Fuel sending unit, no specs, which gauge?

So I bought a fuel tank for a 68-7? Chevy c10 off LMC. Came with the sending unit. I reached out to LMC truck to get the specs on the sending unit they sent so I can find a gauge to accurately read what fuel level is.
They said " I did not have specs available for sending unit 32-4057 other than it is for gas tank 32-5980.
Best Regards"

What?! Really?!
[S[S[S

That's like selling a car and not knowing what kind of fuel it takes.

So......... Can someone instruct me as to how to go about figuring out what this things provides for signal?
I'm fairly good with normal electrical stuff, but this ohms stuff confuses me.
I do have a millimeter just don't know how to set it up to read and understand whatever it is I'm reading.

Your sending unit should read from 0-90 Ω (Ohms)

To check with your multimeter, set it for 2000Ω ... or whatever your lowest Ω setting is... one lead to ground/housing/tank, the other to sending terminal. Empty should be 0, full should be 90.

Carefully roll the tank over, if you don't want to remove the sender. (That's what I'd do, 'cuz I'm lazy and like fast results. )

.

OHMs Full Empty

GMC 1964 or earlier 0 30
GMC 1966 and later 0 90

- hop.classicinstruments.com/fuel-sending-units

Dr Crankenstein said:

Your sending unit should read from 0-90 Ω (Ohms)

To check with your multimeter, set it for 2000Ω ... or whatever your lowest Ω setting is... one lead to ground/housing/tank, the other to sending terminal. Empty should be 0, full should be 90.

Carefully roll the tank over, if you don't want to remove the sender. (That's what I'd do, 'cuz I'm lazy and like fast results. )

.

Click to expand...

IronRat said:

OHMs Full Empty

GMC 1964 or earlier 0 30
GMC 1966 and later 0 90

- hop.classicinstruments.com/fuel-sending-units

Click to expand...

Nailed it!



Thanks guys!
I suppose I could have saved both of you the trouble and did a little searching.
Oh well, thanks anyways!