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Converted from 6 Volt to 8 Volt

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MikeG1949 View Drop Down
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    Posted: 23 May 2022 at 7:58pm
Many years ago, after our frame off restoration, we converted our '48 CJ2-a to an 8 volt system because it had trouble starting. Then we had the voltage regulator adjusted by an old time mechanic, who is no longer in business .  It's not driven much and I keep a tickle charger on it 24/7 and so it starts and runs fine.  However, the dash amp meter never shows any charging.  And if I turn on the headlights, even when the engine is running, it shows a significant discharge.  I put a multimeter on it at the generator and it shows an output of from 2-7 volts and runs 6.5-7.2 most of the time.  

We're thinking the output should be at least 10-12 volts for an 8-volt system.  It's been suggested that I replace the brushes and clean the slip rings to start with.  I checked at NAPA today and they said they don't show a generator in their books so they can't order a new one.

Also, the manual reads, "For replacement, voltage regulator and generator must be matched for voltage and capacity, polarity, and common source of manufacture. Otherwise, either a loss of ampere capacity or a burned out generator will result."

Anyone have any suggestions before I set off on this project?
Mike G 1948 S/N 197198
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Bruce W View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Bruce W Quote  Post ReplyReply Direct Link To This Post Posted: 23 May 2022 at 8:59pm
  My suggestion: Return it to 6 volts and repair it correctly. Tear off the band-aid and throw it away. It’s obvious that this 8-volt conversion didn’t work for you. Whatever prevented the 6-volt system from working is probably the same thing that’s not letting it work on 8 volts either. Fix it right and it will work. 
  And whoever suggested that you clean the slip rings in the generator evidently doesn’t know his axle from his polar ground, because a generator doesn’t have any slip rings. 
BW 


Edited by Bruce W - 23 May 2022 at 9:01pm
It is NOT a Jeep Willys! It is a Willys jeep.

Happy Trails! Good-bye, Good Luck, and May the Good Lord Take a Likin' to You!

We Have Miles to Jeep, Before We Sleep.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote cpt logger Quote  Post ReplyReply Direct Link To This Post Posted: 24 May 2022 at 3:35am
While I am with generally with Bruce on this issue, an eight volt system can work well.

First I agree that since the eight volt system is not working properly, the time and $$ to make it work will most likely be the same as to switch it back to six volts. However, in your case I suspect that just swapping in a six volt battery & good cables will fix this issue. Your charging voltages are In spec for a six volt system. An eight volt system needs closer to 9.6 volts. That is what I ran in my eight volt VW Baja for a few decades.

I am sure that you know that for a generator to charge, the engine has to be turning some revs, 800 RPMs at idle will not charge the battery. It needs closer to 1500 RPMs.

I always use larger in diameter battery cables than the rig came with from the factory. I use OO sized cables for all of my six or eight volt applications. If you live in sunny southern California, you might not need any larger than 1 gauge, but if you live in Truckee, go with OO. It gets fairly cold there.

Cables that are too small & corrosion in the starter circuit connections, including the negative battery cable to frame connection, are the usual culprits for slow starters.

So to recap, I suggest that you install a good six volt battery & some new large diameter battery cables, all the way from the battery to the starter.

IHTH, Cpt Logger.

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MikeG1949 View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote MikeG1949 Quote  Post ReplyReply Direct Link To This Post Posted: 11 June 2022 at 8:24am
Bruce and cpt logger:
We took Bruce's advice and returned it to a 6 volt system. In the process we found it had a bad voltage regulator.  Now it starts and appears to be returning power to the battery.  However, it still starts hard, i.e. grind, pause, grind,  pause, start.  I'm ok with that but fear that we will be out with it and it won't start. So, other than pushing it, is there a way that I could use a 12 volt jump starter battery pack, or jumper cables off of a 12 volt battery to safely start it and not damage the system? 
Mike G 1948 S/N 197198
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Post Options Post Options   Thanks (0) Thanks(0)   Quote TERRY Quote  Post ReplyReply Direct Link To This Post Posted: 11 June 2022 at 8:42am
I believe that will work (12v) to jump. Only circuits working are starter, coil, distributor and gas gauge. Keep lights off .
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Post Options Post Options   Thanks (0) Thanks(0)   Quote ace32107 Quote  Post ReplyReply Direct Link To This Post Posted: 11 June 2022 at 10:23am
If you have not replaced the starter I would check out all the bushings in your current one. Make sure all your grounds are good as well. good call replacing the voltage regulator. Most voltage regulators can be adjusted to output 9.6 volts for an 8volt system. But I agree with everyone's suggestions here, chnge out cables and fix grounds and return to 6 volt you should be able to run 6volt. Check your ignition cables as well especially if it was changed in the past.
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Bruce W View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Bruce W Quote  Post ReplyReply Direct Link To This Post Posted: 11 June 2022 at 11:28am
  Yes, you can jump-start it with a 12-volt jump box, but do it quickly and carefully. But that’s still a band-aid, not a cure. Find the problem and repair it, make the 6-volt system work like it should, and it will start like mine and many others do. 
BW 
It is NOT a Jeep Willys! It is a Willys jeep.

