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Author Topic: 12v setup for cheap?  (Read 94 times)

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Offline MikeP

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12v setup for cheap?
« on: September 21, 2019, 12:03:02 AM »
so im gonna be buying a new harness for ma jeep and its currently 6v which is fine but i want to run modern stuff like radios etc so my main questions is do i need a new starter cause id really like to keep using the foot start ability and do i need to buy the 330 dollar willys alternator kit or can i just go to the junkyard and pull a ford alternator etc and will any 12v regulator work
1950 willys cj3a

Offline Rus Curtis

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Re: 12v setup for cheap?
« Reply #1 on: September 21, 2019, 08:55:14 AM »
Mike,
I converted my '54 a long time ago.  The stock setup, i.e. push button starters and generators, was still in use when jeeps were converted over to 12V during production.  This is what I did;  I got a 12V generator/regulator and left the 6V starter in place.  No bracket or fitment issues.  No additional grinding to get aftermarket parts to fit.  I am however, looking at some kind of maintenance down the road on that 6V starter.  My biggest bonus is it "looks" stock.

You don't need a new starter but you do have to understand that the 6V starter will turn faster.  It will engage the ring gear harder and will have a shorter overall life span.  It can however be rebuilt.  It can also be replaced with a stock 12V (some have posted the 6V can be rewired - beyond my garage skill set).  Whether to use the push button or not is up to you.  The 3-way ignition switch has no momentary on, like a modern ignition, so there needs to be a spring loaded starter function, a.k.a. foot switch.  There are ways to convert to using a solenoid if you prefer. 

Reading the article on alternators on the CJ3B Page or scanning all the posts about converting will let you know that other alternators will work and which is preferable (sometimes based on availability).  You will need a different bracket to allow a decent sweep for the alternator so you can remove and install/tension the belt as well as aligning it with the other pulleys.  The vendor offered conversion kit is intended to be a "one stop shop" conversion but you will still need to alter your harness just a bit to compensate.  Pricing salvage parts and then sourcing a bracket will tell you whether you'll save overall (also what's the remaining life-span on that used alternator before it needs new parts?).  Typically you match the alternator and regulator to ensure they work together (Note:  some of these conversions describe using an alternator with an internal regulator which simplifies installation).  I've never tried to mix but I'm sure others have and can describe the pros and cons.

The biggest difference between an alternator and a generator isn't voltage. It is possible to find 6V or 12V versions of each.  I think the biggest difference is alternators put out more charge at idle.   Generators need a little rpm increase to register a charge. 

One added bonus now.  Since we are sharing bandwidth and combining DJ's and 3B's with the 3A crowd, you are effectively doubling the available expertise and knowledge base that could offer advice.  So get ready for a lot of input.
'54 CJ-3B "Green Gruntt"
Bantam T3-C

Offline MikeP

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Re: 12v setup for cheap?
« Reply #2 on: September 21, 2019, 10:21:44 AM »
1950 willys cj3a

Offline SteveKfl

Re: 12v setup for cheap?
« Reply #3 on: September 21, 2019, 02:21:31 PM »
Just a suggestion.  Save yourself some fabrication effort on the bracket by checking the "mount hole indexing".  There are at least two that I am aware of.  It looks like both examples shown seem to be at approximate 180 degrees similar to my original generator mounting holes indexing.  Mine now is a little greater than 90 degrees indexed with a fabricated lower bracket .  That kept the center of the pulley closer to the block on the upper factory bracket adjustment area using a shorter belt and just slight upper bracket alignment adjustments.  Here's an example to show the index difference.     https://www.ebay.com/itm/Remanufactured-100-Amp-ALTERNATOR-GM-Chevy-Chevrolet/192896807318?hash=item2ce98bb196:g:H2EAAOSwO2hb0Snw
« Last Edit: September 21, 2019, 03:08:56 PM by SteveKfl »
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Offline MikeP

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Re: 12v setup for cheap?
« Reply #4 on: September 21, 2019, 03:48:49 PM »
this my current setup
1950 willys cj3a

Offline SteveKfl

Re: 12v setup for cheap?
« Reply #5 on: September 21, 2019, 07:26:25 PM »
This is my fabricated lower bracket and "adjusted" upper bracket... I hope the attachment works.
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Offline Mark W.

Re: 12v setup for cheap?
« Reply #6 on: September 22, 2019, 04:25:11 PM »
Keep in mind no alternator will come with the proper sized pulley for the wider belts. Speedway motors sells pulleys designed for alternators mounted on Ford flat head that are cheap and work well.
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