Car turns over for about 5 seconds then the battery dies. I’ve put it on the charger and tried again several times. Put charger in “start mode” and it won’t even turn over once. Had new solenoid and battery. Took battery back and got replacement but doing the same thing. Could I have another bad battery ? (Actual model is Custom - but that choice isn’t available.)
If the battery is good and charged, but will only crank the starter for a few seconds, than the main suspect is the wiring between the battery and starter. Either a bad connection (loose or corroded) or a cable corroded internally.
For a start, remove the connections and clean them. Don’t forget the battery ground connection.
Time to buy/borrow a voltmeter. A fully charged battery should be around 6.3 - 6.6 volts (I assume it’s still a 6 volt system). When cranking, check how low the voltage drops and report back to us.
Also, check the voltage drop on the small starter solenoid wire at the solenoid, Sometimes aged wire or a poor connection in that particular circuit (including the ignition switch) can cause the voltage to drop too much after some seconds of cranking.
That in turn can cause the solenoid to disengage and the starter will do nothing.
This was a problem on the old VW Beetles with 6 Volt electrical systems. In the problem cases with those we used to add a generic remote Ford starter solenoid and shave the distance in the wiring.
This is more of a question than a suggestion. In this situation would it be diagnostic to disconnect the positive cable at the battery, then use one jumper cable from the positive terminal of the battery to the terminal at the starter motor?
I, personally, would not try that. You would have no overload protection of any kind; fuse, solenoid, etc. If there were a problem in the starter, all kinds of evil things could happen.
If the battery is good, I’d be checking the starter out and the wiring as suggested. But back in the 50’s people used to just walk to work instead of trying to get their cars started in the winter cold. In fact many used to just put the cars up on blocks for the winter.
did that in the olden days, but would tap the stud, not clamp it. It should let one know if the starter motor works or not. Recalling from a 1950 era truck post was it the horn ballast resistor that when bad prevented starting?
You could measure the voltage directly at the starter motor with the key in “start”. That should be close to the same as the measurement directly at the battery posts (again with the key in “start”). No more than 1/2 volt difference I’d guess. If the voltage at the starter motor is much less than at the battery, you’ve got a problem in the wiring harness or the starter solenoid. I presume the starter solenoid is like on my Ford truck, separate from the starter motor.
If the voltage at the starter motor measures ok, not much voltage loss between the battery and the SM, but you still get this slow and intermittent cranking, I’d guess the problem is the starter motor itself. There’s some electrical contacts and brushes inside the starter motor that can corrode and wear out and cause this symptom. It might be possible and more cost-effective than buying a new one to have an auto-electric shop fix the existing one.
When ou measure at the starter motor, be sure to measure between the terminal and the SM case. If it measures low that way, see if it measures closer to normal if you measure between the SM terminal and battery negative. If so you may have a problem with the ground wire between the engine and the chassis. On a 1950, pretty much anything is possible.
Unless the electrical system has been modified, I think that a 1950 Ford is a 6 volt positive ground. Be sure you have the polarity correct with the positive terminal of the battery going to the frame of the car,
Was not a 50 Ford positive ground?
@oldtimer_11 Fords were 6 volt positive ground through the 1955 model.
You could have a second bad battery. A few years ago, my old Regal wouldn’t start. At a cemetery. On the other side of town. I had it towed to a local shop and they discovered the battery was bad. A few weeks after replacement, it went bad. A few weeks after the second replacement, that one went bad too. The 3rd replacement worked properly until my daughter wrecked the car a couple of years later. It is highly unlikely, but possible. I’d check the rest of the system before suspecting a second bad battery. OTOH, it should be easy to take the battery out and get it tested at a local parts store. Since this is a custom car, I’m sure it isn’t your daily ride and you won’t have commuting and errand problems.
I would suspect that the battery cables are too corroded to carry the current.
If you need a reference book.