The Stovebolt Site Forums The Shop Area The Electrical Bay Discharging and Sparking 1953 3100

Hi Guys (and Gals)

I am stumped. I am doing a complete frame off restoration. 1953 3100 I put in a complete new wire harness, it has a newer starter (foot start) and I had the generator rebuilt a few weeks ago (Yes I polarized it). I am using the old voltage regulator that I put a fresh coat of paint on it worked when I took the truck off the road to do the restore.

OK, when I put the battery cables on the posts I get a spark like there is a direct short and it is drawing already before anything is turned on. I am not finished with all the wiring as the head and tail lights are not wired yet but everything else is. When the motor runs (it pops right off on half a turn and runs and sounds great and I am happy to get to this point more than you know) the battery gauge discharges a little, when I rev her up it discharges a lot more almost to the end of the gauge. When I put a pull on the electrical system (I turn the parking lights on and that puts the gauge lights and speedometer lights on and I switch the inside cab light on it does the opposite I would expect, the gauge moves to the center almost to the charging or + position. That is counter intuitive. It should put more of a draw on the system and pull it more towards discharge from what I know about auto electric. It is almost like if I swapped the wires on the battery gauge backwards it would show charge and solve the problem but that is not what the wiring diagram shows and I am hesitant to try that and fry everything. I did use the small cardboard piece with the gauge rebuilt kit to insulate the battery gauge.

I am stumped. I went through the wiring diagram and checked and doubled checked 3 times my connections with the paperwork sent with the wiring harness taking endless hours to try to find a mistake. It actually was an easy job and I took one thing at a time and checked wire color and chase color if it had any. I am very confident the proper wire is on the proper connection according to the diagram they sent with the harness.

The only thing I did was retain my horn relay by pulling the horn power wire up to the fire wall and cut the horn wire and ran one side to the top of the relay (horn), power to the middle and the other side of the mid way horn wire cut to the bottom just as things were with the truck before I started the resto. That was the only thing I found that wasn’t exact to my old truck and the new wiring harness. The horn hums when I push the horn button but the horn does not blow. I bought it online eBay so I am not sure it really works. I am stumped. I disconnected all 3 horn wires and take the horn out of the equation. And no change. Does anyone (if you have read this far) have any ideas for me? Where do I go from here? I don’t want to just start buying parts and throwing them at the truck if someone else has any other ideas. Thanks John

Check the voltage at the battery posts with the engine running. It should be about 1.5 volts higher than the non-running voltage, 7.5 for a 6 volt system, 14 to 14.5 for a 12 volt. I believe you've got the wires crossed up on the ammeter. Try a swap at the back of the ammeter and see if things straighten up.
Jerry

Thanks Hotrod Lincoln, for your advice, I really didn't want to swap wires from what the factory said on the wiring diagram, but you convinced me and I did. OK so now the Battery gauge now reads positive and it does show more voltage when it is running about 7 volts but the battery was run down and I think it is most likely recharging. I didn't check it before I swapped the wires on the gauge, so I am not sure if anything had changed there. But, when I put the positive cable on the battery it still sparks and the battery gauge is pegged on discharge with the key off. So the volt meter (amp meter, battery gauge) I think pretty much they are all interchangeable and we both know what I am talking about is hot all the time and is drawing somewhere when the key is off. There were only a few things different from my truck on the addendum. If it was a foot started truck and not a key started truck, the start side of the key wire had to go to the positive side of the volt meter. Mine is a foot start. That wire runs to the positive side of the battery gauge and the starter, I am wondering if they are wrong and it has to run through the key switch so it is not hot all the time. Since my key switch is only 2 position, on and off, No start. The other thing I was wondering if the voltage regulator is calling for charge and the points are closed could there be a power draw there between the generator, starter and regulator and feeding back to the volt meter? In other words if it was calling for the battery to be charged would it be reasonable to expect some spark since the circut is completed with the points closed? I was very happy with this wire harness, the color, size and the correct wire ends were all correct and nothing really hit any snags and it was impressive and easy, but now I am wondering if their directions and schematic is wrong? I guess the way to start is to disconnect everything but the positive cable to the starter and connect the positive side of the battery and see if I get the draw and sparks when I hook it up, then one by one disconnect one wire at a time until I find the bad component. I am out of answers and this Coors light is not coming up with anything either so that was no use. I don't know, maybe take it all back apart and start over? It sounds like a big task especially since the truck has been built as I was going... motor, gauges, fuel gauge then the seat, ETC... Yikes.

Try disconnecting the wire at the generator Arm. terminal, and see if your short goes away. If so, the cutout relay points in the regulator are probably stuck together. That's a not-uncommon problem with generator/regulator charging systems, and it usually damages the regulator beyond repair. Once the points stick, there's enough damage to them that even filing or sanding the contacts doesn't guarantee it won't happen again. The good news is, if it's still charging, the generator hasn't been damaged.

Most replacement regulators are not polarity-sensitive, so positive or negative ground shouldn't be a concern. If the short is not through the regulator, just start disconnecting circuits one at a time until the short goes away. It's possible something has been connected incorrectly and it's drawing current from the battery continuously. The generator/regulator circuit is the most likely suspect.
Jerry

Yes, Thank You, when I disconnect the Gen Armature terminal the short goes away, so does that mean if I replacement the 6 volt voltage regular the short will go away and solve the problem?

Pull the cover off the regulator and see how badly the cutout relay points are burned. Usually, they weld themselves together pretty firmly, and the regulator has to be replaced. If you can separate the points, the short should go away temporarily. No guarantees that they won't stick again, however. The cutout relay is the set of points behind the Bat. terminal, and they should be open with the engine not running. The other two, the current regulator and voltage regulator, have spring-closed points that are pulled open momentarily to drop armature voltage and reclose to put the generator in full output again. This process happens several times a second to control current flow or voltage. The cutout relay is either open or closed, no cycling on or off unless the engine stops.
Jerry

The cover was on with 2 small rivets so I drilled them out to open the cover, I was going to buy a new one anyway since everything else was new so I figured what the hell... Well once again your knowledge was correct, the points behind the BATT terminal were stuck, I put my finger on them and they snapped free. The other 2 were moving fine. So if the new regulator comes in tomorrow like NAPA said it would on the afternoon truck I guess it will tell the story, stay tuned. Thanks again Jerry.

Thanks Jerry,

It was the voltage regulator. I installed a new one today and that cleared up all my problems. This was not the first time you have responded to a post I had written and helped me, it is knowledge like yours that makes this website such a good source of information for u guys that want to do it the right way. I for one want to thank all of you guys and Jerry that help us all out. It really helps!

John