420-C S/N#100676

[allenjohn]

I would like to know is my crawler a ( NEGATIVE GROUND) OR ( POSITIVE GROUND ) the coil, ignition (NEGATIVE WIRE) Go,s to distributor housing. and the coil, ignition ( POSITIVE WIRE ) Go,s to IGN. switch can some one help. please advise with a explanation so i can understand why ??? Thanks !

[420CrawlerHoller]

I have a 420 crawler 1957 SN is 100k+ and it is positive ground.

[Lavoy]

Your crawler left the factory positive ground, it is possible that someone changed it in the past, but it is supposed to be positive ground.
Lavoy

[Jim B]

As 420CrawlerHoller's and Lavoy's posts, yours would be positive ground unless someone has converted it. They were all positive ground. We need some more info to confirm it has not been changed over the years. 1. Does it still have a 6 volt battery? 2. Does the cable connected to the battery positive post go to the machine frame (ground) and the negative post cable go to the starter switch (hot)? 3. If the answers to 1 and 2 are yes, then it is still the 6 volt positive ground system, as original. The wire from the ignition switch should go to the (-) terminal on the coil. The wire to the distributor should be connected to the coil's (+) terminal. 4. Does you machine still have the generator (is there a Delco Remy number on the tag on the generator) or has it been converted to an alternator? If the answers to 1 and 2 are no, you need to tell what the battery is and where the cables from its posts connect to the machine, similar to the way I described the 6 volt cable connections.

A coil will usually work with the wires connected to either terminal. They usually perform better if the distributor is connected to the terminal that matches the machine ground, because the points making and breaking the circuit connection to ground is what makes the coil produce the voltage for spark.

HTH

Jim

[Allen John]

I had check there is a 8 volt battery I think for extra juice on start- up .so they switch the coil wires I should change the coil + & - wires to the same way the electric diagram is on page #127 IN S/M #2019.

[Jim B]

You answered my question one - you have an 8 volt battery, not a 6 or 12 volt battery. You did not answer question 2, "Does the cable connected to the battery positive post go to the machine frame (ground) and the negative post cable go to the starter switch (hot)?" That will make the difference on which way the wires on the coil should be.

[Lavoy]

8 volt batteries on the whole don't work very well. They are lower CCA to start with, and your generator will only charge it to 6 volts which just adds to the problem.
Lavoy

[shinnery]

Sixty some years ago I ran an 8 volt battery in an old Dodge I was trying to drive. Back then I found a generator shop that was able to adjust my voltage regulator so that I could keep the battery charged, It was rough on headlites as only the bulbs marked 6-8v would last more than a few minutes. I needed the 8 volts to get that Dodge spinning fast enough to get enough compression to start. Or pour oil in the carb. LOL Probably '57. I graduated from HS in '59 (and had moved up to a '52 Ply.) and went in the Navy.

[Allen John]

I talk with my son who disconnected the cable,s from the battery back in July. he don't remember how it was hook- up. and there are no notes. looking at the battery tray on the right the red cable go's to ground. and the black long cable on the left go,s to the starter switch. Lavoy & Jim.B. Again I really thank you all for the information and the help. { note: this do's not mean that it was hook -up the way it calls for. ??? } where do I go from here without shorting out wire's Thanks!

[Lavoy]

It won't short wires, just poorer spark, and may not charge if not polarized. If you don't already have it, get a service manual, it will have the wiring diagram to put it back correctly.
Lavoy

[Allen John]

I do have a service manual #SM-2019

[Jim B]

Cable colors are not a safe indicator of positive and negative. Check the battery posts. One of my neighbors went on the red cable is positive theory, which made his battery hooked up backwards, and smoked an alternator. Things will work either way with a generator, but as Lavoy posted the generator has to be polarized to match the battery. Wire it like the diagram in your manual. Does it charge now?

[Lavoy]

Then I would trace the wires and make sure they are all in the correct place.
Lavoy