The Stovebolt Site Forums The Shop Area The Electrical Bay Starter issues and 12v conversion

My new to me 1940 216 1.5 ton runs amazingly... if I can get it started!

I have a used 6v battery and a brand new 6v battery that the previous owner included with the sale. Even when I jump them together I get slow cranking and 50/50 chance of it starting. It doesn’t seem to matter how much I charge the 6v batteries they still crank super slow.

Then I tried jumping to a 12v battery and WOW! It started in half a revolution!!! I mean it started quickly and with a purpose! It seems that doubling the cranking speed is like starting magic!!

So Instead of replacing the old 6v starter I’m considering keeping it and just converting the whole system to 12v negative ground.

Advice?

A 12V conversion is a cop-out by people who are unwilling to go to the effort needed to make 6 volts work. There is a huge amount of information archived here on the subject, and I'll suggest you read as much of it as possible before making a decision one way or another. I'm dealing with a crippled right hand after surgery for an infection, or I'd be glad to waste a few billion more electrons than the ones I've already dedicated to the subject. Long story short- - - - -6 volt cranking/charging systems are perfectly adequate to get the job done, but they DO NOT respond to a piecemeal approach. Every connection and component MUST be exactly right.
Jerry

6v has been working OK for me since 1969.

Ditto on the 6 volt working as designed. I dont have the extensive time under my belt as tclederman has, but unless you have a legit reason to change to 12 v, then why? In my 51 Chevy 2dr sdn, I used the factory 6 volt system for 3 years or longer. Worked well, headlights were suffice, along with everything else powered by it. Not to mention, I could see without blinding all who where coming at me. Truth of the matter is I would still be using the 6 volt system, except I put a 261 in place of the 216 when the clutch failed. The 261 was waiting patiently for a reason to be put to work. I switch to 12 v at that time because that's what powered the 261. I also kept it a generator setup as it seemed right at home for it. Anyhow, my point is that if it aint broke, dont fix it. And if it is broke, fix it as it was designed. 6 volt batteries are pretty available to boot. 6 volt starters love 12 volts.....I guess you figured that out already.

I understand 6V negative ground, I have an old ford tractor that has the same system. It started hard until I installed electronic ignition. Now it starts like a champ. Every vehicle so different and hs been treated differently during its life.

I was with the previous owner when he went to Napa and bought the new battery.... so I know it’s new. Jumping with 6v it still cranked slow. Jumped with 12v and it turned over much faster and started almost instantly.

If you're trying to use jumper cables with the new battery, you're wasting your time. Bolt the new battery in, with BIG cables hot and ground, and your slow crank problems will probably go away. Otherwise you're wasting everybody's time, including your own.
Jerry

First thing I would check would be the cable connections at the battery. They should be shiny clean on the in side of the clamps as well as on the battery posts. Also check the cables themselves for corrosion. The green goo that develops under the insulation is terrible at conducting electricity.