kouseneric39 Posted April 30 Report Share Posted April 30 I have a 39 dodge d10 I bought the car running and drive but the generator wasn't charging.i took it out and installed new brushes.still no luck.what would be the course of action to track down if it's something other then the generator being shot. Quote Link to comment Share on other sites More sharing options...
soth122003 Posted April 30 Report Share Posted April 30 Follow the manual. There is only about 3 things that can cause the no charging. 1. Generator 2. Voltage regulator 3. Bad wiring or bad grounding. The repair manual has the tips and troubleshooting techniques to figure out what might be wrong. The problem with the manual is it only addresses each component separately. It doesn't address the problem of not charging, but addresses each component not working properly. So if your wiring is good, use a multimeter and start with the generator and see if it is putting out the prober voltage to charge the battery. If it is then check the voltage regulator. When you find the component that is not working properly, use the manual to troubleshoot it. The voltage regulator is easy to check and fix or replace. The generator... About the only thing you can't check on the generator, according to the manual, is the armature check. The VR is about $60-$80 I think and the genny can be rebuilt at most starter generator shops for about $150. If you like originality, fix or replace the items that are bad. If not replace the VR and genny with a 6v pos ground altenator. https://www.ebay.com/itm/335208751824?itmmeta=01HWR0XZJZTWG5B21DCZ12BBPF&hash=item4e0bffa2d0:g:FAgAAOSw1JVaHKCw This is the one I put in my P-15. My last 2 genny's the armature went bad and I just said the heck with it. Joe Lee 1 Quote Link to comment Share on other sites More sharing options...
Ivan_B Posted April 30 Report Share Posted April 30 What kind of troubleshooting have you done so far, to determine that it is not charging? Quote Link to comment Share on other sites More sharing options...
greg g Posted April 30 Report Share Posted April 30 Might be the voltage regulator. Simple test, start the car and use the hand throrrle to up idle to 800 or so. Use a jumper wire to ground the field terminal. The field terminal is the smaller diameter generator terminals. The ammeter should peg to full charge. If it does the generator is working, and the fault is in the regulator and or it's wiring. If the regulator cover will come off, remove the cover and clean all these points. Retest. If still no charge, check the regulator wires and connections. 2 Quote Link to comment Share on other sites More sharing options...
Jerry Roberts Posted April 30 Report Share Posted April 30 Try polerizing the generator first . It is easy and fast and costs nothing . 2 Quote Link to comment Share on other sites More sharing options...
kouseneric39 Posted April 30 Author Report Share Posted April 30 3 hours ago, Jerry Roberts said: Try polerizing the generator first . It is easy and fast and costs nothing . What's the process of polarizing the generator I'll be doing all of this stuff tommarow Quote Link to comment Share on other sites More sharing options...
Sam Buchanan Posted May 1 Report Share Posted May 1 You do have a service manual, right?? Quote Link to comment Share on other sites More sharing options...
kouseneric39 Posted May 1 Author Report Share Posted May 1 Yes 1 Quote Link to comment Share on other sites More sharing options...
greg g Posted May 1 Report Share Posted May 1 Or in the case of a vehicle with a new fully charged battery, that starts right up, it won't charge till it needs to. Quote Link to comment Share on other sites More sharing options...
Los_Control Posted May 1 Report Share Posted May 1 I was thinking same thing as @Jerry Roberts seems like you always needed to do something to get them to start charging when installing .... I guess polarizing is correct term .... I would have to look it up online to see what to do .... seems you ground or cross some wire with it running. I'm just not the guy to mess with 6V and switched to a 12V alternator ..... knowing my generator needed work and was not producing enough to charge. Quote Link to comment Share on other sites More sharing options...
kouseneric39 Posted May 4 Author Report Share Posted May 4 Im currently in the middle of doing my 12 volt conversion few questions can I retain my key switch by cutting of the big cable that goes to my old coil just using the two terminals on the factory ignition switch?? Quote Link to comment Share on other sites More sharing options...
