Fuel gauge check

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ram250098

ram250098

69 Barracuda
Joined
Nov 25, 2007
Messages
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Location
Cookstown Ontario Canada
I hope an electrical guru can shed some light here. I grounded my gas gauge and it went to fuel. I put a test light on the wire near the tank and grounded it and got pulses of light. With the ignition on the gauge moves about an 1/8 inch. I put 5 gallons in the tank and it still only moves a shade.
What am I missing?
Thanks
AL
 
ram250098 said:
What am I missing?
Thanks
AL
Click to expand...

Maybe the fact that your sending unit is shot? LOL
Grounding the sender wire and getting a full indication on the gauge means the gauge is working fine. The pulses of light on the test light means the regulator on the instrument panel is working fine. Addition of fuel with no change in the gauge reading means that the sending unit is shot. Replace it.
 
If you have a lift you don't even need to drop the tank. The rear end will sag far enough down to let you remove and replace the sender. The only hard part of the job is getting the retaining ring off. I use a hammer and brass drift to remove (no sparks). Just tap it around until you can unscrew it by hand. Replace the ring the same way, just remember to grease the rubber ring so it will not be pushed out and cause a leak. Also be careful with the metal strap that bridges the short rubber hose that connects the fuel line with the nipple on the sender. You need the strap for the gauge to work since it is the ground for the sender. Needless to say, this is a lot easier and less messy with an empty tank. Can you say siphon hose?
 
Thanks for the info. I don't have a lift but maybe I will send it down to my Mechanic, what dop you figure an hours job? If not removing the tank.
Thanks grump
AL
 
When dropping the tank low enough to get at the sender do I need to do anything to the filler neck or is there a bit of give .
Thanks
AL
 
It can be done by raising the right side of the car and removing the right rear tire. I did it twice this year. Don't forget to use a jackstand.

Also, make sure your fuel level is below the sending unit level or you'd better have a big pan to catch the gas.
 
I just called a parts place that I deal with and they say I am looking at $195 for the sender and gasket and lock ring because the gasket only come with the ring.
Has anyone tried the ebay senders? they seem to come complete with everything for around $100.
Thanks
AL
 
ram250098 said:
I just called a parts place that I deal with and they say I am looking at $195 for the sender and gasket and lock ring because the gasket only come with the ring.
Has anyone tried the ebay senders? they seem to come complete with everything for around $100.
Thanks
AL
Click to expand...

I bought a 5/16 sender from a ebay seller . 65 bucks, with gasket, works fine.
 
Brian, that is the exact one I am looking at, It will be about $100 to my door Canadian. Still better than $180 up here at a parts store.
I think I will try it in my garage with a floor jack. If I jack up the right side and remove the rear wheel will I still have to lower the tank as well?
Thanks very much Guy's
AL
 
You may have to use your old lock ring in some cases. I installed a new sending unit and the new lock ring would not hold gasket tieght so I used old one again and it worked fine.
 
dusterny said:
You may have to use your old lock ring in some cases. I installed a new sending unit and the new lock ring would not hold gasket tieght so I used old one again and it worked fine.
Click to expand...

Same same. I noticed the new lock ring was too thin. Never even tryed it. Reused the original with the new seal. No problems.
 
i buy alot of parts from rob426...nice guy..fair price and sends parts right out...I just bought that same sending unit...nice part...on the install...i was able to remove my sender(72 duster) by just sliding under the car...its tight but came out without removing anything...it was easy to empty the tank....i have an electric fuel pump.....
 
Hey guys, I had mine replaced and after I drive 50 miles, the gueage reads 1/2 full! This was a sending unit that my mechanic found not the ebay one. Is there something wrong with the unit?? This is actually the 2nd unit he put on. They both go to the empty line way too fast. Tom
 
Before I buy it I thought I would try the ground trick on the hose from the tank. I grounded it out to the exhaust pipe and checked the gauge...it went to 1/4 tank, yeehaw It works. So I ran the wire into the trunk and grounded it to the rear seat support. I checked the gauge to make sure it works and it just move a hair??????I moved it to as different spot and still only move a hair, getting POed I ran it to the exhaust again and it only moved a hair...what gives..
AL
 
There should be metal fuel line from the sender to the carb which would supply a ground if it weren't interupted by a 3 inch piece of rubber hose.
The factory simply installed a clip on metal jumper from one metal line to the other.
You can creat a substatute jumper with a piece of wire ( flat wound or braided bare copper is best ) Held in place with a small screw clamp at each end.
Use an ohm meter to verify zero resistance from sender body to any chassis ground point. Once the ground is out of question we go back to " Sender or gauge ? "
 
Thanks Red, that is what I did. I just find it odd that the gauges reads a bit. When it was at quater I added fuel via a jerry can to see if the needle would move and it didn't. Maybe I will ad more fuel and see if it will budge off the 1/4 mark.
AL
 
ram250098 said:
Thanks Red, that is what I did. I just find it odd that the gauges reads a bit. When it was at quater I added fuel via a jerry can to see if the needle would move and it didn't. Maybe I will ad more fuel and see if it will budge off the 1/4 mark.
AL
Click to expand...

OK, so lets assume the ground is sufficient. Short the sender wire to ground and turn the switch on. If needle races to 'F' in a smooth motion. Turn the switch off and replace the sender.
If the needle should do anything different , the gauge or its power supply is at fault.
 
Well back to square one again...guess I will have to bit the bullit and buy a sender, thought I had a small glimmer of hope there for a second LOL.
Thanks again Red
AL
 
I am going to install the new sender on Friday, is there any tips before hand I should know. On guy said a bit of grease on the ring, is this common. The instuctions said nothing about sealants.
Do you guy's put anything on the gasket?
Thanks
AL
 
A little dab of lubricant (Vaseline, ATF, KY, grease), just enough to coat the O ring, will let the sender slide instead of grab the O ring when it tightens down and prevent a leak. If the sender grabs the O ring it will bunch up and you will have a gas leak at the lock ring. The sender will twist a bit when you tighten the lock ring no matter what you do.
 
ram250098 said:
I am going to install the new sender on Friday, is there any tips before hand I should know. On guy said a bit of grease on the ring, is this common. The instuctions said nothing about sealants.
Do you guy's put anything on the gasket?
Thanks
AL
Click to expand...

I agree that a bit of lubricant is in order but not a gasket sealer. Some of the aftermarket gaskets are a joke and are too thin as are the retainers so shop carefully. Watch out for junk made in China!
 
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