Convert 1950 Chrysler to 12 volt negative earth

Does anyone have advice on converting the 6 volt positive earth system on a 1950 Chrysler Windsor to 12 volt negative earth?

I was at an auto repair facility (Mr Tire) having steel valve stems installed when, on turning the starter key nothing happened. I had the car trucked home and had a mechanic look at it. his initial diagnosis was a faulty starter solenoid, so I had that rebuilt. The car started but with a lot of noise from the solenoid. Out came the starter motor again.

Next diagnosis was a faulty battery, so a new one was installed. On the bench using the new 6 volt battery the starter engaged as it should. When installed in the car nothing happened when trying to start. Could it be the ignition/starter switch?

Any suggestions would be much appreciated.

This question comes up every month or so.

Short answer, don't do it. The 6V system works fine. Your car is difficult to convert to 12V + ground because it has so many more electrical components than typical cars of the era, especially the transmission control system.

I have converted old cars to 12V but don't know anyone who has successfully converted a Fluid Drive Chrysler product, although we do get plaintive questions from people who tried and failed.

Suggest you start by finding a better mechanic. Who rebuilt the starter? There are auto electric rebuilders in every town that can do the job, suggest you take the car to them or, just the starter.

Parts store rebuilds are junk although I doubt they even have one for your car.

Thanks Rusty; that was my opinion also. I had the same vehicle in South Africa (my first car, right hand drive) and never had a problem. When I bought this car in May it was equipped with an 8 volt battery, I don't know why. As I mentioned, I installed a 6 volt and it (the starter) clicked in when tested on the bench. I may have to find a new mechanic, but mine makes house calls, so it will not be easy.

Thanks again.

Don

I don't know where you live but here in Cobourg Canada (Population 16000) there are 2 good auto electric rebuilders. I could take that starter to either of them and have it back in 3 days, looking like new and working perfectly, for less than the cost of a cheap parts store rebuilt. And the quality would be much better.

6V cars are picky about having good grounds, starter cables of the correct size, and clean tight connections. More than half the starter troubles and electrical troubles we get asked about here, can be fixed for a small expenditure of time and money, simply cleaning and tightening connections, repairing frayed, broken and corroded wiring and replacing undersize battery cables.

if the car was 8 volt when you bought it then the regulator was tweaked to charge the 8 volt battery. replace the battery with a 6 volt, replace the regulator with a 6 volt one, and after checking the items rusty mentioned all should be well. of course, the starter and solenoid should have been properly rebuilt. I owned a 51 Chrysler that came 8 volt. I retuned it to 6 volt and it always started properly. the 8 volt is just to make the starter turn faster and usually mask other hard starting issues. capt den

if the car was 8 volt when you bought it then the regulator was tweaked to charge the 8 volt battery. replace the battery with a 6 volt, replace the regulator with a 6 volt one, and after checking the items rusty mentioned all should be well. of course, the starter and solenoid should have been properly rebuilt. I owned a 51 Chrysler that came 8 volt. I retuned it to 6 volt and it always started properly. the 8 volt is just to make the starter turn faster and usually mask other hard starting issues. capt den

Thank you capt den: I have ordered a 6 volt regulator. Today I connected a remote starter across the solenoid terminals and the motor cranked up without a hiccup. When I tried to start with the ignition switch it worked for a few times then simply a click from the solenoid. I suspect that the wiring is faulty as the starter switch seems to work in that it attempts to activate the solenoid.

Many thanks Rusty & Capt.

You don't need a new regulator, the old one is adjustable. Instructions in your repair manual or any good general repair manual of the time.

I think you are right about the wiring.

There is nothing wrong with an 8 volt battery although it is not necessary if everything is up to spec. If the battery is good, I would keep it and check that the regulator is properly adjusted to charge it, about 9.5 volts.

Now that I think of it, it is probable that someone put an 8 volt battery in to cure a bad starter and never adjusted the regulator.

Don't take Rusty's sage advice lightly, especially when it comes to ground connections. MAKE SURE ALL GROUND CONNECTIONS ARE GOOD, CLEAN AND TIGHT, WITH PROPER SIZE CONDUCTORS!