Now, to my fuel gauge and temperature gauge. I did not notice this problem with the temperature gauge since I was only driving the car from the street and up in the driveway. So it was not getting warm.
But, the fuel gauge was all over the place, it was 1/4 full, half full and 3/4 full depending on the mood of the car it seemed. I had no indication what was wrong with it, I just noticed that it did not show the same amount of fuel from time to time when I started the car.
Until it one day was dead. No fuel at all, and that is when I discovered the temperature gauge was not working either. It was one of the days I was having the engine run for quite a bit to adjust the carburetor.
I took off the instrument panel, and took out the fuel gauge. Never opened one before. I went online and learned a whole lot there, about the built in voltage regulator and how it worked.
I ordered small new rivets for the gauge face, and taken apart I could see that the wire from the "I" screw to the regulator bi-metal was burned off and touching the housing. So, the instrument did not get any 5 volt at all. The wire to ground was fine.
And because of this, the temperature gauge did not get any power either. I was very lucky the wire to the gauge was the one that got shortened. This way both the fuel gauge and the temp gauge just lost the power entirely, and it did not end up being a case where they got too much voltage.
Unfortunately I did not take a picture of the fuel gauge when modified.
It is possible to get a new wire and re wire the old gauge, I have figured out what kind of wire it is. But, it will take time, and is a lot of hassle. Now, other cars in the Dodge line had a separate voltage regulator and not one built in to the fuel gauge. But, they were quite expensive and the way people had solved the problem rewiring things and messing up I did not feel too good about. So, I made my own solution.
However, this was a more complicated matter than it really had to be, but I did not know that at this point. So, I made a solid state solution that I put inside the fuel gauge sort of to keep the rest of the instrument panel original. I was advised against it, that it was not possible to make it work. Still, at
Vintage Chrysler electrical repairs and updates (part 2) I found some info that made me think it was doable to put what i needed into the fuel gauge and keep it looking original from outside.
Due to some health issues I have I came to realize that I am not a very good solder anymore, when I really try to keep my hands still they start shaking. It was not like that before, so it ended up being a horrible challenge soldering all the small components inside the fuel gauge. I now realize that is a part of my profession and former life I might have to say good bye to.
Anyway, the result was fine, I got 5 volts on the A screw on the fuel gauge which was what I was after. The fuel gauge worked, and the temp gauge too. Until the next day, and all was dead again. I thought to myself, did the guys who advised against it get the last word in this. I took the instrument panel out, and the fuel gauge, and it was no doubt, the 7805 was dead, even if I had soldered in a 1 amp fuse there and the 7805 can handle more than 1 amp. I did not want to bother too much with it, so I used a separate 5 volt DC - DC regulator I had, which is protected from all kind of things. Took out everything from the fuel gauge that I had put in, except the 1 amp fuse.
I cut the wire that goes to the "I" post on the fuel gauge, and wired in some longer pieces that goes to the new 5 volt regulator, and out from there it goes to the "I" terminal on the fuel gauge. So the wire is just cut, and the end with 12 volt goes to the IN on the regulator, and the end that goes to the "I" on the regulator is connected on the regulator 5 volt out terminal. And then the regulator has two ground wires that I stuck into an eye which I connected under the nut that holds the parking brake handle. This way I did not have to do any modifications to the wiring on the back of the instrument panel, except I removed the capacitor there. Put it in a Sandwich bag in case I need it later.
The new regulator is adjustable, so I adjusted it to 2-3 volts, and turned on the ignition switch. I measured the voltage, but the fuel gauge did not show anything. I started the engine, and ran it until the engine was warm, and then it showed a very little reading. So, I adjusted up the voltage to 4 volts and now he fuel gauge started to move a little. Up more, to 5 volts and I have 1/4 tank of fuel, and the temp gauge shows more or less what I consider correct temperature. Drove the car back in the street and went in. Too hot for me outside to continue working.
Next day comes, no fuel, no temperature. What on earth is going on I thought to myself.
Well, I am a big fellow so I struggle getting under the dash, but well, I ended up under the dash anyway, then hard to get out. LOL. But, being there made me see what the problem was. And had been all along.
When the instrument panel is out, you can see two metal tabs that holds the entire harness under the dash. Well, someone has been in there messing, and had pulled them down. So, the right tab is located just where the A screw on the fuel gauge is, and was making an excellent connection to ground. And ruined the gauge in the first place, and ruined the 7805, and made the 5 volt DC-DC regulator go down too.
The tab is painted, but there are some scratches so when I drove the car out in the street, it obviously vibrated a little and made the connection. Which was not excellent at all, for the gauges.
I took the instrument panel out, and lessened the burden on the tabs and got them pushed up and out of the way.
I have also got back all the lights in the instrument panel, cleaned and removed all the oxide on the copper, and lubricated it with CRC 2-26.
So, now it works wonders, and I have not had any more issues with anything in there. The last picture here shows the instrument panel after I removed the capacitor that was connected to the fuel gauge.
However, I have the speaker and radio out, and consider the speaker junk, the paper cone is toast and only a little part of it is left. I have gotten a new one, but that will come in a separate post.
Bill