Sam Buchanan

Measure the battery voltage with the engine off and if you see around 6.5v the battery is holding a good charge.

I'll say this again......a cheap multimeter (I use the Habba Fright meter all the time) can show flaky voltage readings due to ignition noise on our charging systems. I've seen it and the charging system in my car (alternator) is rock solid. The noise is sufficient to make the little LED I use for the turn signal indicator flicker all the time. I pulled up to my friend's hangar when he had his aircraft radio turned on and you wouldn't believe the racket my P15 was transmitting to his poor radio (non-resistor plugs and solid copper wires). Drive your car. If the battery stays charged the alternator is doing what it is supposed to be doing.

If you are using a digital multimeter you may get jerky readings. Sometimes the digital meter and alternator voltage regulator don't get along very well. If you have an analog meter it may give a steady reading. The lights may be getting brighter with a disconnected battery because the alternator is trying to charge a very dead battery....... The battery serves as a sump to dampen voltage surges...I wouldn't mess around with a disconnected battery with the solid-state regulator in the alternator. The needle is showing more current with lights on because.......the lights are drawing more current........that is what an ammeter does.....

Keep that welder humming...or sizzlin'...or sparking....or whatever...... ?

This is referred to as "thread creep"........this forum is renowned for our ability to drive a thread off the rails. ?

After painting myself into this corner I cut a slot in the alternator (generator) bracket so it could be slipped over the bolt instead of having to remove the bolt. The bracket is under compression so cut the slot so tightening the belt will push the bracket against the bolt.

The one-wire alternator I have starts charging immediately after start. I agree that it is a reliable solution to keeping the battery fully charged in our old cars under all conditions. A hot battery and the proper cables solves a lot of starting issues! ?

Excellent! The only reason for keeping a generator/regulator is for originality. Operationally, the alternator is superior in every way.

In far less time that it would take to figure our how to redo an alternator, this reliable vendor can have an alternator that is ready to bolt to your car at your door in 3-4 days: https://www.ebay.com/str/HowardEnt?_trksid=p2047675.l2563 I have had flawless service from the alternator I purchased from Howard. Notice their price includes shipping which is an extra $40 with some vendors. https://www.ebay.com/itm/Tractor-car-6-volt-60-amp-1-wire-alternator-Positive-Ground-w-Bracket-pulley/333591006902?hash=item4dab92ceb6:g:Y~QAAMXQobdQ7d68

Not every old Plymouth..... ?

Why not just ditch the mechanical pump and run electric all the time? Having dual systems just complicates things. Most pumps can be wired for either ground system. Here is the full-time Carter pump I installed on my P-15, it is located just forward of the rear axle:

Add an extension to the overflow tube so it will dump on the ground instead of the frame. Or just don’t overfill the radiator..... ?

That car was owned by a bubba-sized driver at some time...... ?

Once you get tired of messing around with the antique generator and regulator there is a simple and final solution. ? https://www.ebay.com/str/HowardEnt?_trksid=p2047675.l2563

Good catch, now you know what needs to be done. Also looks like the head gasket allowed blow-through between cylinders one and two. Freshen up the valves, surface the head, install the new head gasket and hopefully your engine will be good for a long time.

The education curve has been steep, only been working with them for a couple days. I'm coming in behind a mechanic who installed a rebuild kit but was sloppy with reassembly. They're behaving pretty nicely but don't return to idle quite as quickly as I like. Engine has been de-smogged...not sure how happy these carbs will be without all the plumbing.

Yep, dealing with that right now with the newly acquired TR6 with CD 175 Strombergs.

Shouldn't timing advance as rpm is increased?

The tank on my '48 P15 is unvented and relies on the cap for venting.....I thought all Mopars of this vintage were the same. If unable to find a vented cap you can drill a very small hole in the filler neck under the cap. Here is one I drilled when I was initially troubleshooting fuel delivery problems, it makes a good backup in case the tiny vents in the cap plug up:

The aftermarket sender in my new tank leaked fuel around the terminals which were loose. I also sealed the pulled rivets holding the sender together. No leaks since.

6v fuel pressure gauges might be kinda rare.......

Sometimes they just don't seal reliably (weak spring...worn seat?) and pressure/suction if present may be reduced or intermittent.

I replaced all the brake and fuel hard lines in my P15 using already-flared lengths of line from the local auto parts stores. The lines are available in many different lengths, just use a coupler between lines to get the combination of lengths you need.

The check valves can go bad.

My guess would be that in the process of swapping ammeter wires you removed corrosion on the terminals that had been causing low voltage to the entire system.