azmichael1 Posted May 7, 2011 Report Share Posted May 7, 2011 (edited) deleted Edited October 10, 2012 by azmichael1 Quote Link to comment Share on other sites More sharing options...
1941Rick Posted May 7, 2011 Report Share Posted May 7, 2011 Use a single wire 40 - 60 amp alternator....fab a bracket to mount it.Change all the bulbs to 12 volt. If you have electric wipers upgrade to 12 volt. I changed my P12 over to 12 volt last year. I did not change the heater motor, just run it on low and medium speed. Overdrive sol is still 6 volt. The gas gauge has a light bulb in the BAT side of the gauge. this slows down the reaction of the gauge. You can get devices to drop the voltage, but this was a simple cheap way. Remove the regulator from the generator circuit and run the BAT wire to the alternator. Have you switched polarity yet? If not reverse the wires on the AMP meter. Quote Link to comment Share on other sites More sharing options...
slogger147 Posted October 27, 2011 Report Share Posted October 27, 2011 (edited) 1950 dodgestreight six gen swap to a 1995 dodge dakota alternator ? can it be done and how do you wire it up using the old wire harness? I know it internally regulated so i don't have to use the voltage regulator but can find anybody who knows how to wire it up already changed to twelve volt but still wire the same as 6 volt if that helpes Heres the wiring diagrame that I used to rewire it just need to add in the altornator Edited October 28, 2011 by slogger147 Quote Link to comment Share on other sites More sharing options...
Plymouthy Adams Posted October 28, 2011 Report Share Posted October 28, 2011 suggest you restudy the alternator..it should be of the type that is regulated by the on board computer...however all is not lost and one can adapt an electronic voltage regulator exteranally... Quote Link to comment Share on other sites More sharing options...
OldDad67 Posted November 28, 2011 Report Share Posted November 28, 2011 Here's some stuff I've collected over the years that might be of help to you. Wait! I have a positive-ground GMC, what do I do? This so easy, you'll kick yourself for not having figured it out on your own. All you have to do to convert that Jimmy to negative ground is: 1. Disconnect the battery (VERY important first step) 2. Reverse the wires on the coil 3. Reverse the wires on the ammeter 4. Reverse the battery cables. While you're at it, why not switch the ground cable from going to the frame to a starter mounting bolt or the transmission? It's better than the frame. 5. Put all your tools away and sweep the garage floor, because you are DONE. Oh, yeah. Power up the system to see if you did it right. Easy job. By the way, this method works for Fords, too (should you have one laying around). 12 volts, but looks all original Okay, this one is a little harder, but still pretty easy. Even a Marine can do it. This method assumes you have either the original wiring harness, or you have replaced the original harness with a new 6-volt harness. Is your 6-volt harness adequate to convert to 12 volts? Yes, because the 6-volt system produces twice the amperage of the 12-volt system. So, the 6-volt harness is actually heavier than needed for the 12-volt conversion. With that out of the way: • Disconnect and remove the 6-volt battery. If you discard it, make sure you do so properly. Used Lead acid batteries are hazardous waste, so please dispose of them properly -- it's the law. • Remove your 6-volt generator. • Replace with a 12-volt generator. I got mine from a guy hotrodding a '57. It fit perfectly and looks almost identical to the original 6-volt unit. • Remove the 6-volt voltage regulator and replace it with a 12-volt one. Again, you can probably use the one that came with the 12-volt generator you found. • OR, if you want to be anal and maintain strict originality, you can use your 6-volt generator -- just take it to a good electrical shop and have them replace the 6-volt field coils with 12-volt ones. Just don't forget to replace your voltage regulator... • Replace your 6-volt bulbs (headlights, taillights, parking lights, dash lights, dome lights, etc) with 12-volt bulbs. • Put a ballast resistor* in the line between the ignition switch and the coil • Put a voltage reducer* in the power line to each 6-volt accessory switch (radio, heater, etc) • Put a Standard Ignition* in the line to the gas gauge. • Install a 12-volt coil • Install a 12-volt battery that fits your battery tray (duh). • Power up the system and check it out. 12 volts, but with an alternator This one isn't quite so easy. I tried this the first time around and it took a few tries to get it right. At any rate, this approach is pretty widely used and has a lot of advantages, but you lose originality -- you have a big, ugly alternator sticking out like a sore thumb. Yuck. If you can live with that, here's what you do: • Disconnect and remove the 6-volt battery. If you discard it, make sure you do so properly. Used Lead acid batteries are hazardous waste, so please dispose of them properly -- it's the law. • Remove your 6-volt generator, coil and voltage regulator. • Install the alternator. You'll probably have to do some bracket modifications. • Use a DA plug on your alternator (because most modern alternators have built in regulators, this eliminates the voltage regulator on the firewall) • Take the "Batt" wire that used to go to the regulator and connect it to the red wire of the DA plug. • Connect the white wire from the DA plug and connect it to an "ignition" spot, either the ignition switch or the coil wire. • Wrap up the "field" and "arm" wires that used to connect to the regulator because you don't need them anymore. • Replace your 6-volt bulbs (headlights, taillights, parking lights, dash lights, dome lights, etc) with 12-volt bulbs. • Put a ballast resistor* in the line between the ignition switch and the coil • Put a voltage reducer* in the power line to each 6-volt accessory switch (radio, heater, etc) 1 Quote Link to comment Share on other sites More sharing options...
plymouth1947 Posted January 6, 2012 Report Share Posted January 6, 2012 how can I wire up my fuel gauge since it was positive ground? if I hook it up stock will it still read correct or is it going to read backwards? Quote Link to comment Share on other sites More sharing options...
