car not charging

stan35

stan35

Member
Took the '35 Cabriolet for a drive today and discovered that the ammeter showed no charging. The gauge showed a discharge when the lights or brake peddle were activated. Had the same condition in July of last year. At that time I brought the generator and regulator to a recommended auto electric shop. The next day they called and said the regulator was no good. I purchased a new 12 volt regulator (car was converted to 12 volts by the previous owner) and installed it in the car. All was fine until today. I suspect that it may be the regulator again. Before I call the electric shop I would like to test it. Would appreciate any information on how to jump around the regulator. If it is the regulator I hope the repair shop will stand behind the product. I don't know if there is a guarantee. I will call them tomorrow. Thanks.
 
What generator do you have---what regulator ??, it is not stock, there can be many variations -can you post pictures
 
Kurt NJ- The previous owner had the original 6volt generator converted to 12 volts when the car was restored 3 years ago. The regulator that I purchased last year is for a GM 12 volt. That is the regulator that the electrical shop said I must use with this system. It was the same as the one that went bad . Had the same numbers and appearance. Thanks, Stan
 
In order to test it you need to know how it is wired, usually Ford worked by putting power to the field, GM by making a ground for the field ---internally the ford type had the field grounded, the gm had the field connected to the non grounded brush, this is why I asked for pictures, they are tested different

Does the generator have a cover band, or are there narrow slits that are exposed ---id a wire connected to the end plate or do they all come out of the housing

this is one of the problems with "modifications" --they are done many different ways
 
Kurt in NJ-The generator does have a band around it. There are two wires coming out of the center top of the generator. The previous owner said the generator was original and was converted to 12 volts during the restoration. I suspect the problem is the voltage regulator again. I only have about 700 miles on this regulator in the last 8 months since I installed it. Can I jump around the regulator while watching the ammeter to see if it shows charge? How is this done. I want to be sure it's the regulator before I call the shop that I purchased it from. Thanks again.
 
Now I understand why a gm regulator, but still some more information needed, if you take the cover band off is there still a 3rd brush ---and is there a wire connected to it ---or are there 2 wires connected to the non grounded brush

the 2 wires coming out the generator, one should be thicker wire, this is the power out, goes to ---I'm guessing --"ARM" connection on regulator, the smaller wire to "FLD" -----but depending on type of regulator and if the internal wiring of the generator the amperage needs control, if the 3rd brush is still used the amperage is limited by the 3rd brush, ---grounding the "fld" wire (best to disconnect from regulator to prevent regulator damage) should make it charge ---if it is still using the 3rd brush the car can be run that way, if the internal wiring has been modified the just use 2 brushes it can only be tempoary for diag to prevent generator damage---the generator will run flat out too many amps and cook in a short time, and over voltage (burn out bulbs quick, cook battery)

is it a 2 unit regulator, (square) or rectangular 3 unit regulator
 
Kurt in NJ- The regulator is black rectangle with three tabs. The 3rd brush is not operational according to the previous owner. Today I checked the connections at the regulator which were clean and tight. I then tapped the box with my wrench. After that I jiggled the 2 wires from the generator to the regulator, the are connected with wire nuts and taped. After that I started the car and to my surprise the ammeter showed charging. The needle responded according to the acceleration. Now I don't know which of my actions caused it to start functioning. I will keep an eye on the ammeter to see if it stops again. Do you know the procedure to jump around the regulator to see if that is the problem in the future? Thanks for your assistance
 
"wire nuts and taped" sounds like one source for problems. May need to get some good connections (non-plastic type wire nuts) and heat shrink them.
 
Wiring should at least be made with crimp type terminal connectors. Even butt splice crimps are better than twisties. If the car sets for a long period, it sometimes loses the residual magnetism in the field pole shoes that starts it generating. A three pole regulator will also have a cut out relay as one of the three poles along with the regulator pole & current limiter pole. They can sometimes stick and not let the generator on line after start up.
 
Will get better connectors to eliminate the possibility of poor connections. I will also watch the ammeter to see if the problem arises again. The car is driven at least twice a week weather permitting. Would still like to know how to jump around the regulator to eliminate that as a possible problem if needed while troubleshooting. Thanks to all who responded.
 
stan35 said:
Will get better connectors to eliminate the possibility of poor connections. I will also watch the ammeter to see if the problem arises again. The car is driven at least twice a week weather permitting. Would still like to know how to jump around the regulator to eliminate that as a possible problem if needed while troubleshooting. Thanks to all who responded.
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You can't "jump around the regulator". You need a cutout to disconnect the generator at low speed or idle or the generator will start to run like an electric motor. The fan belt will stop the generator from running and when the engine is shut down you will melt the solder in the armature. G.M.
 
GM- In my last post I,m asking how can I test the regulator to see if it is working. Is there a procedure to go around the regulator momentarily while watching the ammeter. This is for troubleshooting purposes only. I wouldn,t drive the car this way. Thanks.
 
stan35 said:
GM- In my last post I,m asking how can I test the regulator to see if it is working. Is there a procedure to go around the regulator momentarily while watching the ammeter. This is for troubleshooting purposes only. I wouldn,t drive the car this way. Thanks.
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I think Kurt answered your question in post #7

Bob
 
Stan, Depending on which way the field wires inside your early ford generator have been connected/modified you can bypass the voltage and current regulator but with the cut out still connected by doing the following tests. This will test your generator output. For a GM system as you suggested it is, disconnect the field wire from the field terminal on the voltage regulator and ground it. Rev up the engine and check the ammeter for amps charge. The more you rev it the higher the charge will be as there is no regulation. If the fields in the generator have been connected as for the ford system then remove the field wire from the regulator and connect across to the armature terminal on the regulator and do the same test. If there is still no charge then more than likely the generator is at fault. If there is a charge then the regulator (contacts) could be the problem. The cut out could also give problems. There are three units inside the regulator box, a voltage regulator, a current regulator and the cut out. Good luck, regards, Kevin.
 
Took the '35 out for a spin today and all is well. The ammeter functioned properly. If the problem occurs again I will troubleshoot starting with the regulator per the instructions given in the previous posts. Once again thanks for the response.
 
stan35 said:
Took the '35 out for a spin today and all is well. The ammeter functioned properly. If the problem occurs again I will troubleshoot starting with the regulator per the instructions given in the previous posts. Once again thanks for the response.
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f this car was still 6 volts with the original type parts the problem could be found in 5 minutes. These cars have worked perfect for 80 years and still work perfect on 6 volts, I don't get all this 12 volt mania. G.M.
 
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