lgad

This is going to sound elementry, please keep in mind I'm uneducated when it comes to automotive wiring....On my 1950 Chrysler New Yorker (Straight 8), I want to know if it's positive ground system. How do I find out? Is it something I can change/reverse if it is? The battery I have is Negative ground (I guess they sell both, having both kinds of systems!DUH! I know I sound like a kid asking this stuff, please forgive). I don't want to fry my 6volt 61 year old wiring harness, but I'm having trouble getting it to do anything. I can hear the starter relay making a clicking sound when I turn the key to the start position. I'm testing the wires and connections with a multi-tester, not sure about what I'm reading, there again I'm not sure of what I'm doing.

6 years ago I had the car running. After parking it, I got rid of the battery without knowing if it was pos. ground or neg. ground. My Pop has done some checking and he's thinking it's pos ground, but I afraid to hook it up backwards (*in my mind I can see the puff of smoke and flash of light/sparks and the smell of burnt wires/electrical fire!)

Is this something I should throw in the towel on and just rewire (painless wiring harness?), and convert to 12volt?

Any info/help/advice will be greatly appreciated.
Thanks,

Larry

ps Maybe I can get a photo today after work, and get it posted on this thread. Thanks again!

440roadrunner

According to my old Motor's Manual, all old Chrysler 6V is POSITIVE ground.

Here's the deal on positive/ negative ground.

There are some things that "matter" and some that "don't"

(Back then) Motors, like your heater and starter, were "wound" field, and so "don't care." Either polarity will run them the correct direction. Modern "mini" starters DO care because they have permanent magnet fields, and will reverse with polarity

Alternators/ generators.

Generators have to be "flashed", or "flash the field" or "polarized." This is a procedure, done at installation, where you momentarily short a couple of connections at the generator/ regulator to cause a weak magnetic field in the iron core of the generator. Once formed, this field "stays" in the core and "boosts" the generator into the correct output polarity. THE PROCEDURE IS DIFFERENT FOR CERTAIN GENERATORS so don't go around "flashing stuff."

The regulator. OEM regulators were routinely made for ONLY ONE ground polarity. This is because of the metals used in the regulator contacts. A "one polarity" regulator that is converted to the opposite polarity will eventually burn out it's contacts.

Many aftermarket replacement regulators were made with better contacts and were sold as "either" polarity. This was to reduce stock inventories, and was a good idea.

Alternators are difficult to reverse. You have to replace all 6 rectifier diodes with reversed polarity, and if you have one new enough to have a solid-state regulator, that will have to be changed. There are (or were) a few large trucks that were positive ground. I never knew why

Your original radio "may" care, it depends on the circuit

You would have to reverse the connections on the ammeter

Most other gauges, temp, oil, fuel, "don't care."

You'll have to reverse the ignition coil connections, or the spark will be reverse polarity.

Some more comments on generator systems:

I don't want to sound as if I'm "being scary," but there are pitfalls with generators.

FIRST most generator systems are a little "light" in today's world. This means that you cannot hang a bunch of accessories on the car and expect the generator to "live."

SECOND if you have trouble with the regulator, it is imperitive that you get the GENERATOR number and a parts guy who knows what he's doing, and match the new regulator TO THE generator. This is because the regulator has a current limiting relay (one of three) which protects the generator.

(Conventional regulators have three relays, 1. voltage regulator, just like on the up to 69 Mopar alternators. 2 current limit, mentioned earlier. 3 "Cutout." The cutout is VERY important. The cutout disconnects the generator from the battery when it's not charging. If the cutout fails, the generator will attempt to "motor".

If you ever stop the car and the ammeter is mysteriously drawing current, unhook the battery!!

Once, on my old '57 Chivvy, I threw a fan belt just as I was getting home. I heard it "go" and drove on in. When I shut off the car, the generator was motoring over!!! This is because it had been charging, and had thrown the belt, and was still spinning. This "locked" the cutout relay in place because normally, the generator would have stopped rotating when the engine shut down.

If you decide to convert this car to 12V it is not all that much trouble.

Replace all bulbs with 12V

Decide what to do with the radio Some can be converted, some are not worth it, or replace with modern gear "hidaway" in the glove box, etc. There are some radios that someone is putting modern gear inside the old case (expensive)

Get "volt a drops" for such things as the wiper motor and heater blower

For gauges get the "Runtz" regulators (Google 'em)

Buy a 12V coil and resistor

Either get a 12V generator or alternator

You can use the 6V starter, and probably the solenoid

Reverse the ammeter connections.

rdrunner1974

It makes no difference WHAT battery--6 volt. Just be certain that the positive cable is on the ground connection.

lgad

thanks for so much info, wow I like this forum more and more each day! I wish I had more photos from this weekends Braselton Bash Carshow/Wing cook off! IT WAS AWESOME! There was also the end of the Bandit Run (All the Smokey and the Bandit you can handle!), wing cook off, and no telling how many cars were there! Mopar's were well represented, my neighbor let me drive his 70 Nova and his 68 Vette! I had a blast got my seat foam for the NY! ready for more to get done this week, thanks again for the answers to my questions~lgad

lgad

UPDATE~ I got the starter off the car! My Pop got it disassembled, cleaned, and reassembled. We put it back on the car, and Voila! we got the engine to turn over! The car is NOT positive ground, couldn't believe it, we tried it both ways, and it is negative ground. So if any of you out there have problems with positive ground, try it the other way, I guess like 440roadrunner was saying it can be either way, just depends on how it's flashed, or set up from the factory (or by mechanic). Should be able to get a few new pics on here soon, and hope to get the old gal a little bit closer to being back on the road!~lgad

78D200

Thats awesome! I'm glad that you were able to figure it out.

lgad

Yeah, me too, I was worried at first, but after trying it and getting it to run, I don't know why I was so scared!LOL! I'm a newbie! But that's something else to add to the list of things I know now!