1970 land cruiser charging issue

[LIL EVO]

My fj40 is on plow duty, but I'm having some type of charging issue.

With the truck running, at the battery reads about 12.3 - 12.5 V.

I've replaced:
Alternator
Battery
Tried a second voltage regulator

I have a ground cable to the block, a ground cable to the body, and a power wire to the starter. Tried new thick cables.

The ammeter reads just below 0 with the truck running, although I don't even know if it works.

Any ideas? Any on the truck tests I can check?

There isn't much to the system so I'm not really sure where the problem might be.

Someone mentioned a bad starter may cause this issue

[Moparjim]

Ammeter itself could be your problem.

Unlike a voltmeter, the ammeter is in SERIES as it measures current flow and direction THROUGH it. It is usually wired so indeed all the power from the alternator goes through it, so it can measure the charging or discharging.

On old Mopars, it is common for the ammeter to fail OPEN so nothing goes through it...

I would think it should not read ZERO, no matter what is happening - if you turn lights on and off for example with say car off even does it move? If it always reads zero I bet thats your issue.

[Reverend Cooper]

needs the ampmeter replaced if it reads zero or there is a wiring issue,does it run the battery downa nd not charge the battery,or are you guessing?

[LIL EVO]

Ammeter reads less than zero depending on how many accessories are running.

With lights and heaters running output is around 11.8 v. With nothing its 12.3 v.

It holds solid there no matter how much I use it.

Someone suggested replacing the mechanical regulator with a solid state so I will try that.

[-stew-]

Are the alternator and voltage regulator properly grounded?

[LIL EVO]

Yes.

Readings are the same measured at alt or batt