How do you verify gauges work if they are not in a vehicle? Speedo? Is it possible (ie drill on end of cable?) fuel should just be an ohm reading right? Or is there a difference with the combo guages the 80's have?
The cvr for the oem gauges is inside the temperature gauge pod and jumpers it's nominal 5vdc output to the fuel gauge. Do not attempt to hit the fuel gauge with b+!!!! Even for an instant!
Any mechanical speedometer May tested for function by chucking a short section of scrap cable in a drill motor and spinning it up. But...spool up the drill speed very slowly so you don't "shock" the movement inside in case it's seized.
If...you think the actual temp and fuel gauges are functional and the wiring is correct, then disconnect the fuel sender wire at the center terminal and very quickly ground it while the key switch is in the "on" position and watch for needle movement on the fuel pod. If it begins to move slowly towards full then it's ok but don't do that for more than a few seconds or you will fry the fuel gauge pod. When you remove the wire from ground, the needle will return to emt and prolly bury itself. You can do that two/three times but no more!
To the typical tightazz IH owner/operator...free is too high, they would want shipping thrown in for nuthin' also!
If the two temp/fuel pods are actually functional, then $25>$50 is more than fair. Speedo (if functional)...$25.
From what I can see in the pic, those units are actually in very nice condition comparatively speaking! Those were supplied to IH by stewart warner back in the day.