Oil & Fuel Fuel guage on the blink

[woodlandfarms]

I thought this might be a short, but now I am thinking it might be the float in the tank. It reads when I fill the tank full, but then zeros out when it drops just a bit. Float is staying up so I think it is related to the sensor.

Anyone ever remove their float? I am going to double check the wiring but this looks to be the culprit.

Carl

 

[J_J]

I thought this might be a short, but now I am thinking it might be the float in the tank. It reads when I fill the tank full, but then zeros out when it drops just a bit. Float is staying up so I think it is related to the sensor.



Anyone ever remove their float? I am going to double check the wiring but this looks to be the culprit.

Carl

Carl,

To determine if the float sensor is bad, use an Ohm meter to see if you have a steady reading. Now, rock the tank to move the float a little, or reach in there with a wire or something to move it up or down. I just finished up breaking the float in my fuel pump assembly on my F-150. Everything was going good until I tried to aligned the fuel pump, but I wound up breaking off the float arm. Fuel pump still works, but the fuel gage is reading 1/4 tank and I know I have a full tank. Bummer.

 

[woodlandfarms]

I have an old F-150 and the second tank does not work unless full. Such a pisser. You have to drop the tank to replace the sensor. So I just watch the mileage guage...

 

[J_J]

I have an old F-150 and the second tank does not work unless full. Such a pisser. You have to drop the tank to replace the sensor. So I just watch the mileage guage...

Carl,

I did not drop my tank, I figured out where the fuel pump was located, and cut a hole about 8 in sq in the bed and took out the fuel pump that way. I then bolted a plate over the hole.

 

[ponytug]

It's kinda hard to believe that they don't come that way from the factory, isn't it?

If you have a mostly empty tank, it is pretty easy to put a plywood plate under the tank and just loosen the straps and lower it the 8" or so you need to get in there. On old(er) Fords, I figure if I'm in there for the fuel pump, it's worth replacing the senders, which always seem to attract gunk out of the fuel.

Use JJ's suggestion of a DVOM and check the readings. My recollection is that fuel sensors run at low voltage to limit sparking, but I don't know what the right resistances should be for the PT sender. Anyone know what brand the diesel senders are?

Speaking of gauges, anybody have any tips for defogging the gauges? Mine are clear when cold, and then fog up for the first hour or so of use, before finally going clear again.

All the best,

Peter

Carl,

I did not drop my tank, I figured out where the fuel pump was located, and cut a hole about 8 in sq in the bed and took out the fuel pump that way. I then bolted a plate over the hole.

 

[woodlandfarms]

Just an update on the PT. I forgot the old school trick of checking your wiring on a bad Fuel gauge. I grounded the wiire that connected to the float and up the needle went. So I pulled out the Fuel Sending Unit... The place where the guaging happens is glued shut, so no serviceable parts. I sprayed with Carb Cleaner, and screwed it back to the rod. And over tightened it. The float stopped moving. I loosened the screws a bit and felt I had a solution... I could feel the sensor rubbing on the internal coil (resistor). So, I popped it back in. Wired it all up and it worked for maybe 30 seconds. Oh-Well. I am going to talk to Terry tomorrow...

 

[woodlandfarms]

Just a follow up. $40 for the part. 10 minutes of my time. Biggest thing was I reused the old float as the new float needed to have the rod shortened. Figured I would save that float for a rainy day..

Carl