50 DS charging system

Its putting out less than 6.5v at a high idle or revving the engine. Not keeping the battery chared up enuf. Making for hard starting. Isnt there some way to bump up the voltage. Has an aftermarket regulator,dont see an adjustment on there unless its on the back of it

What kind of car is it?

1950 desoto

A fully-charged 6 volt battery should have 6.6 volts at rest, so I suspect your charging system is putting out nothing. Try this, take a short jumper and just very quickly jump the Field or "F" terminal on the regulator to ground. If you now show a high rate of charge, your regulator is defective, and if not, the generator is defective. Don't leave the jumper connected for more than a minute or so. New regulators can be purchased from NAPA; adjusting regulators is a bit of a specialty and requires ammeters, voltmeters, temperture sensors and the like and is rarely done, and then usually only successfully by someone who really knows this stuff.

There is a long section in the DeSoto repair manual on testing, cleaning and adjusting the voltage regulator. It is not especially difficult, the adjustments themselves are easy but you need a basic knowledge of electricity or electronics to understand it.

Best suggestion is to get a manual and try it, or take it to an auto electric shop with the right skills or take them your manual.

The battery only has about 5,6v at rest. I can disconnect the battery with the engine running, so I figured the charging system is working. That is why I asked if I could bump up the volts in the generator. I'll go out there and try the jumper and see what I get. What should I be getting for voltage output in a correctly working system anyway?

I took out the gen. to take to a shop

Just finished going through the charging system on a 49 Chrysler. Suggest taking the voltage regulater along to the electric motor people so they can test both working together.

Martin Lum

Thought about taking the regulator also. Had my son drop the gen at the shop.They said it was not putting out anything. Dont make sense to me. Engine would run with the neg cable off the battery. If it wasnt or isnt charging how could it run?

Your generator may have been putting out less than 6 volts. Not enough to charge the battery but enough to run the igniton system to keep the engine running. The shop may have said it is putting out nothing but it actually may be putting out enough to just keep the igniton system supplied. The test suggested of grounding the field terminal on the regulator and testing the voltage of the generator output at a little above idle speed is usually a very good test to rule out the generator or regulator. However, I think your battery may be defective with less than 6 volts with nothing connnected. Perhaps a shorted cell.

Before you check the charging circuit always start with a fully charged battery. Use an automatic or manual charger to be sure you can charge the battery. No load voltage using a digital volt meter shoudl be 6.3 to 6.6 volts. If you cannot assure this battery is good, start with a new one, fully charged, before checking the charging circuit. Good luck.

Joe, BCA 33493

Chaser,

Hopefully your local shop is able to help you out. If they have any trouble or you doubt their capabilities, feel free to contact me. I specialize in antique auto electrical units and am amazed at how much stuff I get in that have been to the "local rebuilder" and they get answers such as "can't be fixed or get parts" or just plain "don't know whats wrong". Nothing against your local guy (since I don't know who he is) just warning you of whats out there.

To answer your original question: Most regulators are labeled as non-adjustable, but they are all adjustable if you know what you are doing. Your generator, if original is a 2-brush unit and any adjustment would have to be made in the regulator to increase your output. However I don't believe this is your problem. Your regulator should be tested with your generator when done that way any adjustments can be made before you install. Also, make sure and get your battery fully charged while you are having your generator serviced.

If I can be of any further assistance, feel free to contact me.

Jason

Advanced Electrical Rebuilders

Grand Ledge, MI

jsmithaer@gmail.com

1-866-228-0218

I asked my son last night if he watched them do the test. He said yes, it was putting out 3v. so that satisfied me. So now I am waiting to get the gen back next week

Keep in mind I am not trying to insult your rebuilder or cause friction between the two of you, but just trying to help educate where I can. I've had too many people in my shop repairing an item that they've already paid someone else to fix. It gives rebuilders like me a bad name.

With that said, It is not possible for your generator to charge 3 volts. His tester should have a battery source much like in the vehicle. When testing the generator, if it doesn't charge he will show the battery voltage as if the machine was not on which should be 6 to 6.5 volts. The only way to show 3 volts is if there was a major short and the heavy current/amp draw drew the battery down to 3 volts or his battery is severely discharged to start with (not good either). If that was the case there would be smoke, odor and melted wires quickly. And we all know that would not be considered charging.

Any chance he may have said it was charging or discharging 3 AMPS? Seems more likely. If a generator will only discharge 3 amps, thats a good sign that your fields are drawing current and doing their parts but there is another problem in the generator.

Anyway, hope I'm not boring or frustrating you, but if I can help, feel free to contact me.

Jason

Jason your not boring me all. Only being 50 yrs old,6V is way beyond my experience. That possibility can also go along with that shop. Insult the builder all you want.Might not bee an insult at all . I am new to this area and have'nt been able to get to now the area shops yet. That was the 1st one I was recommended. So it went there.

I will probably be able to take a trip up there tomorrow or friday since I wont be working

I really appreciate all the info from you and everyone else