Wondering Fuel Guage

[Trevor]

The sender unit consists of a float, lever and variable resistance incorporating moving a contact, along the usual lines. Obviously the sender is subject to problems involving faulty contact points, due to normal wear and tear.

The good and reassuring thing is that the warning light is controlled via a solid state thermistor, which should remain reliable. However it should be noted that this does not provide a warning until after the ignition has been turned on for 3 - 4 minutes.

[NeedForSpeed]

Originally Posted by Trevor

The sender unit consists of a float, lever and variable resistance incorporating moving a contact, along the usual lines. Obviously the sender is subject to problems involving faulty contact points, due to normal wear and tear.

The good and reassuring thing is that the warning light is controlled via a solid state thermistor, which should remain reliable. However it should be noted that this does not provide a warning until after the ignition has been turned on for 3 - 4 minutes.

Thanks Trevor, I didn't know about the thermistor
Which side of the tank is the thermistor, and which side is the sender unit with float that records fuel level on the gauge?

[Trevor]

Originally Posted by NeedForSpeed

Thanks Trevor, I didn't know about the thermistor
Which side of the tank is the thermistor, and which side is the sender unit with float that records fuel level on the gauge?

Both are combined with the pump as a single assembly, situated in in the upper rear of the center section, of the saddle type tank. The assembly comes out through the top of the tank as one unit. There may be details in the how too sections.

[legacyau]

Can the g force from cornering make the fuel slosh from side to side over the hump in the tank and thusly affect the reading, higher or lower until it equalises again?

cam

[NeedForSpeed]

Originally Posted by Trevor

Both are combined with the pump as a single assembly, situated in in the upper rear of the center section, of the saddle type tank. The assembly comes out through the top of the tank as one unit. There may be details in the how too sections.

Hi Trevor. If I remember correctly, the right hand assembly must be 'snaked out' first. This unit drops down into the bottom of the right side of the saddle tank. Then, the left side assembly is removed, it drops down into the bottom of the left side of the tank. Both sides have floats. For the sake of this thread and those needing repair, I was wondering, which side of the saddle is the float and sender, and which side is the float and thermistor that turns on the lamp? Or, are these on the same side, and there is a float that sends info to the jet pump? thanks

[RojoRocket]

Ron,
Not presuming to answer for Trevor, but iirc the pump resides in the left side of the tank, where the thermistor must also reside, if it's truly to deliver the "last word" on the fuel status, ignoring the signal from one or both faulty float readings. The jetpump is just a "dumb" pump driven by fuel flow from the fuel-pump(thus it's name) to continually transfer fuel from the right side to left. I'm certain I'll be corrected if wrong.

Glenn

I'm surprised you don't remember this after our last "fume inhaling" exercise in my garage.

[RojoRocket]

Originally Posted by legacyau

Can the g force from cornering make the fuel slosh from side to side over the hump in the tank and thusly affect the reading, higher or lower until it equalises again?

cam

I wouldn't think this would fubar the readings as there must be some kind of "averaging" circuit in residence to deliver a reading "between" the disparate float resistances. You do, however, bring up a good point regarding the forces working on these float assemblies that explains their degradation over time. Again, I wait to be corrected.

Glenn

[NeedForSpeed]

Originally Posted by RojoRocket

Ron,
Not presuming to answer for Trevor, but iirc the pump resides in the left side of the tank, where the thermistor must also reside, if it's truly to deliver the "last word" on the fuel status, ignoring the signal from one or both faulty float readings. The jetpump is just a "dumb" pump driven by fuel flow from the fuel-pump(thus it's name) to continually transfer fuel from the right side to left. I'm certain I'll be corrected if wrong.

Glenn

I'm surprised you don't remember this after our last "fume inhaling" exercise in my garage.

Hi Glenn, sure, I remember . Just thought someone else could benefit by reading the details here. I'm not the guy for the last word on this