fuel gauges came with built in
voltage limiters (HHP and HD fuel gauges use extrenal
voltage limiters (limiters= regulators))

[Sandstone]

napa also has new floats. thats where i got mine for my 63.