Fuel tank sending unit - correct ohm readings

rambos_ride

So with a 6v converted to 12v what should the ohms be?

In other words...if I replace the stock fuel tank, what ohm sending unit would I need to order that works with the hudson gauge?

bartibog1

Rambo not sure on this but I have a need for a new sending unit. if you ground the wire on sending unit in my case the guage reads full which would be o ohms full. get handful of resistors and in my case somewhere near 90 to 100 ohms from lead at tank to ground should give you empty.
then you would need one that reads full 90 to 100 ohms, zero would be full . my car is a 53 converted to 12 volt
I also like you had to get my rad recored and sending unit on hold for now just remember to gas up often. your car I am not sure of year but if you do what I did you will get the answer
and buy accordingly.
you can get a good assortment of resistors at radio shack for 5 6 bucks
steve

Glowplug

The attached document should provide all the information necessary to match a fuel guage to a sender.

JasonNC

I bought a Dennis Carpenter Ford sender for my Kaiser thinking that it would work like the one I have on the Hudson. The needle on the gauge never moved. I ended up going back to the original sender that will show empty correctly, but has a tendency to give inaccurate readings from above a fourth of tank. Instead of using the instructions for using resistors for adjusting a sender to an aftermarket gauge, I want to know if anyone out there can adjust the sender unit from Carpenter to match up with my original gauge.

JasonNC

I bought a Dennis Carpenter Ford sender for my Kaiser thinking that it would work like the one I have on the Hudson. The needle on the gauge never moved. I ended up going back to the original sender that will show empty correctly, but has a tendency to give inaccurate readings from above a fourth of tank. Instead of using the instructions for using resistors for adjusting a sender to an aftermarket gauge, I want to know if anyone out there can adjust the sender unit from Carpenter to match up with my original gauge.

bob ward

The only way to have your Carpenter sender read correctly without adding resistors is to rewind the resistance coil. The process of adding resistors will at best make your gauge read accurately at E & F, but it will be off for intermediate readings.

For a good read on how your gauge and sender work, check out the FG series of articles in the link. It is written about MGA electrics (and boy has the author put some work into it) but the principles apply directly to all fuel gauge systems of that era.
http://mgaguru.com/mgtech/electric/electr_1.htm

JasonNC

I have 19-20 ohms at full and 96 empty on the sender. There are no coils to rewind, just a sliding half a circle bar that the arm slides over. Should I try to calibrate the gauge to those settings, if so, how?

Glowplug

Bob Ward, excellent posting!

russmaas

Large paul has the carpenter sending unit recalibrated and sells them