12 volt conversion wiring diagram

[Los_Control]

The 6 volt starter will work fine in 12 volts, you really do not want to stand on the starter and crank it for long periods.

We have a old international truck that got converted 15 years ago and is still running the original 6 volt starter.

 

When your starter is worn out and needs replaced/rebuilt, then would switch to 12 volt.

And napa or any good parts store should be able to help. The mopar flathead sixes were made up into the 60's and even 70's on some industrial applications.

And I would imagine the starters will interchange. I imagine you may need to go to a push button if you have a foot  starter. Dunno.

[RonaldC]

Jon, If I told you it was a total blast, it still would not accurately describe it! Loving it! just put up a couple more recent pictures of it.

Otto,

Everything I read said no need to change, original starter can handle the additional voltage. So, reluctantly I went with it figuring either way (meaning it handled it or it didn't) I would be changing the starter. Much to my surprise, it works fine. I would even go as far as to say it works better then it did before. Now that being said, I do not stay on it, and on it, when it is cold. But you shouldn't be doing this on a modern starter either though. But when starting, I engage it for about 3 seconds-ish, let off, and then repeat as needed. Truthfully, converting was best thing for me and the truck. It starts better, it runs better, it does everything better in my opinion. In short, I wouldnt change it unless just had too.

 

Now just for general update/discussion, I have moved into the lighting phase of the truck. Had to since changing over to 12 volt. Only thing lacking now is the rear turn signals. Have tail lights but no blinky blinky. At the risk of offending some, I added halo running lights and turn signals when I swaped the headlights. wired them to come on with parking lights. And I have to tell you, I actually kind of like it. Truck is running and driving better then it has in a while I am sure, maybe ever......

[John H.]

      I've got a couple of questions if anyone is still following this post? The wiring on my 53, 3/4 ton is shot to the point of being a fire hazard. It is no surprise to me as it was something I noticed when I looked the truck over before I purchased it. The truck was supposed to have been converted to a 12 volt system and had a 12 volt battery in it. The quality of this conversion is questionable to me. Fortunately, there is a battery disconnect below the driver's seat, which I use in conjunction with disconnecting the battery after I occasionally start and run the vehicle. Brakes and some other issues have kept me from getting it out on the road since I brought it home over a year ago.

     Regarding the wiring. This truck has a positive ground system. Being as it is converted to 12 volts should it be a negative ground? When I first got it I noticed that the radio was in the "on" position but did not work. When I turned it "off" the tubes lit up and I got some static. The same with the ignition switch. Turning the switch in the off position and hitting the floor starter starts the truck. Turn the switch in the on position and the truck shuts down. I get it that the ignition switch may have been incorrectly wired but that doesn't explain the radio, at least not to me. Gauges? I don't know what to believe with them and would like to locate the gentleman here on the forum that rebuilds them for when I get my old blue buddy rewired. Does anyone have any ideas as to what I am looking at here?

     Rewiring, my last issue. Thanks to input I've garnered from folks on this forum I have my shop wood / coal furnace up and running. Thanks to all who added input. My immediate project is a rewire on my 47 Knucklehead project. It is a project I have to finish up here, and though the wiring is not as involved as a 53 pickup I have no qualms about tackling it. That said, the Knuck's wiring is a cloth covered kit which pales in comparison to the cost of that of a pickup. What are the best suppliers out there for sourcing the cloth covered wire, terminals, relays, and other components one needs to build their own harness? Thanks. 

[RonaldC]

John,

 

1st, yes, you need to have a NEGATIVE ground. Everything is working in reverse because the circuits are in reverse. Meaning you are actually turning the radio "on" when you are turning it "off". I would not suggest trying to chase any problems until you correct the known issues. You may find that most of it is wired correctly once you fix the ground.

 

Gauges will need to have a resistor in order to work with the 12 volt system, here again making them far more reliable. I bet they work great when the truck is turned off. Well, probably not but you get the jest. As far as rebuilding them, there is a guy here, but cant remember his name. I want to say he is also on E bay. If not, and you are willing to part with some of your kids college fund,  Red Line Gauges in southern California looks to do some pretty high quality work.

 

To the cloth wiring. Me? I pulled it all out. I don't trust things that actually look they are about to catch fire. Historically dust and electricity are not a good match. Or maybe they are. (pardon the pun). I ordered a complete kit from Yogi's online and replaced it all. Done. No more worries or electrical problems.

