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My 39 120 was converted (partialy) to 12 volts before I bought it. The alternator works well, but I don't like using the step down capacitors for the heaters and gauges. And I would like to keep it as stock as possible.

I have two nice generators to pick from and will probably go that route. I think I need to buy a new 6 volt regulator, coil and bulbs. Is there anything else I need to change?

The starter I had rewound several years ago as a 12 volt - will I need to have it changed back to 5 volt?

thanks for the advice.

If it has electric OD, you may need to look and see if anything was changed --relay, solenoid-- also maybe horn relay or horns. If a radio, what was done to make that run on 12v? Starter may turn on 6 but probably no torque so I imagine it will need to go back and solenoid as well.

If any of the wires were changed, I would check their gauge and make sure they are thick enough.

thanks for the input - I'm putting in a brand new wiring set so that should take care of the wires. I see lots of time at Napa in my future.

When I converted my 53 Clipper from 12 back to 6 volt I put in a 6 volt thermal flasher. Not sure what the situation is on the 39 120 on turn signals, but if it applies, you may need to replace the thermal flasher. NAPA has it. Some people just leave the 6 volt starter in there even with a 12 volt conversion, so you might want to check the starter to see if it is a 6 volt before you run out and get one. Mine still had a 6 volt starter. If they did it right, they should have put in a 12 volt generator (or alternator). If they did not do it right, they may have just left the 6 volt generator in there. Mine had a 6 volt generator as well. My car would run on 12 volts with both 6 volt starter and generator but both would have worn out a lot earlier. Go to an auto electric shop and let them see what you have before you buy a lot of stuff. Could save $$.
Ken

Thanks, Napa is my favorite store, even if sometimes I have to explain who manufactured Packard! They have two 6 volt coils - a Echlin IC7 for $46 and and MPE IC7SB for $19. The guy on the counter told me the Echlin is the premium brand and the MPE is the "bargin basement" type. Any recommendations? I don't mind spending the extra money, but it would be nice to use the less expensive model if the performance wouldn't suffer.

If you're talking ignition coils, keep the 12v ones...doesn't really matter. Make sure the polarity is correct or your spark won't be optimal...but it will likely still run pretty good. I run the 12v flamethrower coil on my 6v pos ground setup, great spark.

I don't recall where i got this information, but i spent a few days researching coils when i did my pertronix setup on the Packard and on my 12v 4 cyl boat. I believe getting the correct ohms rating for the number of cylinders was the most important factor.

However, i do recall them saying don't use a 6v coil in a 12v setup.

Run the $19 coil and BUY A SPARE to carry in the car! Test it out for yourself. Save $6 in the process. Pay $46 for the 'good' coil and no spare then u're stuck on the side of the road unless u spend for a spare.

I've ran 6v coil off of 12v (for short periods) but never 12v off of 6v so i don't know. Try it!!!

According to a reliable electrician i know he explains it this way:

If a 6v coil on a 6v system is good for 60K miles then it ought to last at least 40K miles when used on 12v (use the usual ballast resistor).

THis 6v/12v coil issue came up a few months ago and that was his answer. I'll have to ask him about the converse of using 12v coil on 6v system to see what his opinion is on that.

Chances are the $19 coil is just a 12v coil (maybe somekind of a 12v cull coil due to production control problems) repackaged as a 6 volt coil anyway.