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I'm having difficulties troubleshooting an electrical problem in my 1950 Standard Eight.

Some background: I've recently replaced the generator (rebuilt) and voltage regulator (brand new aftermarket supplier). A few years ago I had the car completely rewired with a setup from Rhode Island Wiring. My 6-volt battery is just a few months old and holds a good charge. To the best of my knowledge all wires and cables are the proper gauge and have corrosion-free terminals. Last autumn I replaced the distributor and had an electronic ignition installed. The radio and blower motor seem to work reasonably well. I replaced the headlight switch a couple of years ago, along with the hi/lo beam pedal switch.

Most of the time the electrical system runs well. There seems to be enough electrical power to run things just fine. HOWEVER... on some occasions when I start the car at night, and turn the headlights on, the needle on the charge/discharge meter on the dash swings way over to the left--discharge--side. It goes so far over to the left that it almost seems to peg out. The needle stays far to the left regardless of engine speed. If I rev the engine or let her idle the needle barely moves.

Sometimes I can 'correct' this by turning the headlights on & off a few times. Other times the only solution is to hope like hell I make it home before the battery goes. Sometimes it never happens at all. So far the pattern seems to be that if it doesn't happen right when I turn on the headlights then it's not going to happen during this drive. In other words, it hasn't happened during the middle of a drive.

Interestingly, when the needle makes its swing the lights don't seem to become noticeably dim nor can I detect a reduction in engine power. Of course, when it happens I immediately turn off accessories like the radio and blower, so I can't say for certain how the apparent power loss affects those units.

I'm wondering if the problem lies in the generator, the headlight switch, the ammeter or someplace else. I'm terrible fixing electrical stuff but I have a pretty good mechanic. Sadly, he admits he's not that good with electrical stuff, either.

Any ideas or suggestions on pinpointing the solution to my problem would be greatly appreciated!

All the best,

Mark

I'd do a couple of things. First would be verify generator belt is proper size for the pulley, tensioned properly and not glazed or slick. Increased current draw puts a load on the generator and if something is slipping, generator maybe not turning fast enough to keep up with demand. Since it doesn't seem to return to normal with items turned off, probably not the reason but worth checking anyway. Another thing worth checking is make sure the ground wire between generator and fender tie point and then on to regulator is in place and good connections.

Since the lights do not dim, or turning things off doesn't help, would verify proper operation of the ammeter. It could be dirty or have a piece of lint inside and when deflected on initial surge maybe not returning to proper spot reliably. This could be done by installing a second inexpensive aftermarket ammeter in series with the original so you can compare the readings. This can be a temporary thing although several have installed and hidden one just for the verification purpose. If the second meter differs considerably then look to the original and if they match, then time for an electrical shop with proper diagnostic tools. Even though things replaced, you still could have an intermittent bad generator or regulator or connection.

If belt is OK and you'd rather not mess with ammeter, then you could just take the car to a shop and have a load test done. Many places do them for low or even no cost if you buy another service. They have monitoring equipment that could verify with all the accessories on, generator is putting out the proper 7.4 volts and 35-40 amps. You could have them turn on all accessory combinations you normally use one at a time and if any is pulling excess it should show up right away.

Thanks for your response, Howard.

Just to be clear, regarding my "Case of the Left-Leaning Needle:" the ammeter needle does move a bit to the left when I turn on the running lights and then moves hard to the left when I press headlight switch the second time to turn on the headlights. The needle stays in position irrespective of engine speed.

I'm reasonably certain the belt is the correct size, that it is tensioned properly, and that it is not slipping in any way.

I'm curious about your statement about the ground. You wrote, "Another thing worth checking is make sure the ground wire between generator and fender tie point and then on to regulator is in place and good connections."

Can you please expand on this? Where is the fender tie point located on a 1950 Standard Eight?

The wires from my generator disappear into a harness that's basically a wrapping of electrical tape. The harness snuggles against the inside of the driver's side fender, running above the wheel well. It heads aft, toward the firewall, and ends close by the voltage regulator. At that point many wires emerge and go in a bunch of directions.

Where is the ground point (fender tie point) located?

Thanks much,

Mark

You should have 3 wires on the generator. The ground is a smaller probably black wire and goes to a screw on the case rather than the terminals with fastening nuts. From the generator it goes to the L fender or radiator support where the 3 terminal headlight junction block is fastened. Ground goes to one of the mounting screws holding terminal strip in place and may have several others on the same screw--although some could be attached to the other mounting screw. One of those, again probably black will go back to the regulator and either fasten to a small screw labeled ground or to one of the regulator mounting screws. Ideally that wire to regulator will be continuous or at least on the same screw as the one from generator.

The regulator needs to be at the same reference to the generator and not be getting it's ground through a lot of engine mounts, bolts, sheetmetal and cast iron.

Dear CaptainBristol:

Let's try a few basic things:

What happens when the motor is not running and you turn on the lights? If things are normal then you have a regulator problem.

If not, then disconnect one head light. Still pegged? Disconnect the other. Still pegged? You have an intermittent short circuit.

You can confirm be disconnecting the voltage regulator battery wire with the motor idling.

Next a word of advice on your gauges. The Packard manual advises against trying to use the ammeter as an indication of discharge rate. Thus I would follow Howards advice, buy an accessory ammeter, and hook it up in series with the main harness takeoff at the starter. Then see what the readings are when you turn on the headlights.

Off the top of my head I would suspect a faulty dimmer switch on the floorboard, or a short at the switch. Who knows, maybe the parking lights are going out when you turn on the headlights due to a short circuit.

A short in the harness can hopefully be isolated by wiggling along the harness and disconnecting wire at the switch.

Hope this helps.

Captain

I recently sold a 1950 Eight that I had for a long time and drove many miles. I had consistent charging problems and put in about 6 voltage regulators. I paid people several times to go through the charging system. The last mechanic ("called Speedy" so you know he''s good) immediately noticed that there was no ground strap betweens the engine and the frame. Problem solved after 13 years and at least $2,000

Regards

John Harley

noticed that there was no ground strap betweens the engine and the frame.

That's a good point. Packard apparently didn't use separate straps till 55 -- that ground wire I described above was their version of it along with several ordinary metal to metal contacts. It is a small wire so it certainly wouldn't hurt to pick a regular sized bonding or ground strap up at the parts store and go from a good solid connection on block. Not sure if it needs to go to the frame though won't hurt--more the firewall or body where all the items needing a good ground are already going. Packard installed theirs from rear of engine directly to a nearby screw on firewall--about a 6" or 8" length.

Quote:

CaptainBristol - You are getting great advice from the above posts, but I think it should be pointed out that it is normal for the parking light to go out when the headlights are turned on. This is unlike more modern cars where the parking lights stay on with the headlights.

(o[]o)

And I also wonder about a short as being an issue. Unless it's been removed or wired incorrectly, there is a self resetting circuit breaker on the headlight switch. If anything shorted, the lights should go off, cycle back on after a few seconds then go off again.

That ground strap story is interesting.

Usually Packard put the chassis ground strap on the transmission cross member. However, if the battery cable was not going to the engine then that would create big problems.

The usual method to test this problem is checking the voltage between battery ground and the body, and battery ground and the motor with accessories turned on the the motor on fast idle. A ground problem would show up as more than .4 volts with 0 - .2 volts ideal.