 

Now the Knucklehead? You sir clearly have impeccable taste. Early 50's Mopar AND a 47 Knuckelhead? You friend are a gentlemen among gentlemen. But to the point. I don't know who does. Would suggest contacting my local HOG chapter. Those guys are ALL ABOUT breathing life into lost treasures.

 

Hope this help, let me know if I can be of service.

 

Ronald C.

[John H.]

     Thanks for the reply, Ron. I kind of figured something was with the ground, but wasn't willing to just start taking chances with the wiring being what it is. I also appreciate the compliment regarding the bike and I have what I need to wire that. I am looking for the wiring components for the old trucks. Thanks again.

 

John H.

 

     I've got a couple of questions if anyone is still following this post? The wiring on my 53, 3/4 ton is shot to the point of being a fire hazard. It is no surprise to me as it was something I noticed when I looked the truck over before I purchased it. What is kind of strange is that the truck was supposed to have been converted to a 12 volt system and had a 12 volt battery in it. Fortunately, there is a battery disconnect below the driver's seat, which I use in conjunction with disconnecting the battery after I occasionally start and run the vehicle. Brakes and some other issues have kept me from getting it out on the road since I brought it home over a year ago.

     Regarding the wiring. This truck has a positive ground system. Being as it is converted to 12 volts should it be a negative ground? When I first got it I noticed that the radio was in the "on" position but did not work. When I turned it "off" the tubes lit up and I got some static. The same with the ignition switch. Turning the switch off and hitting the floor starter starts the truck. Turn the switch on on the truck shuts down. I get it that the ignition switch may have been incorrectly wired but that doesn't explain the radio, at least not to me. Gauges? I don't know what to believe with them and would like to locate the gentleman here on the forum that rebuilds them for when I get my 4-wheeled buddy rewired. Does anyone have any ideas as to what I am looking at here?

     Rewiring, my last issue. Thanks to input I've garnered from folks on this forum I have my shop wood / coal furnace up and running. Thanks to all who added input. My immediate project is a rewire on my 47 Knucklehead project. It is a project I have to finish up here, and though the wiring is not as involved as a 53 pickup I have no qualms about tackling it. That said, the Knuck's wiring is a cloth covered kit which pales in comparison to the cost of that of a pickup. What are the best suppliers out there for sourcing the cloth covered wire, terminals,  

[John H.]

Hey Ron,

 

       By the way, nice truck!

 

John H.

[RonaldC]

Thank you. I am kind of partial to old Dodges (and HD) myself.

 

Which components? Most all existing will work with 12volt, just have the resistor inline. I used Vintage Auto Garage for the conversion pieces. Maybe could have it done it diff for slightly less, but not much less.

http://www.vintageautogarage.com

[Don Coatney]

Last I checked "off" is an open circuit meaning the power is removed, and "on" is a closed circuit meaning the circuit is complete irrelevant of polarity or voltage. 

[RonaldC]

But when its off, it is still has a power source via the Positive "ground'. My guess is when its in the on position, there is no ground to be found.

 

But in all fairness, I cant say I have ever tried to wire it backwards to test my theory so I am far from a subject matter expert here.

 

[John H.]

Ron,

     Thanks for the link. I am looking for the cloth covered wire and other components necessary to create a clean and safe 12 volt system. The only change I may be looking at would be an alternator, I believe?

 

Don,

     Technically Sir, you are correct. Logically, I took the easy route and I am a cad.

[maok]

1 hour ago, RonaldC said:

But when its off, it is still has a power source via the Positive "ground'. My guess is when its in the on position, there is no ground to be found.

 

But in all fairness, I cant say I have ever tried to wire it backwards to test my theory so I am far from a subject matter expert here.

 

 

Your guess is incorrect. When the switch is off (open circuit), there is no power regardless of which side the +ve or -ve voltage is on.

 

A 12v system, just like a 6v system can be +ve or -ve ground. Its some of you devices that care about the polarity ie. radio.

My '28 Chrysler is 12v positive ground, the only two things that need attention is the wiper motor and the LED stop lights. Everything else does not care which way the electrons come from.

[John H.]

     I am still confused as to how to start diagnosing this issue? Mr. Coatney got me to thinking that pulling the ignition switch and checking terminals would be a start. I was working on the theory that flipping the battery ground may correct the problem but I don't want to blow any of the gauges by chasing a hunch. I have nothing good to say about the guy I bought the truck from and know for a fact that any work he did was just enough to get it running to get rid of it. No sweat, though, it will get straightened out.

