on my 38 stude i can charge the battery fully, go drive it and restart it 3 or 4 times but when i get home it is dead. i put new cables and a battery in it already but just used std cables, should i have used a bigger gauge cable for the 6v system? a bud told me it may not be getting enough charge back to battery thru the reg cables? i have not checked the generator or regulator at all yet aslo i am considering moving the battery from under the seat (very unhandy) to under the hood, any pros or cons to this? thx goatboy
The cable size is/can be an issue on 6 bolt systems. However, any cable about 10 ga would be sufficient to carry the charging current (assuming you have original generator) so the cable size would not affect charging. But, if your starter is drawing excessive amps when operated, the smaller 12 volt battery cables could easily be inadequate for the starter load. You have several things to check out. First, that ALL connections, battery positive & negative cables, generator wiring, regulator wring, etc., are all clean and tight. If the ground cable is attached anywhere but to the engine block, the ground path from the engine to the chassis (or wherever the ground cable attaches) must be free of grease, paint, corrosion, etc. Are you sure the generator is charging? is the battery 'new' or just new to the car? Might have the battery load tested to be sure it is not defective. Ray
You should have the heaviest batt cables possible. 00 isn't too heavy. "Std" cables aren't anywhere near heavy enough for a 6v system. 6v systems depend on thick(er) wire/cables to flow enough amps, as the voltage(think: electrical 'push' to overcome normal/natural resistance) is half as much as "normal" 12v systems. If you don't check the reg n gen, how do you know they are putting out anything? It's the 1st thing to do after correcting the wiring/cables issues - including properly cleaning & repairing the attachment points(connections must be as close to perfectly clean as possible, from both damage/fraying & corrosion) & coat those w/a good dielectic grease, as that'll save a lot of headaches later. A bit messy, but it really stops corrosion issues. Depends on if you want it as close to orig as possible (read: survivor. Which this thing is), or a resto-mod. Eventually, battery acid fumes will get on the surrounding area(s) & corrode it . It's a maintenance issue. The other one is batterys don't like lots of heat. I'm guessing you're not using a gel-cell or other sealed battery? Glad you're saving this one. Marcus...
DO check that generator/Regulator! ...And as Ray recommends, CABLE SIZE! Should be 'voltage appropriate', especially in voltages of 'six'!
ya i figured the cables i bought were not big enough, (after the fact) as for originality im not too worried about that i can make it look great and not many will know the difference. also all the fumes from batteries cant be good for ya in the pass compartment. yes it is a new battery, just a std one, and the generator is the original one too. i will get someone to test the reg and gen soon as i dont have the knowledge for electric work too much, kinda dumb on that !!!
While you are at it, I suggest you have the stater tested/inspected too. I went through a similar experience with my '38 Buick. After getting the stater rebuilt and replacing cables with larger ga and ensuring a clean current path through all connections, it was a world of difference when starting, even with the same battery. Ray
If it starts OK after the battery is charged I don't think the wire-cable size is you problem. The stock generator is a 26 or 32 amp unit wiring doesn't need to be very large wire for those amps. At 2000 rpm check voltage at the generator and at the battery they should be close to the same.
Look at the wires coming off of the generator. That's as big as as you need to charge the battery. The big 0 or 00 cables are needed for starting only
Are you installing the battery properly for the positive ground system? Unless a PO changed, it should be grounded by the positive terminal. With the key in the on position but engine not running, what does the amp gauge do??? There is a simple test for generator output. Make a jumper wire about 4feet long with alligator clips on each end. Start the car in neutral and a just the idle speed to about 1200 rpm. Ground the field terminal of the generator with the jumper. The amp gauge should peg the needle at full charge assuming polarity is correct. This also let's you know your generator is working properly. If it doesn't peg, that indicates the Genny may need new brushes. Don't leave it grounded longer than it takes to check the gauge. If the needle pegs to full discharge, the battery is likely in polarity backwards. If thegeñy checks out and the polarity is correct then the voltage regulator may be the culprit. If the VR is the problem it may respond to a dressing of the points inside the cover.
