Hey everyone, I'll try to make a long story short, but have plenty of details to try to help make things clear. I have had my 67 Dart GT for about 20 years now, and have been on and off here almost as long, need to donate again to get my board sponsor status back up because I am going to need help now that I am back to working on it!

It sat for a while and had some issues with gauges not working right. During covid I got it fired up and drove to work and back a few days, and then on one trip to get carryout with the wife it died on the way home. It sat for about an hour and then started back up just fine. I drove home, and then it's sat for a couple years. Without working gauges, it was tricky to determine what factors may have led to it dying and not restarting and then starting again. (Do I have fuel? Is it overheating? alternator working? no clue!) So I took the dash out, and decided to do the whole enchilada in hopes of never having to mess with it again. I know it's not ideal to replace multiple things at once because you add more possible failure points, but it's a pain to get that dash in and out!

I had Williamsons (look for my post from June 2020, would strongly recommend against using them) replace the ammeter with a voltmeter and do some cosmetic work to the gauge face and other dash bezels, and found a father/son company that makes repop circuit boards since I had multiple broken/missing/loose pins on the original boards. I replaced the bulbs with LEDs and new holders as some of those had failed too. I finally got around to messing with it this week, trickle charged the battery and it's holding 13+ on my multimeter but no lights come on inside, doesn't turn over, headlights, wipers, etc don't work. I know the battery is good, my auxillary things like a stealth mounted bluetooth receiver/amp that are wired direct from the battery to a mini fuse block all work fine.

-I checked and power is getting through the fusible link, have replaced that previously.
-Battery cable ends were a bit beat up, replaced those and made sure the posts were clean etc.
-I get around 0.6 volts at the cigarette lighter and both sides of all fuses.
-I accidentally bump started across the relay when checking for power and the starter turned over.
-Voltmeter slowly moves to the right side of the range with key on and back to the left when the key is off.
-Ignition switch replaced a while back, plug was pulled loose while doing other work so I reconnected it solidly.

In my FSM, it describes a voltage limiter test, but the way it's formatted, it's not 100% clear to me if that is relevant to all models, or only the electroluminescent lighting in the Charger? It says to connect one end of a test light to the temp sending unit (assuming on the top of the head? tried to put the pointy end in where it was touching the top of the sending unit stud with the 90 degree plug making loose contact) and the other to ground, with the sending unit lead wire still attached. With the key on it should flash if it's operating and no go there. Does it sound like I did that right?

So possible failures:
Voltage limiter?
LEDs in backwards/ incorrect polarity?
Voltmeter?
Circuit board?
Something else? Maybe something is redundant when ammeter is removed in favor of voltmeter and has to be left out?

Thanks in advance for any input!

Hi Andy,

Sounds like maybe the voltmeter was not installed correctly in place of the ammeter, and/or perhaps it is smoked? If your old ammeter (stock wiring) had a loose terminal, or it was smoked (open circuit), this is what the car would do, if I am understanding you correctly. I would think the LEDs would just not light up if they are in backwards. I don't see how the gauge voltage limiter could cause the running problem (but could cause the gauge problems of course), but others may know more.

As far as running and then dying, I have seen this happen when you have the reluctor leads reversed on an electronic ign distributor. Works fine when cold, but when heated up it will not trigger the ign box properly, but runs fine again after it cools. Flip them the right way and no worries. This would be unrelated to the gauge/voltage issues.

Sorry I do not have time to think more, but maybe I'll have more time later. Some ideas, anyway...

Lou

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Home of Slant6-powered fun machines

Thanks for the input! No major changes to the ignition stuff for a long time and has HEI retrofit. Replacing that module may be a good troubleshooting step once I have power everywhere though!

Thinking that the dying thing may have been related to something on the fuel side.

The voltage limiter is there to limit the voltage going to the oil pressure, water temp and gas gauge to 5 volts. If the voltage limiter is still the oe unit it should be replaced as if it fails and sends 12 volts to those gauges, the gauges will be immediately fried. There are new solid state limiters available.

The voltage limiter is not the cause of your no start or light issues. I would begin trouble shooting by checking for voltage at the ignition switch terminals with the key in the crank position. You will need a FSM with the wiring diagram to do that. If you are seeing voltage there it’s a matter of following the current path,, with the key in the crank position, next place that current goes to is the dash voltmeter, the starter relay, the ignition system and so forth….

I read that the headlights are not working,, those are independent of the ignition switch,
When you had an amp meter on the car, all of the current in and out of the battery-alternator flowed through that gauge. With a volt meter, that gauge is sensing the power potential in the car’s electrical circuit so it is basically a reading off one circuit in the system. Almost no current flows through a volt meter.
What did you do with the oe wires that were leading to and from the original amp meter? A simplification is those two wires need to be joined together.

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Seems like the voltmeter is wired wrong, will hopefully have some time over holiday break to tinker with it, thanks Lou and John for the input!