Another Speedometer Cluster Question

My fuel & heat gauge are not working in my speedo. cluster. The guy that I bought the jeep from told me this, and he gave me a replacement cluster that he said he had bought but not installed yet. I would like to check the fuel gauge before I change everything onto the new cluster.

My question is, if I hook up fuel sender wire to the far left prong, nothing on the center prong, and the 12V power wire to the right prong, will the fuel had work if everything else is good even without hooking anything else up. He installed a new fuel tank and sender before I bought the jeep, so it shouldn't be the sender, as long as he installed the right one.

Also, I read about momentarily shorting out the fuel sender wire connector point to see if the gauge has a problem. What is the easiest way to check the gauge?

Is there a way to check the temperature gauge by doing the same thing? I know he replace the wire from the sender when he installed the painless wiring kit. However, when I looked behind the original gauges, he had a splitter on the 12V supply wire, which went to both the fuel and temp. gauge. My guess is, this ruined the temp. gauge. Would that be correct, considering the 12V was going directly to the temp. without the regulator?

 

Pretty sure this is a '75?

The factory service manual will have procedures for testing the instruments. If you don't have one, they are available as reprints from many places. Note this is the factory manual, not the cheesy Haynes or Chiltons manual. The reprint fills a 3-ring binder about 2.5" deep, and covers only the 1975 model year. Highly recommended.

There used to be a '75 manual online somewhere, but I don't have the link and have not been able to find it again. There is a '76 manual at www.oljeep.com but there were a boatload of changes from 1975 to 1976, so be aware. I am very hesitant to recommend your looking here, since so much is different from 1975 to 1976, but the instruments part should be basically the same - enough info for you to test with. The wiring diagram will be close too. Don't assume that anything is the same though - if your Jeep does not match, then you can't use that manual.