I had charging issues with my 6V positive ground 55 Merc. The generator had been rebuilt, and a new regulator installed. A friend suggested swapping larger gauge battery cables, and switching to a gel battery. Cleaned all connections and grounds, installed the fat cables and gel battery, and now the car likely would start under water. Hot weather or multiple starts have no adverse effects.
OK, since the memory cells are shot, someone help me out here. Ply46 is right on the initial test, but somewhere in the dusty recesses of the gray matter, I remember having to polarize the generator, instead of rebuilding it. Brushes maybe, along w/smoothing the commutator using a dowel n sandpaper, & then carefully using a knife tip to lower the level of the mica 'twixt the commutator segments. Still, on a lot of gen-equipt cars, I had to often polarize the gen, maybe 2-3 times per year(it's not supposed to have to be done that often), when the miserable beasties didn't want to charge like they should've. IIRC, esp after I bought the long-sitting car. I don't remember how to do that, but before I'd have it rebuilt, check the depth(length) of the brushes, & polarize the gen. It won't hurt it if it doesn't need it - as long as it's done correctly. It's not that I don't have any of this stuff - just that I haven't worked on this stuff since the 70's. Someone fill in the missing piece? TIA. Marcus...
This should take you to wiring diagrams for both 1938 Studebaker Commanders and Presidents. Worth saving to make sure the wiring is right. https://www.studebakerparts.com/studebakerparts/store/s/html/images/38-wire.jpg It's too late, I'm too tired and it's too dark to go out to the garage and check my books to see what the proper charging rate is for that rig. I've got a late 40's motor manual that should have the specs.
Generators are SIMPLE, we're talkin' stone knives and bearskins here. First thing is to keep in mind there are basically two different types of generators. Determine what type you are using before deploying the Golden Screwdriver. "Type A" and "Type B", has to do with how the Field is grounded. When you read about polarization, or output tests, or "full fielding" etc, there are specific connections done a certain way and they are not the same, it's easy to roast the VR. So don't ask Uncle Walt (who drove a Chrysler with Type "A" gennie) how to troubleshoot a Ford (Type "B") RTFM! MoToRs Auto Repair and the shop manuals have all the tests. Next, other than voltage checks at the battery, a modern digital voltmeter will not work for testing, the generator runs full tilt, and the VR throttles it back with mechanical points. So analog voltmeter will be your friend here. Simple tests, but easy to do them wrong if going by memory. Charging systems don't like any resistance in the circuits, bad grounds, VR itself needs a solid reference to ground, not "lifted". Don't fuck with the regulator current or voltage output unless and until the grounds and connections are known to be clean and tight low resistance. Otherwise you're trying to compensate for corrosion and resistance by jacking up the output. The backing plate contains the brushes and brush holders. They can get stuck and hangup. In the old days they would pull the backing plate and install a new one, the generator doesn't need removal. Finally new brushes need to be sanded with garnet paper against a commutator so they are seated prior to startup and present a full contact patch otherwise they will arc and burn, all the current flows through these. I had installed a "professionally" rebuilt generator where this wasn't done. The brushes hissed. Not knowing any better I figured they'd wear in. Doesn't work that way, they were smoked right quick.
when your running check the voltage at the battery terminals with a meter. On my Truck its about 6.2 at idle but goes up to over 7 with you give it some gas. If it goes over 7 you know your Generator is working. Clean grounds and heavy gauge cables are the key in a 6 volt system.
well got it figured out thx guys for the help, it was the regulator, pretty easy fix once i found it, going to pick one up today thanks to NAPA they seem to find the hard stuff
Anther item that assures 6 volt system proper functioning is a body to frame or body to engine wire. This will help all accessories that are grounded through the body. Less resistance, less power draw, less power draw, ESS the Genny and regulator need to work to replace what is being used. Makes for brighter lights, and less stress on the battery. I have found that powering the brake light switch through a dedicated fused power lead is also beneficial both in terms of brighter lights as well as better charging system performance at night. Pulled the feed from the battery side of the starter solenoid s its hot all the time, and connected through an inline fuse directly to the switch. Takes the brake light load out of the general lighting circuit. You can tape off the stock feed line and abandon in place. Lable it for later reference.
Does the ammeter show a charge or discharge when the engine is running ? Try polarizing the voltage regulator, just to be sure that's not the culprit.
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