OK guys, here's the scoop.
In one of my recent post I have this stupid reocurring fuel gauge problem. My truck was converted over to 12 and the fuel guage burnt up.
I got this gauge cluster out of a 1959-60 school bus, the fuel gauge works. Now my sending unit in my tank was rusted so bad that the float rod was almost rusted in two. I performed a bench test using a 90 ohm sending unit (something I had lying around) having 90 ohms stamped on the unit itself I also checked it with my meter just to make sure I was in sync with my so-called electronics knowledged and it was correct.
Now, this is where I am confussed. I do not know if I need to order a new 30 ohm sending unit or a 90 ohm sending unit. The reason being as I moved the float up or down I recorded the different positions and what the Ohm reading was, this way I could about guess where empty, full and so on was. A little more than half way was at 30 ohms and then the gauge reading was 1/2 full and then a slight more movemant of the float it reached WAY PAST full. By now, I am talking to myself should be a 30 ohm sending unit or a 90 ohm. Now, I could have been using a flawed unit, but it appeared to be new and never used or mounted in a tank and the readings wasn't jerky, nice and smooth. Is it possible that by 59-60 could Chevrolet have used a 90 ohm sending unit? I thinking they may have used what they had left over from the eariler era and for a bus who really cared, I don't know but it's just a thought. It looks just like the one in my 54 round and has the 4 major gauges, the only real difference was they went to an electrical temp gauge and then they used the spade type connection held on with the brass hex nuts, where mine uses the round terminal type. ANY IDEAS HERE?????
Then to top everything off when I switch on my regulated power supply over to 12 votls DC the needle viberated and slightly hummed at the empty mark, I quicky switched back to 6 volts and it seemed to be ok.
What I can't understand is why would the gauge do this on 12 volts. Like I said this came out of a bus that I know was new enough to be 12 volts from the factory and there wasn't any resistors to drop the voltage back down to 6 volts. Now I am second guessing my theory on the 12 volt gauges in the bus I didin't think that Chevrolet used this type of dash cluster past 1954, so didn't the 55 1st. series had the same dash as 2nd series, that upside down triangluar looking thing? I'm no historian on what was done and what wasn't, that's why I'm here.
All I know is that I am sick and tired and just TOTALLY fed up with this darn electrical fuel gauge problem. I am just about to the point and ready to just use a stick in the tank, say the hell with this dumb goofy gauge. Just like they did in the good ole Model T **** days.
I was all ready to order a new unit, now this. They list both in my catalog....What goes?
Any help, as always GREATLY appreciated
John Niekamp
