Is there a way to test a fuel sensor before it's installed? I got a used one and I don't want to go through the hassle of installing it if this one doesn't work, either.

 

With a DMM check the resistance across both ends of the cylinder on the arm that goes up into the fuel tank. Resistance should change as the cylinder is warmed and cooled.
I think?

 

What year is your SuperHawk? 2001 and after have a sending unit for a fuel gauge, pre-2001 have a thermistor as xeris describes for a fuel light. Here's a link to a how-to for replacing a bad thermistor in a pre-2001 bike. This should help your understanding if you have a pre-2001 bike. If you have a 2001+, not sure, but the service manual may have a procedure to test the sending unit.

https://imgur.com/gallery/Mcpbh9C

 

I saw that article and that's going to be my next step if my used one doesn't work. I also saw something where a mustang has the same setup and you can steal the whole can. I figure I can safety wire the mustang can next to the Honda one.

I posted about this on an electronics board and a guy over there said I ought to be able to put an ohm meter on it then warm it with my hand and see the resistance go down.

 

Yes, that's what xeris said.

 

You're right I missed that.