Totally dead after running for an hour

Rust Merchant

Rust Merchant

Member
OK guys, I replaced the starter switch and my 29 Sport Coupe fired right up. Car ran beautifully for an hour in my garage while i adjusted the carb per "Model A Basics" specs. Running better than ever. I tested the lights and turn signals while it was running, all worked perfectly. I grabbed my wife for a victory ride around the block, jumped in the car, turned on the lights.............the car died immediately. Totally dead. Will not crank. After about 20 minutes, the lights came on all by their self. Still dead when trying to crank. I disconnected the Neg cable and came in to ask the experts where to start. Obviously I have a short somewhere. Wiring looks original and there are several "amateur spices". My thoughts are to buy a new wiring harness. Any advice would be appreciated.

Dwight
 
You will need either a test light or voltmeter and test where you have current and where you do not. Is you rgenerator charging when runnning? If not, then a bad /intermittent battery terminal connection would do what you describe. Test first, then replace parts, and not the other way around.
 
have batt or generator tested, a battery that is weak will go dead while the engine is running if the generator is not working and kill engine, a battery will build up a little juice while setting but will go dead again if the motor is running with out being charged
 
Do a search on my previous posts about trouble shooting electrical. I would bet your problem is in the large leads + and - near the battery or the ground connections to the frame and motor. You may also have a bad cable between the battery and the starter.
 
Make sure your ground is good. You can do a quick check with a jumper cable from your pos. terminal to the trans. Hook it up and see if she turns over.
 
Don't run around guessing like a chicken with his head cut off, grab a test light & poke around & it will tell you where the problem is. Then you decide what the fix is. It's NOT rocket science. Listen to advice that makes sense to you or sooner or later somebody will suggest a cylinder leakdown test or "it's a bad ground at the u-joint splines"!! or no tellin' what??? Bill W.
 
Sounds like a poor battery connection and/or a short in the headlights if turning them on killed everything. The fact that they came back on after 20 minutes would have me checking the battery posts first, then the other end of each cable. The lead posts need to be shiney clean and tight.

You might want to disconnect the light/horn wire from the cutout, then take the car for a drive to make sure the generator and everything else is working ok.
 
Also, too add to Bill's and others...you could have run the battery down for
your 1 hour testing. Load test the battery, if low, charge it.
 
turned on the lights.............the car died immediately. Totally dead. Will not crank. After about 20 minutes said:
Turn off the lights (switch is on the steering wheel). Charge the battery. Start making your electrical checks. Do check the previous posts about trouble shooting electrical problems as 'jmeckel' suggested.

The car was running. Try to locate the problem without making numerous changes like replacing the wiring loom or other electrical components.

Have fun - think of it as a challenge, Let us know how you make out. Bill
Click to expand...
 
You asked where to start. Here is where. Take a volt meter and measure the voltage at the battery post. Not on the clamp, but on the 2 posts. Scrape the top of the post for a really good connection. You should have around 6.2 volts. If not charge the battery for an hour or so for further testing. If you have a little over 6 volt on the battery post next check voltage at the post on the starter and engine block (make sure you have clean metal where where your test leads touch) . You need the 6.2v here also. If not check and clean and make sure both cable at the battery posts and at the other end of each cable. When you have proper voltage at the starter post to engine it should crank. If battery was low and you charged it and now have 6+ volts should crank.
Make these checks and post here and we can go from here.
 
Thanks for the replies everyone! The battery is brand new; terminals are too. I will go through all of the suggestions and trace down the problem. Ammeter was reading fine while the car was running. I tested the Battery after posting this and it tested good.
Sounds like removing the power to the lights would be a good idea. Some of the wires running to them look "questionable."
 
Agree with Phil as a starting point. To add to that make sure your individual battery cells are at the proper level. As bill w said to much running around like a chicken with a head in its *** is not productive. If what phil says to do checks out next i would start it and keep the headlights off. Put the voltmeter across the battery posts and with an elevated idle the reading should be higher than 6.2 - 6.3 volts. Please do these things and report back
 
Ok, did not know you had been melting stuff. I would put a fuse or circuit breaker in the wire that comes off the battery cable at the starter post. This will save further melt down problems. Remove and separate the three wires at the cutout on the generator. This will isolate power to the light switch and horn. The horn has power at all times and is a common spot for a short. The car should start and runs all lights and horn will be in op. if it will not crank and run now the short will be in the wiring in the junction box and dash. This will give you the area to locate the shorting working. Keep use posted.
 
Melted battery terminals??? Is it possible the battery has an internal poor connection?

Either way, it certainly sounds like a poor connection.
 
Phil said:
Ok, did not know you had been melting stuff. I would put a fuse or circuit breaker in the wire that comes off the battery cable at the starter post. This will save further melt down problems. Remove and separate the three wires at the cutout on the generator. This will isolate power to the light switch and horn. The horn has power at all times and is a common spot for a short. The car should start and runs all lights and horn will be in op. if it will not crank and run now the short will be in the wiring in the junction box and dash. This will give you the area to locate the shorting working. Keep use posted.
Click to expand...

He is not melting anything now that was a previous thread and has been repaired due to a bad starter switch. He as since replaced the cables and battery along with the switch. good advice as you mentioned on your first post as a starting point
 
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Ok I guess there too many cooks in the kitchen. I will bow out. The man has a problem with his car. He wanted help in knowing where to look. Ever one was telling him to get a meter or light and test till he found it. Just trying to walk him through some steps. Sorry.
 
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