[RonaldC]

For me, I always try to start with the obvious issues and work backwards into the “root”. If I was concerned about causing damage down stream, may be worth it to remove any of the respective wires from said device. I think there is only 2 at the most per device anyway, no?

 

All of that being said though, the amount of time vested in chasing somewhat of a moving target may be better spent on just starting over and replacing it all. To be clear though, I would have to be compelled to believe there are multiple multiple issues, not 1 or 2 problematic functions. My experience with “clean up” of others “failed attempts” has been I inadvertently create another problem trying to diagnose the 1st one, bumping loose wires or things of the sort. 

 

Now, all that said, and not that I am professing to know the extent of your situation, nor am I “huge” proponent of giving up and starting over, but to be candid, there isn’t just a whole lot to wiring a 50’s model pickup. But what I am advocating is make sure you are being efficient with your resources. 2 or 3 days of my time, plus material, when I could clean it up in a day? I’m trouble shooting. 3 or 4 weeks trouble shooting when I could have all new, done right, done my way, all for 2 or 3 days of my time, plus material? Yep, no brainer.

 

My advice is grab a bucket of ice and a couple beers. Start with fixing the known issues. If I make some real progress by days end, stay with the clean up initiative. But if I’m no closer, and/or out of beer by day 2, I’m really thinking seriously about will my continued efforts prove to be in vain......  

 

Hope this helps, or at least gives you food for thought.

 

cheers!

[tanda62]

John,

I am with Ron on this one.  Chasing down electrical gremlins can be like Alice going down the rabbit hole.  There just aren't that many wires in these trucks so changing them out is not as big a deal as with many vehicles.  I got cloth wires from Tom's engine barn and really like the quality.  They are coated so dust is not an issue.  The fuel gauge needs a voltage reducer and those can be had from many sources, got mine from Amazon via Eckler's.

Here is a link to some helpful information - http://dodgepilothouseclub.org/know/wiring_harness/wiring.htm

 

Good luck!

Tom

[FlashBuddy]

Tom's Engine Barn seems to have good prices, though I haven't shopped around. But why does he post crappy photos?

 

I'm hot for yellow. Tom's pic vs. My pic w minor adjustment. It had to be done.

 

 

Edited January 15, 2018 by FlashBuddy
Typo

[John H.]

     I appreciate the input and I am going to start laying out a materials list for what I need. Tom's Engine Barn appears to be a good choice to start and I found some other good info and sources of components, as well. As just an F.Y.I., I happened across Vintage Auto Garage and they carry a 6 to 12 volt conversion kit  http://www.vintageautogarage.com/1947-55-Chrysler-6-to-12-Volt-Conversion-Kit-p/c4755k.htm.  I would imagine the folks on this forum have the knowledge to put the parts together a bit cheaper but the info may still be usable? Their site also offers an e-mail advice link on doing the conversion          http://www.vintageautogarage.com/v/vspfiles/files/Free 6v-12v-report-10.14.pdf?inf_contact_key=c526d0954042977fff5e9e1e06e82d5bce6c735d478817390861cbcdfae8632a

 

 I am going to stick with cloth covered wire for this project and will replicate the gauge of the wire I am replacing. As has been stated here in these posts I don't expect the rewire to be rocket science and, you all are right, it is the best way to lure the gremlins out of the beast. The roads here in the Ozarks are just awesome and I want to get my truck up and running so I can enjoy them while I finish turning out a couple of bike projects I've been neglecting. A plastic wiring harness on the truck would get me there, possibly a bit cheaper and quicker, but I am hoping that in another couple of years I'll have the desire to do a frame off resto on this truck. I have seen the work some of you guys turn out and can only wish I could be as talented. When I do turn my evil eye to my truck I'll feel better knowing that I have already done the wiring the right way. I appreciate the help, guys.

 

     John

[RonaldC]

The Vintage Auto Garage kit was the exact kit I used. I would agree you may be able to piece together your own kit, but again for me, ease and simplicity is worth the relatively inexpensive purchase price.

 

Good luck and should you run into a problem, don’t hesitate to reach out to the fellow Mopar lovers around here. Though not an expert, I’m always happy to help where I can.....

[John H.]

Thanks Brother!