Adam H P15 D30 Posted January 6, 2012 Report Share Posted January 6, 2012 Fuel guage does't see polarity. Hook it up normally, pos or neg ground doesn't matter. I used a Runtz voltage drop but I have heard of people running them on 12v with no issues. I error on the caution side. Quote Link to comment Share on other sites More sharing options...
40P10touring sedan Posted February 2, 2012 Report Share Posted February 2, 2012 Dumb question here, I just got my old style mopar 60 amp alternator that's external regulated. Wanting to do a 12v neg system conversion what is going to be the way I need to go....electronic reg or the older box type like my 40 has now -but 12v..or is it just a matter of preference? Thanks- Quote Link to comment Share on other sites More sharing options...
Plymouthy Adams Posted February 2, 2012 Report Share Posted February 2, 2012 buy the regulator matched to your alternator... Quote Link to comment Share on other sites More sharing options...
40P10touring sedan Posted February 2, 2012 Report Share Posted February 2, 2012 buy the regulator matched to your alternator... ...sadly the lessor oem look{oh, like the new alt is so oem, I know!}, but I believe your right...thanks for the valued input! Quote Link to comment Share on other sites More sharing options...
40desoto Posted September 6, 2012 Report Share Posted September 6, 2012 Im sorry if this question is stupid but did my 1940 Desoto coupe come without a fuse box? Quote Link to comment Share on other sites More sharing options...
greg g Posted September 6, 2012 Report Share Posted September 6, 2012 no just a fuse on the headlamp switch for ALL the lights, and maybe a 30 amp resetting circuit breaker up under the dash somewhere for the other stuff. Quote Link to comment Share on other sites More sharing options...
hillbilly4008 Posted September 6, 2012 Report Share Posted September 6, 2012 Im doing this conversion now. I did a motor swap and now need to run an electric fuel pump, So I'll be wanting fuse block (radio will be coming shortly) My question is, since i want the fuse block only to have power when key in on, can I get away with running a 10ga. wire from the + side of my fuel gauge to the + post on the fuse block? On my '53 Desoto the radio and heater fan both are powered through the + post on the fuel gauge. (I will be disconnecting both the radio and blower fan) Edit: I am installing a "runtz" on my fuel gauge, so technically I would be installing the 10ga. wire on the 12v side of the "runtz" Quote Link to comment Share on other sites More sharing options...
greg g Posted September 6, 2012 Report Share Posted September 6, 2012 Power the add on fuse box from the Acc terminal then it will be hot with engine on or when key is in acc position. The acc position will let you run the items powered through the box without the ign being on so you don't toast your points. You can feed it from the ign side of the coil or fuel gauge, but you are powering those with a 14 or 16 gauge wire, so pulling a feed through a 10 gauge wire off a 14 guage feed is kind of electrically backward. Run your 10 gauge from the acc terminal directly and with a short as possible run to the add on box, then you can run 10 gauge and down wire to the loads according to their draw and through an appropriate fuse. but if you are converting to 12V your resistance goes down, so you probably don't need 10 gor anything but the heater fan. most 12v stuff runs off 14 or 16 gauge. Quote Link to comment Share on other sites More sharing options...
Don Coatney Posted September 6, 2012 Report Share Posted September 6, 2012 Do you have your fuel gauge confused with your amp gauge? Amp gauge has two posts with heavy wire. Fuel gauge (on a P-15) has three posts with light wire. Fuel gauge should not be used as a power source for anything. Amp gauge Fuel gauge Quote Link to comment Share on other sites More sharing options...
hillbilly4008 Posted September 7, 2012 Report Share Posted September 7, 2012 Don, My '53 desoto wiring is nothing like that. The heater fan and the radio are both powered off of the fuel gauge. The wiper has its own hot wire. And the ammeter has a hot going in and two wires coming out, not sure what that third wire is... Quote Link to comment Share on other sites More sharing options...
40desoto Posted September 13, 2012 Report Share Posted September 13, 2012 Im sorry if this question is stupid but did my 1940 Desoto coupe come without a fuse box? Quote Link to comment Share on other sites More sharing options...
Dodgeb4ya Posted September 16, 2012 Report Share Posted September 16, 2012 The fuel guages on my 1946-8 Chryslers feed 6V from the fuel guage to feed the wiper "BAT" terminal and the starter crank push button circuits. Bob Quote Link to comment Share on other sites More sharing options...
Plymouthy Adams Posted September 16, 2012 Report Share Posted September 16, 2012 just another common tie point as there is not enough room on the ignition switch to bolt all the individual circuit feeds..it is not uncommon to pick up batt suppy from another component.. Quote Link to comment Share on other sites More sharing options...
Frank Elder Posted September 16, 2012 Report Share Posted September 16, 2012 Im sorry if this question is stupid but did my 1940 Desoto coupe come without a fuse box? No fuse box is correct.......fuse for headlight switch and radio, or clock if you have that option. Quote Link to comment Share on other sites More sharing options...
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