VCCA Home Forums TECHNICAL - GENERAL Electrical - 6 volt '50 electrical... again!!

One thing about the distributor that confuses people is that it can be put in any position and still work as long as the vacuum advance hooks up okay and the grease cup is accessible. All you have to do is determine where #1 is and put all the cables in correct sequence. There is a correct position according to the manufacturer (as the JYD pointed out), but it doesn't HAVE to be that way to work. It is nice to have it correct, though.

Check the cables for corrosion (even up under the insulation of the positive) and replace if necessary. And make sure the connections are clean, tight and make good contact.

Jane sounds like she humors you pretty well, but I sure wouldn't push it any more than she likes to push the car...

Jane's a real sport... I think she hated pushing it that day because she had just gone for a 50k bike ride! The '51 got push started due to the heat in Flint 3 times as well, and she keeps coming home to me... I must be doing something right!

OK... here's where I am today. Frustrated!!

I took the battery ground off, cleaned it and the block where it attaches. I hope I'm not working against myself, switching too many things and getting different symptoms.

Today, when I turn the key on I get power to the left side of the coil. When I crank it I get power to the right side and to the points. It seems weak. When I stop cranking it all of a sudden gets stronger, and once almost fired as I stopped cranking. It seems to have plenty of power to the starter. Does this mean I'm not getting enough juice to the coil? Is it something that can be fixed at the regulator? I didn't try by-passing the ignition switch as suggested, I figure that if it starts, I'm no further ahead for the next start.

Check the electrical circuit from the starter switch to the coil.

Or better yet install the jumper from battery + post to + side of the coil. If you use an alligator clip you can take it off easily to stop engine. If that works then you have at least isolated the problem to between battery and coil. If that is the case the ignition switch is likely the problem.

So she is up to pushing cars for her "cool down" from biking?

Actually you are farther ahead by doing the jumper from battery positive to coil +. If it does start, you have a bad wire or switch in the ignition circuit. If it doesn't start you may have a problem in the starter causing it to draw too many amps. But if it doesn't start with a push, I doubt that it has anything to do with the starter.

I like to think of it as biking to warm up for pushing cars!

Okay, but don't have her working so hard on the other things that she doesn't feel up to doing other stuff for you..... You may end up having to make your own supper....

Ok... here's todays new list of symptoms.

I got it started! I ran a jumper to the positive on the coil. It seemed to not draw enough power to the starter now, and wouldn't start, but it sure sounded like it was trying to... a couple of good chugs! I then jump started it off of the '51, and it fired right up! Now the new symptoms... right when it stopped wanting to start, it was hesitating every time I stepped on the gas... still doing it. Is this because the wire going to the coil may be bad, or because the key switch is bad? If the key was bad would there not be more problems showing up? One thing I noticed is that the gas gauge reads 1/4 tank before I hooked up the coil lead, and 3/4 tank after! I'm up $25...I think I'll leave it hooked up!

I drove it around the block, and parked it back in the garage. It wouldn't restart! At least Jane doesn't have to push it... I may get dinner tonight!

Ok... I'm thinking of checking/replacing wire from the key to the coil. I don't have a spare key switch, so I'm hoping it's not that! Any other ideas?

If your key switch is bad, most likely you just need to open it up and clean the contacts. If one of the wires going to the switch or from it is loose,shorting or open, you can use a multimeter to check them out and replace if bad. Hmmm, I was thinking you had the Electrolock set up, but you don't, so I'm not sure about cleaning the switch contacts.

Good luck with it all! Rave about the dinner! (If you get any) Women do like for the vehicle you take them for a ride in to also get them home. A slight "breakdown" out in the woods is acceptable, but you need to be able to come up with a plausible explanation and get it running again without her having to push it.....

Well... I'm getting there. Here's the things I've eliminated... My neighbour came over and helped me for quite a while today. We ran a parallel wire to the wire from the coil to the ignition... No difference, so the wire is fine. We took out the key switch and and started it by holding wires together... Same thing, key switch is fine. All the while the car is starting when we put a jump to the coil. Next we went to the parts box and found two voltage regulators. One was a rusty piece of junk on the outside, and the other had "6 volt pos grnd" written on the box, but was brand new. We put that on, and the car fired right up and ran smooth! We had the firewall cover off to hold the wires for the key together, and when we went to put it back on there was shorting and sparks on the speedo cable. I guess that's the positive ground biting us? We took it off and put the old one back on. Do I need a new one, or is it adjustable?

Oh... and we took a volt meter and did some measuring on both cars. I'm not sure how it works, but here's some weird numbers. Both batteries put out around 6 volts with the car off. On the positive side of the coil the '51 is still at 5.8 volts, while the '50 is down to 3.9 volts So there's still a huge problem somewhere!

The coil on the 50 probably is shorted in the primary winding.

All Chevrolets are negative ground so you should use a negative ground voltage regulator. Since you switched from a negative ground voltage regulator to a positve ground regulator and back again, don't forget to re-polarize your generator.




To be safe, when working on wiring always disconnect the battery first.

Mack... I'm short on volts before the coil. Also the coil seems to work when hooked directly to the battery. We have been unhooking the battery to do all the work, for safety sake... eventually you have to hook things back up and try it though... The shorting on the speedo wire happened with the car running...

So does this sound like a voltage regulator problem? Or am I just knocking off another thing not to look at? If the generator needs repolarizing, how will the car behave? We ran it back into the garage...