Happy Trails! Good-bye, Good Luck, and May the Good Lord Take a Likin' to You!

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Post Options Post Options   Thanks (0) Thanks(0)   Quote MikeG1949 Quote  Post ReplyReply Direct Link To This Post Posted: 11 June 2022 at 5:54pm
Took it out for a car show, 16 miles round trip.  Started good, purred like a kitten right after starting.  It would not hold low idle when running off of the 8 volt battery.  Thanks for the advice on confirming the jumpstart instructions if needed.  BTW, won two awards. Volt meter on the battery showed 6.42 V after driving to and from the show. I keep it on a tender so we’re good. 
Mike G 1948 S/N 197198
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Post Options Post Options   Thanks (0) Thanks(0)   Quote ndnchf Quote  Post ReplyReply Direct Link To This Post Posted: 13 June 2022 at 9:16am
I made this short video a couple years ago that shows how fast a properly set up 6v system will crank when everything is right.  Good, clean and properly sized ground cables are essential.


1948 CJ2A - It goes nowhere fast, but anywhere slow.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote MikeG1949 Quote  Post ReplyReply Direct Link To This Post Posted: 13 June 2022 at 8:39pm
Thanks for the video.  I already have heavy positive cables that were supplied during the restoration.  I will add the ground from the starter mounting bolt and polish up the positive contact at the starter.  Thanks again. 
Mike G 1948 S/N 197198
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Post Options Post Options   Thanks (0) Thanks(0)   Quote MikeG1949 Quote  Post ReplyReply Direct Link To This Post Posted: 14 Aug. 2022 at 2:48pm
First thanks to all who have weighed in on providing solutions.  Update:   I had the generator and new regulator (made in America) provided and matched by a shop specializing in that.  I also installed a new 6 volt battery.  I have a battery tender on the battery and it holds good charges and reads as fully charged after driving.  I timed it using a vacuum gauge, and it now starts really well.  If I shut it off, the H2O temperature shows about 145 and it will immediately start well with a slight resistance, but well.  However, if I leave it for a bit the temperature raises to approximately 165 and then it does not want to turn over.  Any ideas on what to try next? 
Mike G 1948 S/N 197198
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Post Options Post Options   Thanks (0) Thanks(0)   Quote cpt logger Quote  Post ReplyReply Direct Link To This Post Posted: 14 Aug. 2022 at 9:53pm
What exactly do you mean by "it does not want to turn over"?

Does the engine just sit there, or does it spin but not start?

Have you messed with anything on it recently, points, condenser, carburetor, spark plugs, +/or wires?
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Post Options Post Options   Thanks (0) Thanks(0)   Quote MikeG1949 Quote  Post ReplyReply Direct Link To This Post Posted: 15 Aug. 2022 at 2:08am
By "not turn over" I mean the engine seems to be almost frozen, like the battery is dead, like it has all of a sudden got out of time and has no cranking power, it does not spin.  I have not replaced any of the parts you mentioned, i.e. condenser, points, wires, plugs or carburetor, nor a new distributor cap.  It starts fine when not hot.  And, after I run it and the temperature gets up to around 140 and I shut it off.  It will start fine then.  But if it sets, like when we run into the grocery store to buy 5 items and the temperature rises then it will not spin.  The battery is maintaining a full charge though all of those examples. I see on the forum others suggest the condenser.  Is there a way to check the condenser?  One person mentioned they had to try several to get a good one.  When I asked my parts store if they had one, they told me they could not look anything up from 1948...
Mike G 1948 S/N 197198
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Post Options Post Options   Thanks (0) Thanks(0)   Quote bight Quote  Post ReplyReply Direct Link To This Post Posted: 15 Aug. 2022 at 7:12am
do a search here for condenser. you shall then receive your requested answer. lots of them. i think the part number will show up somewhere also for the blue streak condenser. 

Edited by bight - 15 Aug. 2022 at 7:14am
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Michaeltru Quote  Post ReplyReply Direct Link To This Post Posted: 15 Aug. 2022 at 7:47am
Condenser would be suspect is engine was hot and was not firing until cooled down.  But your engine won’t turn over when hot.  I would guess starter is suspect. Or wiring grounds. Or wiring. Foot starter button?  Battery?

Edited by Michaeltru - 15 Aug. 2022 at 7:48am
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Jeff J Quote  Post ReplyReply Direct Link To This Post Posted: 15 Aug. 2022 at 8:10am
Sounds temperature related to me. Starter or wiring near the engine end would be my guess. I had an airplane act that way with me. The armature in the starter was burned out. 
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