How to find out which oem gauge is more accurate ?

[Racer57]

My tach died so I have the instruments out. I have a spare set of stock gauges from an extra cluster. So I have 2 each of gas, water, alt(I know) and oil. Is there a way to find out which is the most accurate by bench testing ? The ones that were in it appeared to be ok but I have nothing to compare them too.

[Racer57]

Come guys, theres got to be at least one of you with an answer. 

Better than saying "bump". 

[dodj]

Well, in order to see which one is the most accurate, you would need a variable resistor (pot) and know the range of the sender. Like the gas gauge is 10 ohms to 70 ohms. So hook up one gas gauge with the  POT and set it to 10 ohms and see where the needle sits. Should be on the 'E'. Then set the POT to 70 ohms and see how close to the 'F' mark you get. Do the same with the other gauge and see which one hits the marks best. Same with the water and oi. Except I'm not sure what the resistance range of those ones is offhand. Maybe someone will have the values for you and post'em up.

[MrForce]

For water temp just put the sender in a pot of water with a cooking thermometer and hook up the gauge. In this case it can be more about the sender than the gauge.

Rob

[Racer57]

Thanks for the suggestions.