Dad's test drive...

Worked on Dad's CJ5 today for awhile. I troubleshot the back of the gauge cluster. Everything checks out. Plus, there is a new temp sending unit, as well as a new sending unit in the tank. Both of them test good at the gauge. The gauges have all the correct ohm readings on each post, post to post, ground to post, etc.

http://home.roadrunner.com/~john.strenk/Gauge%20web%20page/basic_troubleshooting_for_cj_gau.htm

Still, neither gauge will work. I'm about to pull my hair out...

After that, Dad took it for a test drive (first time he had driven it). He ended up making a wrong turn (so he says) and was gone almost 45min. I was worried he was going to run out of gas. Finally he pulled into the house. I tapped on the fuel tank and I don't think there was a pint of fuel left in there...

But, overall, he is happy with it.

 

Very pretty rig. Dad should be proud to drive that...

 

I forget which gauge has the voltage regulator built in to it . I am thinking fuel , but that jeep is newer than mine

 

Yup, its the fuel gauge. I tested it, and the ohms are correct. Correct voltage at the terminals. The only thing I question is the 5v shown on terminal A. Some sources say that you should have 5v there, others say varying voltage with 12v being normal reading on a Fluke multimeter. I have 12v on A. I'm thinking the regulator may be bad. Really stinks, this is a newer VDO gauge cluster..

 

Can't go by voltage as different VOM's will show different voltage. Use a test light and if the light blinks ON and OFF then the regulator in the fuel gauge is doing what it's supposed to do. The on/off cycle will change depending on the amount of resistance. The sensitivity of the fuel needle part is what determines how far the needle moves. I found that my test light will move the gauge reading to about 1/4 tank.

 

I hooked a test light up to the A terminal. It flashes as it is supposed to. I hooked it up to the S terminal, and it still flashes, but dimmer as it should.

 

The very best way to kill a perfect working fuel gauge is to put it in a boat or an old Jeep.R)

I've learned to live with it. Surprisingly I have only run the Jeep out once.