desoto1939 Posted May 4 Report Share Posted May 4 if you cut through the entire cable and then cut the internal wires to short then you might have a pbm with getting new wires attached to the switch. I stil have the 6v positive grd wire system in my 39 Desoto. Also remember that if switching to neg ground how you need to connect the wires to the coil. The switch in your 39 Dodge is just completing the electrical circuit to provide power to the coil and then to the dizzy. I have owned my 39 Desoto which is a sister car to your 39 Dodge for over 35+ years. I have not switch to an alternator and still have the 6v gen and starter. Might consider converting to a 6v positive grnd alternator and then use a converter to power anything that you need for 12 volts. This is a lot cheaper and then you still have the originality for your 39 Dodge. Just my 39 cents worth of input. Rich Hartung Desoto1939@aol.com Quote Link to comment Share on other sites More sharing options...
kouseneric39 Posted May 4 Author Report Share Posted May 4 Beautiful cars I'm not to worried about originality engine wise based on this car being swapped with a newer 53 dodge engine.so I decided to get am 12volt conversion the eventual engine swap will need it regardless.im thinking I may just put a switch to the alternator exciter wire and the coil without the key. Also trying to figure out witch wire from the sending unit to put the 6v seltep down in Quote Link to comment Share on other sites More sharing options...
kouseneric39 Posted May 4 Author Report Share Posted May 4 Found a key switch the fits in the dash for 12v. Also on a 39 the wiper motor power feed wire is witch one on the terminals on the engine my shop manual has colors but my wires don't lol Quote Link to comment Share on other sites More sharing options...
desoto1939 Posted May 4 Report Share Posted May 4 In the picture going from left to right the contacts are marked as A, B, C. Go to your service and parts book for your car adn then go to the wire diagram. It will show you which wire is connected to your wiper switch and the power source. If you do not have these basic two manuals then you will need to have them so that you can understand how your car is wired and how to fix items that need repair. each of the wires will then connect back to the wiper switch and each terminal is also labeled as A,B or C. you will have to trace the power source from the switch. Rich Hartung Desoto1939@aol.com Quote Link to comment Share on other sites More sharing options...
kouseneric39 Posted May 7 Author Report Share Posted May 7 Unfortunately my sevice manual doesn't have the wiper motor in the wiring diagram Quote Link to comment Share on other sites More sharing options...
desoto1939 Posted May 7 Report Share Posted May 7 Here is the wiring diagram from my 39 Desoto it basically should be the same for your 39 Dodge. Part AA is the electric wiper motor. Note the A,B,C wires connected to the wiper motor. The wire number 41 supplies power to the wiper switch and connects to Y the fuel guage on the dash. This should help you get to know your car. The 1939 Chrysler, Desoto and Dodge basically used the same wiring pattern. This page was taken out of my 1939 Supplemental service manual for the 39 Desoto. Rich Hartung Quote Link to comment Share on other sites More sharing options...
kouseneric39 Posted May 9 Author Report Share Posted May 9 Thank you this still doesn't tell me the power wire from the switch that works the motor.the color of my wires is so gone I can't use that so time for my good old test light Quote Link to comment Share on other sites More sharing options...
desoto1939 Posted May 9 Report Share Posted May 9 6 hours ago, kouseneric39 said: Thank you this still doesn't tell me the power wire from the switch that works the motor.the color of my wires is so gone I can't use that so time for my good old test light kouseneric39: I am sorry that you did not get the complete answer to your question. At first you stated that you did not have a wire diagram for your 39 Dodge so I took my time and copied the wire diagrahm and the wire number section so you would know what wires went to from the switch to the wiper motor. even my shop repair manual does not specifically state which is the power wire sending current to the wiper motor. So yes now that you know where each wire should be attached to the switch and to the wiper motor you can now use your testing lamp to help identify the power source. i did tell you that the power to the switch comes from the fuel gage. Yes your wires might have changed colors but you will still have to look under the dash a physically trace which wire and color goes to each switch. Sometimes the best knowledge is received via the effort to learn by doing things yourself with a test lamp. Rich Hartung desoto1939@aol.com Quote Link to comment Share on other sites More sharing options...
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