6 Volt System w/an 8 Volt Battery-Issues

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   Hi guys-Trying to trouble shoot my system.  This is a Delco neg ground system on a 1940 Chev pickup.I recently put in an 8 volt battery and even when I had a 6 volt battery, I do not think it charged.
When I turn on the lights, the ammeter goes negative like you would expect.
I ran a test where I took direct power from the battery and applied it to the generator armature...that caused the generator to turn like it should and it turned in the correct direction.
Anyway...saw on line if you disconnect the field wire from the regulator and connect it to a jumper wire directly to the battery, if the generator is good, it will go on full charge and pull down the engine slightly once the connection is made.   And this means the rest of your system is good and the regulator is bad (or needs to be tweaked to work at 8 volts).

Mine appeared to do that but when I look at the ammeter gauge it is pegged full negative.

What the heck?   Any thoughts...

Edited by nowaktj - 28 Sep 2018 at 7:01pm

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nowaktj Members Profile Send Private Message Find Members Posts Add to Buddy List Orange Level Joined: 13 Dec 2009 Location: Elk River, MN Points: 725	Post Options Post Reply Quote nowaktj Report Post Thanks(0) Quote Reply Topic: 6 Volt System w/an 8 Volt Battery-Issues Posted: 28 Sep 2018 at 4:45pm
	Hi guys-Trying to trouble shoot my system. This is a Delco neg ground system on a 1940 Chev pickup. I recently put in an 8 volt battery and even when I had a 6 volt battery, I do not think it charged. When I turn on the lights, the ammeter goes negative like you would expect. I ran a test where I took direct power from the battery and applied it to the generator armature...that caused the generator to turn like it should and it turned in the correct direction. Anyway...saw on line if you disconnect the field wire from the regulator and connect it to a jumper wire directly to the battery, if the generator is good, it will go on full charge and pull down the engine slightly once the connection is made. And this means the rest of your system is good and the regulator is bad (or needs to be tweaked to work at 8 volts). Mine appeared to do that but when I look at the ammeter gauge it is pegged full negative. What the heck? Any thoughts... Edited by nowaktj - 28 Sep 2018 at 7:01pm
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Jim.ME Members Profile Send Private Message Find Members Posts Add to Buddy List Orange Level Joined: 19 Nov 2016 Location: Maine Points: 952	Post Options Post Reply Quote Jim.ME Report Post Thanks(0) Quote Reply Posted: 28 Sep 2018 at 5:30pm
	What is this system on? Is it a Delco generator? If it is a Delco, it is a Type A, externally grounded generator. You have to ground the field terminal to test for full generator output, not apply power to it. Check the ground of the regulator, it must be well grounded as it is the ground point for the generator fields. Type B system generators (Autolite/Ford for example) are internally grounded. Those you apply battery voltage to the field terminal to test for full output.

Jim.ME Members Profile Send Private Message Find Members Posts Add to Buddy List Orange Level Joined: 19 Nov 2016 Location: Maine Points: 952	Post Options Post Reply Quote Jim.ME Report Post Thanks(0) Quote Reply Posted: 29 Sep 2018 at 6:24am
	Delco Type A info I posted applies to your Chevy. Disconnect the wire from the field terminal of the regulator and ground that wire to check for full output. I usually ground the generator field terminal with a jumper to eliminate any question of the vehicle field wire condition. Check condition of the regulator contact points and its ground. There is usually at least one resistor in the base of the regulator that can fail. You can see it if you remove and turn the regulator over. If you clean the points you should use commutator paper or another non-conductive paper, the same as cleaning a commutator. Dust and residue from most emery cloth is conductive and can cause issues. If charging and wired correctly your ammeter should go full charge not full negative. I have attached a drawing I found on line of the way to polarize the Type "A" and Type "B" systems.

DougS Members Profile Send Private Message Find Members Posts Add to Buddy List Orange Level Joined: 03 Nov 2011 Location: Iowa Points: 2490	Post Options Post Reply Quote DougS Report Post Thanks(0) Quote Reply Posted: 29 Sep 2018 at 6:34am
	I hope you're running good old-fashioned heavy battery cables. 8 volts is a bit hard on lights and such. With heavy battery cables and clean connections, 6 volts should be fine. If the original cables were replaced with lighter 12 volt cables you're going to continue to pull hair, no matter. Finding the correct setting for your generator will always be a pain.

DrAllis Members Profile Send Private Message Find Members Posts Add to Buddy List Orange Level Access Joined: 12 Sep 2009 Points: 20534	Post Options Post Reply Quote DrAllis Report Post Thanks(0) Quote Reply Posted: 29 Sep 2018 at 7:05am
	If the generator is a third brush design (like a WC-WD-WD45) you can increase its output by moving the adjustable brush closer to the fixed brush. Loosen screw on the back wall of the gen and slide the brush up or down as needed and tighten screw,

Steve in NJ Members Profile Send Private Message Find Members Posts Add to Buddy List Orange Level Access Joined: 12 Sep 2009 Location: Andover, NJ Points: 11823	Post Options Post Reply Quote Steve in NJ Report Post Thanks(0) Quote Reply Posted: 29 Sep 2018 at 7:33am
	An 8V Battery is a bandaide for a 6V system that isn't working correctly or has a component no working correctly. "Motoring" a Generator doesn't always mean the unit is good. Its output may not be good. It can still "motor" when current is applied. Grounds are super important in 6V systems, so make sure the VR is grounded correctly, connections are good, cables proper (1 ga. or larger) and have the Generator load tested at a reliable rebuilder to make sure the unit is actually working properly. Draw test the Battery to make sure its not your power source that's the problem. A very overlooked area. Doesn't mean a thing if the Battery is new. Its new to you, but could be bad. If its the original wiring that's in the truck, inspect the main circuitry for breaks or fraiding. If it uses a starter button, check for corrosion or high resistance around the starter switch terminals. Another hidden problem with 30's & 40's Automobiles... HTH Steve@B&B
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Gerald J. Members Profile Send Private Message Find Members Posts Add to Buddy List Orange Level Joined: 12 Sep 2009 Location: Hamilton Co, IA Points: 5636	Post Options Post Reply Quote Gerald J. Report Post Thanks(0) Quote Reply Posted: 29 Sep 2018 at 10:29am
	My experience beginning with a 6 volt 1964 Ford car is that the battery posts need to be cleaned twice a year and the connectors too. Going to an 8 volt battery is a cobble to lessen the effects of corroded battery posts and connectors, but it is hard on lamps and won't work with a generator with a voltage regulator. The 8 volt battery only gets charged with a 3 brush generator with only a cutout and no regulator. Get a 6 volt battery that hasn't set on the store shelf without being charged for more than a month, clean the posts and the connectors and everything should work fine providing there are no wiring problems. Basically a 6 volt system isn't tolerant of bad connections anywhere. Gerald J.