If the generator needs polarizing, the amp meter will not show a charge when the car is running. However, ANYTIME the generator is removed or the voltage regulator is changed the generator needs to be re-polarized....especially if you go from negative ground to positive ground and then back again.

Positive ground didn't strike you as strange, eh? I think your regulator is probably okay, but you can check it by testing the voltage on the battery with the engine running. It should be a bit over 6 volts.

Anyway, I think you need to remove the battery cables and test them for continuity. I think you are losing some through the positive cable, but it could be the negative one as well.

Then again, you may be losing voltage between the battery cable connection and the wire going to the starter switch. Did you check the voltage at the switch? How about at the starter end of the wire going to the switch?

Did you disconnect the wire from the + side of the coil and check the voltage without it hooked up?

Battery cable to starter to switch to coil seems to be the problem area. It would seem that there is a bad wire or connection in there somewhere.

Positive ground regulator was ify because it came out of a box in Dad's barn, and I had no idea if the box was labeled correctly. Thought it may be wrong because we never had any cars with pos grounds.

I have to work the next couple days, so I'll get back to it later.

with sparking at the speedometer cable i would check the ground wire between the frame and the engine. i had this happen to me on an 84 gmc the ground strap was off and the engine grounded thru the speedometer cable and set fire to the plastic coating on the cable. what a suprise that was.

Okay... I've kind of got the car back to where it was 3 weeks ago, without having really done anything! I checked the cables, and am fairly certain it's not them. I had the battery on the charger overnight, and come up with 6.13 volts off of the posts, and the same at the starter... so the positive is Okay. Yesterday we got the car started by bypassing the switch, and starting the car with the coil wired right to the battery. I had the key right out and cleaned it up, but it was fine. After I put it all back in, and after having messed with the regulator, I am now getting a good voltage reading at the coil, but the starter is working too hard again! It still starts, but cranks slow. The car hasn't charged itself in some time now, and has had poor lighting for 10 years. I fixed the turn signals, and disconnected the head lights, but no signs of a bad ground. The lights are now working great, but that may be because the battery is freshly charged. I've always assumed it's a bad ground somewhere, but may need to look at polarizing the generator first. How do I do that? And where are the reverse lights supposed to be plugged in? They stay on when the car is off and left in reverse!

Oh... and after it ran for 15 minutes, and I took it around the block with the lights on, I got a reading of 5.91 volts at the battery... again, it's not charging...

To polarize the generator: touch a jumper lead from the battery terminal of the regulator to the generator terminal and remove immediately.

With the generator charging you should have about 7.5 volts at the battery. If you are getting some increase but not enough, there are some adjustments on the regulator to bring it up and/or the points in the regulator need to be cleaned. If there is no increase you need to troubleshoot the system to find out if it is the generator or the regulator. Go here to test charging system:

http://chevy.oldcarmanualproject.com/electrical/4956MAE/4956MAE06.html

Go here to check your starter system: http://chevy.oldcarmanualproject.com/electrical/4956MAE/4956MAE05.html

I'm not sure where the back up lights connect, but they should only come on when the ignition switch is on.

I had a really good day today!!! But now I have a new symptom!

I hooked the key back up, straightened out some wiring behind the dash an cleaned some contacts. I repolarized the generator... and for the first time in years I got a solid positive on the ammeter! It didn't go far right to positive, but 3/4s of the way. I'm assuming this is because I had the battery on the charger?

New symptom... I'm getting good solid spark from all cylinders but #6! I changed the wire, the plug, the cap, and the rotor but still get a light spark. I'm also getting a carbon build up on the plugs, and there's black looking soot and moisture on the garage floor at the tailpipe. Is this sign of a bad valve? It sounds like there's a miss, but I can't tell if it's from the plug not firing, or if the plug doesn't fire right because of a valve... if that's possible!

Thanks again for the help... you guys have been great with the ideas and solutions! I'm really hoping to get this thing into one tour this year, and we only have two left!

Good to hear that the original problem seems cured! Turn your lights and accessories on and see where your ammeter reads. You have weak spark holding the cable near the block? Or hooking up the plug and holding it against the block?

The soot sounds more like excess gas burning. It may just be from all the problems you've had over the past week or so with it not starting or running right. Take it out on the road and up to speed for a while; might take care of the #6 problem, too.

You could do a compression test to check the valves.

With the lights on it goes back to about neutral. I still think there's a short somewhere... I'm getting a weak spark holding the wire to the block, and touching a screwdriver to the end of the plug and the block. The other cylinders really jump... the front one is really weak. Not the wire, plug, cap, rotor. Is it possible valve, or timing? Can timing make 5 plugs fire right, and one be off? I wondered if an exhaust valve is stuck...

It may just be the contacts in the regulator need cleaned and adjusted, but if the battery is charged up and the lights on, just above center seems about right. The site I gave you has some values for volts and amps you can check for and tells you how to make adjustments if needed.

Could just be where you are touching the cable or spark plug to the block. Perhaps a bit of paint or rust not making a good ground? There is nothing I can think of that you haven't changed that would cause just one cylinder wire to spark weak. Did you clean and gap the plugs?

Take it for a drive and see how it acts when you get back.

Do you have a standard or automatic transmission?

If you don't have one, invest in a service manual for your Dad's cars, they are $25 or so. That manual has always been my bible for my '51'.