Ross makes a good point. Centrifugal force could easily be at work in the armature causing a short. The test he mentions is easy enough to do and well worth doing as a first step. I am not sure it will be definitive as to the cause though. The regulator, still being in the circuit, could also cause the generator output to lower if either the current section or the voltage section thinks it sensed too much and starts limiting. Would be good to check and see what the actual voltage is though in case it is going high (unlikely, but possible).

Unfortunately, taking the regulator out of the circuit and then running at speed long enough to measure anything without some safeguards could cause real damage and is best left to a proper shop.

O_D's suggestion is also good and hopefully done by the shop that rebuilt generator but unless there is a suspicious area that looks discolored or otherwise different to look at now, don't know how much will be found in a static test since it works well most of the time and only happens at speed.

The Runzt solid state type regulator many sell wouldn't hurt--although it would take one per gauge. Downside of those are expense and although the prices seem to be all over, generally $15-20 ea. Also require neg ground. Doing a conversion, expect you are headed in that direction anyway. Assuming ground not being an issue, then unless someone accidentally hooks up the battery backward thinking the car is still pos ground and they don't survive, maybe worth looking into.

The original voltage regulator is mechanical and like anything mechanical and 60 yrs old, possibly showing age. If the contacts stick, it is all over and it is find another gauge time. That can happen on any car that uses that type of regulator. Of course, the same happens if the IC on the Runtz shorts.

It would be very interesting if you could access or remove the BTV more or less intact and in same orientation. Unscrew the compensator valve assy and see if there looks to be anything wrong with the spring or poppet and are any chunks of solidified brake fluid floating around at top of actual MC part around that area that could lodge under the valve.

That would go a long way toward seeing if a theory that heat and moisture in that location is causing problems that seem mostly reported on the V8s..

Packard manual also mentions using a windshield sealer and to make sure it fills the spaces which may be the adhesive someone else mentioned going into the chrome flange. There are some clear and fairly liquid types on the market and believe it would take one of those to wick inside and fill the spaces. On a lot of the other rubber installs from various years they mention using liquid soap as a lubricant when trying to slide glass in the rubber. Might help.

Also there is a lube point some have had success with. Check out the first 3 posts herehttps://packardinfo.com/xoops/html/modules/newbb/viewtopic.php?post_id=29855#forumpost29855

You're right! I had completely forgotten that even till 64 Hawks had the mechanical oil. The only way they could use the full cluster and a Hawk loom would be add a wire in for the oil or add wires to the 57L loom for the ammeter.

I would take it somewhere with some decent diagnostic equipt and verify the output at various RPM.

Assuming no wiring was changed, the bulb is between the A or gen terminal on regulator and the B or bat terminal. Only way the light can illuminate is when the voltage differential between the normal battery voltage and generator output is enough to light the bulb. When no charging, the battery supplies a voltage which feeds to one side of the bulb and other side goes back thru generator and gets ground thru windings there. When generator starts supplying a voltage then that voltage will match the battery so each side of the bulb is at same potential and it goes out. When idling, the gen voltage is not quite as high as the battery so the light is dim or flickers when the regulator cuts in and out.

It almost sounds as if the regulator/generator is not the proper match or the regulator might need adjusting and is regulating too soon. Either due to current or voltage, it almost sounds as if the regulator is cutting off charging at 60. I guess it is also possible something is amiss with the gen rebuild--but don't think as likely as a mismatch or adjustment. The light could also light if the voltage from gen is much higher than battery but if that were the case, I would think all kinds of other bad things would be happening.

Again, one of the many anomalies we have found in various models where what is supposed to be there doesn't match what actually is for whatever reason. At any rate, they are there and if it is factory, would be an interesting find. What I would also find interesting is how it was done if there is any way you could see. Too bad the owner can't answer some questions.

The only cluster case shown or mentioned in Stude lit will not accept the two bottom gauges as is. Did they cut the openings in the Stude case or adapt the Packard and if so, how. Stude has 3 mounting locations, 1 on each side, 1 on bottom and Packard has one at each corner. Did they add some tabs to Packard or relocate some screws on the flimsy dash. Otherwise, they appear to be similar in size and shape. Without being able to compare them, can't tell if any other differences.

The wiring loom would also be interesting as they would either have to use a Hawk loom for the additional instruments or the original would have to be modified in some way. That would be a clue as to whether the factory did it.

One of those anomalies only Packard or a real expert on 57 knows. The signal seeker radio was an option. Appears to be a senior style unit with the fine vertical pattern on buttons with different knobs--Maybe Clipper but shape looks wrong so maybe Stude also.

The dash is fiberglass on 57 and it is a bit flimsy compared to 56. The difference in the cluster appears to be the back half of the mount. 57 has two tabs-one on each side which go on studs I believe was molded into the glass and 56 has 4 - one at each corner.

Attach file:

---

  (47.80 KB)

There is not a simple or single how to do it article on site here. Use the search box at upper right and search for 12v conversion. There are quite a few things to consider and some pitfalls but it can be done if you are not worried about authenticity and just want modern convenience. There are many threads on one aspect or another but just about everything is covered. You might also check out Big Kev's blog as he is doing just that on his 54. You'll have to skim thru as pieces are mixed in as he progresses.https://packardinfo.com/xoops/html/modules/newbb/viewtopic.php?topic_id=57&forum=10

One site does have a printed guide for sale but I have not read it and am sure it duplicates most of what has been discussed here.http://www.fifthaveinternetgarage.com/parts/index.html