guage testing on1952 3a

JAYC1945 · Post by **JAYC1945** » Sat Feb 18, 2012 12:14 pm

does anyone know how to check the fuel,amp,guages while they are out of the vehicle? and/or the fuel sending unit. any help would be great! THANKS!

Post by **wesk** » Sat Feb 18, 2012 1:45 pm

The CJ3A gauges are completely different from the M38 and M38A1 24 volt gauges. Use the information on these pages to help:
http://www.vernco.com/Sparks/id697.htm
http://webspace.webring.com/people/dg/g ... auges.html

As a rule these electrical gauges that use senders have two circuits thru the gauge. The one to the sender and the one to the gauge's case ground. Using an ohm meter you should have continuity between the power in to the gauge and the gauges metal body and continuity from the same power in thru the power out terminal. Then check fro continuity from the power out terminal wire to the sender. Then check the sender with the ohmeter looking for a variable resistance that changes smoothly as you move the sender arm up and down for the fuel gauge. The oil pressure was a mechanical gauge on the 3A and the water temp was a integral capillary operated gauge / sensor combo. The amp meter was a simple direct reading gauge that sensed all current flowing thru it. All loads were connected directly to the back of the gauge.