I just bought a used fuel sending unit for my 88 4runner. Is there a way to test it before I drop the tank? I can get to the connector that it hooks to. Can I just plug it in and manually move the float and watch the fuel gage? The one that is currently in the rig works when you fill it up then after about 70 miles moves to empty.

 

yeah the pluging it in should work, says to use a ohm meter but thats for when its in the truck..