74 amx fuel sending unit

Anybody?

A while back i did a thread on the resistor board. Mine had over 125k miles of use, when it was pulled and was as accurate as my 73 back in the 80s.

I pulled the tank and sender, even though I had no issues with it when I garaged the car for strip down. I am glad I did, to see for my self.

If you have the original sender, you can remove the resister board, but be careful, as the wire wound around it has no provisions to stay in place, other than the slots it fits in.

I recommend gluing both edges along its length, to keep the wire from moving, and assist in proper winding spacing at the ends.

You can install with the unused end facing the wiper arm, it's a mirror copy in resistance, to keep longevity.

Carefully clean it, from any varnish residue.

You may need to bend the float wire to conform to the proper angle and level of the original float, before installing.

Edited by 304-dude - May/11/2021 at 4:07pm

I still have my original sender somewhere in the garage.

I can make measurments once I locate it. Float angle at rest and its drop from pivot. The wiper arm is part of the float mechanism, i think there are stops to limit how far the float travels in either direction.

As for resistor compensation, a large valued resistor is required to run parallel to lower the ohm value of the after market sender.

I don't know the ohm reading of the after market sender. Once you obtain it you can ohm the resistance at rest (empty) and at full. There may be a limit to how accurate it can be adjusted. Example, either full will be accurate or empty, depending on which side of the scale you choose to adjust. You may be lucky with both ends being a good match for equal adjustment, with out tweaking the upper or lower limit of the wiper and float arm. In doing so, you could make the reading act a wee logarithmic, with a slow decline within a short range on top or on bottom of scale.

I prefer to have it close to original for an empty reading. Which should bring the needle just under the lower corner of E. At least for my 71 and 73 Javelins when I had driven them.

Edited by troutwilly - May/11/2021 at 9:32pm