Fuel Gauge
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Cross-Country
Joined: Aug 2009
Posts: 60
Likes: 2
Fuel Gauge
I don't use my 79 much and it sits in the garage most of the time, I take it to a show every once in a while or sometimes just take a ride out in it. I keep the truck filled with non-ethanol gas to avoid the ethanol problems where the truck sits a fair bit. Yesterday I went to a gas station near me that sells non-ethanol and filled the truck up trying to beat the rising prices. I have two tanks on my truck, the original tank behind the rear axle and an extra side tank I added years ago. I have a selector switch to change tanks and it also makes the gauge register which ever tank I am pulling from. Yesterday after filling up I noticed my main (original tank) even though full has the gauge only registering 1/2 full. Has anyone else had this problem?? Do you think replacing the fuel sending unit in the tank will take care of the problem?? I noticed after looking at a couple of catalogs last night that LMC & NPD both list the sending units or could it be an electrical problem?
Thanks for any replies!!!
Thanks for any replies!!!
Hotshot
Joined: Apr 2009
Posts: 14,333
Likes: 247
From: Stanley, VA
Does it seem to be okay when on the auxilliary tank? If so then chances are it's the sending unit but do a couple of checks first.
Disconect the wire from the gauge at the sending unit and ground the wire. Turn the ignition "on" and watch the gauge. If the needle goes all the way to "full" that will eliminate any wiring problems. Next, pull the sending unit out and check the float. These are notorious for hairline cracks that allow it to fill with fuel and sink. If its partially filled it could be throwing the reading off.
If the float checks okay then it's probably the sender. If the float is bad, these are available separately.
Disconect the wire from the gauge at the sending unit and ground the wire. Turn the ignition "on" and watch the gauge. If the needle goes all the way to "full" that will eliminate any wiring problems. Next, pull the sending unit out and check the float. These are notorious for hairline cracks that allow it to fill with fuel and sink. If its partially filled it could be throwing the reading off.
If the float checks okay then it's probably the sender. If the float is bad, these are available separately.
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Cross-Country
Joined: Aug 2009
Posts: 60
Likes: 2
Reply
Mike
Thanks for the quick reply, I will try grounding the wire to see what happens, as for the side tank, it never does show all the way full on the gauge, usually about 3/4 full. This tank is an aftermarket tank that was added years ago, if the sending unit also needs replacing in this tank I'm not sure where to get one for it.
Thanks!
Thanks for the quick reply, I will try grounding the wire to see what happens, as for the side tank, it never does show all the way full on the gauge, usually about 3/4 full. This tank is an aftermarket tank that was added years ago, if the sending unit also needs replacing in this tank I'm not sure where to get one for it.
Thanks!
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