Curiously...all my shop manuals say that the battery on my 50 Shoebox should be positively grounded however when I got my car it was negatively grounded. It has run fine for the last five months but now it is not starting and I am having to trickle charge it often (new battery). My 49 Shoebox (been switched to a 6 volt alternator) is positively grounded but I wasn't sure if that is because it has an alternator versus a generator. I am wondering if this might be causing my problems getting the car started or is this alright? Can I switch it back without hurting anything? What do you guys suggest? Thanks in advance!
Come on guys...help a brotha out! I gotta a guy coming by to look at the car and REALLY need to get it started! ANYONE????
[ QUOTE ] Curiously...all my shop manuals say that the battery on my 50 Shoebox should be positively grounded however when I got my car it was negatively grounded. It has run fine for the last five months but now it is not starting and I am having to trickle charge it often (new battery). My 49 Shoebox (been switched to a 6 volt alternator) is positively grounded but I wasn't sure if that is because it has an alternator versus a generator. I am wondering if this might be causing my problems getting the car started or is this alright? Can I switch it back without hurting anything? What do you guys suggest? Thanks in advance! [/ QUOTE ] Sounds like someone has converted your 50 to a 12V? If so that is why it has a negitive ground. If you have a trickle charge on your battery then you have a short somewhere. Try disconnecting your negitive terminal and touching the post.. if it sparks then you have a draw on your battery requiring it to be recharged. You will have to isolate the problem by disconnecting wires until the sparking goes away (usually the problem) If its not starting i'd start with the starter circuit. Hope this helps.. Neal0o
Naw, it's still a 6 volt. What is included in the starter circuit? I know it's a dumb question but I am NOT electrically inclined at all! The battery has some power (from the charger) but I am not getting any spark at the coil... What happens when you reverse to polarity on these systems? I...first of all don't know for sure...but was thinking that if the polarity was switched (on all components) the motor would start but the generator would not recharge the battery...hence the need for trickle charging all the time. My concern is that I switch things and something expensive gets burned up...
If you had it like that for a few months, than it's ok. If it was backwards you would have fried something by now. I would just go all the way to 12v so you have a conventional system with no guessing, but that's another issue. Are you getting fuel and spark?
No voltage to the coil or no spark from it? They will work fine grounded either way but you do have to redirect the regulator if you change it. Start running the voltage back until you find where it isn't. I'm betting that the wire is shorting out as it comes through the firewall. Had that problem in a 51 Mercury 44 years ago. That cloth insulation wears out and wasn't much to begin with. Wish I had the Merc back but would sure rewire it and put on an electric fuel pump. Pete
My '49 has a single wire altenator on it (bought it from someone else with this already on it), it is negatively grounded and only has a three hole battery...I DON'T think this is 12 volt but it is definitely negatively ground. Don't get me wrong...I'm not trying to argue with anyone...I just wanna get this straight! PS - Someone mentioned a wire from the ignition to the starter....if this wire was bad, would it allow the car to turn over but not start? How do I check it out to see if this is the problem?
[ QUOTE ] Curiously...all my shop manuals say that the battery on my 50 Shoebox should be positively grounded however when I got my car it was negatively grounded. It has run fine for the last five months but now it is not starting and I am having to trickle charge it often (new battery). My 49 Shoebox (been switched to a 6 volt alternator) is positively grounded but I wasn't sure if that is because it has an alternator versus a generator. I am wondering if this might be causing my problems getting the car started or is this alright? Can I switch it back without hurting anything? What do you guys suggest? Thanks in advance! [/ QUOTE ] Most cars changed from 6-volt positive ground to 12-volt negative ground around 1953. However, the two don't necessarily have anything to do with one another, contrary to what cheaterjack said. So, unpunk01, both of your shoeboxes came from the factory with a 6-volt, positive ground system. What was done to it between then and now is what you have to figure out. In general, negative ground is better, which is why it's used universally today. If your 50 was running fine and then stopped starting, I'd try to figure out what happened. But, yes, you can change it all back without hurting anything. You will have to positive ground the generator momentarily. Good luck! --Matt
Does anyone have a schematic for these cars laid out in the original positive ground? I'm glad ya'll brought this post up. This explains why the P.O. of my shoebox couldn't get the generator to charge. I just stood out there staring at the car after I red this, and I couldn't see it in my head. I did just have my wisdom teeth pulled this afternoon, so I'm not really thinking clearly to begin with, but a picture would really help. [ QUOTE ] PS - Someone mentioned a wire from the ignition to the starter....if this wire was bad, would it allow the car to turn over but not start? How do I check it out to see if this is the problem? [/ QUOTE ] O! Unpunk01, there's not actually a wire running from the ignition switch to the starter. It goes to the starter relay. It just energizes a coil that pulls (or pushes) a pin that connects the battery wire to the starter wire. And, no. If that wire was bad the starter wouldn't turn at all. And there's nothing going from the starter to the coil if that's what you're getting at. Make sure your coil is wired appropriately according to your battery. Pos ground, neg ground.
You say it's spinning, so probably not a starter. Ok, so you have fuel for sure? - but not sure about spark? Leave everything hooked up. Pull some spark plugs and lay em down so that the casings will touch some metal... like on a fender or something. Turn motor and watch to see if your getting spark on all your plugs. If you have no spark, you might have flooded the plugs. Let them dry or use a lighter on them. (not if they are soaked with gas, lol) It may be that your points are dirty or something... could be moisture? If your not getting good spark. Try cleaning your cap and blowing it out w/air real good. Are you sure that you are getting fuel or could you possibly of sucked some water into that thing? Maybe real low on gas? Maybe your parked on hill or something?
Another possibility: check to make sure you have a voltage regulator installed before the coil, otherwise the points will wear prematurely.
There is nothing wrong with running a six volt neg. ground system. Electricity dosen't care if it goes from pos to neg or neg to pos. Just in case you want to know it is more correct to have pos ground, but it dosen't matter for your application. The first thing to do is see if you have spark to the points with the key on. Use a small screw driver and pull the points apart see if they spark. If they don't you need to clean or replace them. The next thing is to check if you have current to the coil. This also is with the key on. If you have both spark at the points and coil wire replace the coil. Test one thing at a time. Hope this helps, but if you car was running fine then it's not it most likely is not the way it is wired or if it has pos. or neg. ground.
Make sure your points are opening and closing under the distributor cap. If they are, try rubbing a piece of fine sand paper on the points.
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