Troubleshooting Electrical Problem

H

hperrong

Junior Member
So I got my 1935 Ford a few days ago. I took it out for a ride last night but I forgot to turn the on off switch to off. Now, the car will not start. Not even the dimmest light.
The fuse looks to be OK and I recharged the battery... 6.8 volts or so when disconnected from the car.
When connected, the voltage across the terminals dips to about .5 volts.
Any idea how to troubleshoot or if I might have burned something out? I really need to get this fixed!
 
Most lilkely your coil has burned-out from leaving the switch on. Not sure if this also effects the points but I'm sure someone will confirm.
 
A couple of things. How did the car stop without turning the ignition switch to "OFF" ? If it stalled you have other problems.
If the battery measures 6.8V off the car and only 0.5V on the car, the battery is bad. Disconnect the battery cables and read the battery voltage again, if back to 6.5V then take the battery to a auto parts store they can check the battery condition under load.
It is possible the coil is damaged but also possible it is OK. Get the battery checked first.
 
I believe the coil is fine. Across the primary side it is about 1 ohm and across the secondary side it is 7000 ohm.
 
I did turn the ignition switch off, but then back on without starting the engine. I wanted to check the headlights but got ******* and forgot.
I will check the battery under load. It is brand new, however.
I did disconnect and it is still about 6.8 V.
Thanks for all your help so far. Will keep troubleshooting and will come back with an update.
 
It appears your car coil has been changed to a more modern style.
An original 35, the headlights will operate with the engine and the ignition switch in the "OFF" position.
 
I'm confused with some of the answers, are you saying the battery checks fine disconnected but when connected the system pulls it down to .5 volts? And what does a coil have to do with a low battery? Could well have a bad coil, but I didn't see anything in the original post to indicate that other than it is a possibility if the switch was on and the points were closed.

Need to trouble shoot this step by step, first need to confirm the battery is good (new or old is not the issue, still needs to be checked). If the battery is good, need to determine what is putting that much load on the battery when it is connected to the system. Are you sure the battery is connected properly, (+) to ground and (-) to the electrical system (assuming 6V (+) ground)? After those issues are resolved, then if the battery is working properly in the system and the engine will crank over, start checking things like a bad coil.
 
OK.
I took it to my local auto parts store and was told that the battery voltage is OK but it has no charge (no amps). I was advised to keep it on the charger under the "trickle charge" for about 12 hours.

So it is looking like the battery is still dead. The coil does appear to be newer, but I can not account for the voltage drop either. This drop occurs when the terminals are connected, regardless of whether the switch is on or off. Unless this is a result of the low charge, I have no idea why the voltage bounces back when the battery is disconnected.

Also, if the coil was bad, how would you go about troubleshooting that? The odd part is that the horn and lights do not work with the switch on or off and the engine does not even attempt to crank.
 
Not odd if the battery is dead (very low charge under load). Battery voltage doesn't mean much except under load, that is the reason it needed to be tested at a shop with the proper test equipment. A good battery should take a charge is a fairly short period of time, so if it is not charging looks like you will need a new one.
 
I'm with the guy at the parts store. disconnect the battery from the car. put it on trickle charge for 12 hours. I would try this before buying a new battery. what does this 35 look like? slow down enjoy !!good luck don
 
Wow. Thanks for all your help.
I left it to charge overnight. Now I have very dim headlights. So at least my electrical system is not fried.

When trying to start, the solenoid gives a click but does not crank the starter motor. Additionally, the horn gives a little popping sound each time it is pressed but it does not sound.

I think this is a sign of a bad battery. Thoughts?

I am going to buy the optima red top 6v battery. Seems like a very good one. Any experiences or reviews? Thanks.
 
You can fit an Optima in the same location as the original battery but you will need to make a battery bracket to hold the battery about 2" lower than the original battery for clearance to the cover and toward the front so the battery cables connect to the battery. The new battery bracket can use the original holes for the original battery hold downs for mounting.
Before scraping the original battery put it on your charger for a longer period or use a larger (Amperage) battery charger for another 12 hrs. It seems like your battery is still not fully charged.
 
A battery should charge in an hour or two at most. It might be possible to get the battery to charge by leaving it on the charger for a longer period of time, but it is still a defective battery and won't hold a charge for any length of time. You can have a low (but in good working condition) battery in a car, jump the car to get it started and have the battery charged back up in a few miles of driving. So it would charge up is say 15 min.
 
Hi there, If a 6 volt battery is showing good voltage of say 6 volts to 6.3 volts it then should be load tested on a proper battery load testing unit. This tester can place a heavy load on a battery just like when a starter motor is cranking. This load can be varied on the tester at anywhere between 50 to 500 amps or so whilst a voltage reading is shown also on the tester. Some batteries get a bad connection inside on the grid connections or internal terminal connections which break down under heavy load. This may be the case with your battery is my guess and it is a common type of battery fault. The optima battery is a good choice for your car. I have fitted many of them to all types of vehicles and have had very little problems. They will generally last at least 8 years or more if looked after. I have one in my 1970 ford falcon V8 that is 13 years old. Good luck, Regards, Kevin.
 
I'm sure you've thought of this but if not, it's worth a try.Turn on your lights then,use a heavy gauge wire between the ground post of the battery(not the cable)and ground it to the block or frame.Now watch the lights.If they get brighter,you have a bad ground.
 
I actually believe the battery location was re-located. It is under the hood. The ground is positive, and uses a brand new, nice, thick wire to the chassis. I tried it with another wire, however, and it made no difference.

I will try charging the battery again... now I am wondering perhaps it had a low charge to begin with and my dynamo is not working.

By the way, what is the best and safest way to jump this car?
 
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