48 Dodge Battery to starter trouble shooting _ any ideas

[Ed McDermott]

I have a 48 dodge custom with negative battery ground which I believe was modified from positive ground before I got the car.  

Reoccurring Problem;

After charging the battery the engine will start and run fine in the garage and with throttle open some to enhance charging.  After charging for 10 min the ammeter reads about < 5 amps charging.

Turned the car off and worked on the car for 2 hrs rewiring brake lights and park lights  turning them on and off during the process but never for long.

Tried to restart the car and just heard clicking sounds.  With a heavy jumper cable jumped the battery post to the starter terminal no noise at all?

Put the charger(15Amp charging capability) on for 10 minutes and then started the car with the charger on (still connected)__ started right up.

Shut down for 10 min with the charger removed and car restarted right up.

This has happened a number of times before and seems like the battery does not have enough capacity (550 cold cranking amps and 750 cranking amps @ 32 deg) or there is a high resistance path in the starting circuit.

The battery is 1 year old.  The starter relay/solenoid is mounted to the inside of the fender next to the battery.

Have cleaned all connections from the battery to the starter and return path.  All cables are relatively short with no evidence of corrosion.

Having the battery checked tomorrow.

I know you need to run the engine at higher rpms to adequately charge the batter after starting.  One thing I have not checked is the starter bolts to see if they are tight as they provide the ground return path, however when the battery has been charged it seems to start fine but if the battery voltage reads 6.2-6.4 volts it seem its too low to start. Baffled.

Any one experience similar or have any suggestions.

Thanks

Ed

[Sniper]

A voltage drop test will help sort things out.  Resistance measurements with an meter uses milliamps of current and one good strand of copper will make it read good.  Starting uses substantially more current, sometimes in excess of 100 amps and it needs a real good connection to work properly.

 

With our setups you need to test the cable from the battery positive to the starter housing, from the battery negative to the solenoid, test the cable from the solenoid to the starter AND test the drop across the solenoid. 

 

 

 

[JBNeal]

I recently refurbished a starter by shining up the commutator, fixing a sticky brush, and dry cleaning the innerds...it was like a new starter again...cost: 2 hrs + $0

 

additional information - starter ground performance upgrade

[Ed McDermott]

On 6/6/2021 at 6:16 PM, Sniper said:

A voltage drop test will help sort things out.  Resistance measurements with an meter uses milliamps of current and one good strand of copper will make it read good.  Starting uses substantially more current, sometimes in excess of 100 amps and it needs a real good connection to work properly.

 

With our setups you need to test the cable from the battery positive to the starter housing, from the battery negative to the solenoid, test the cable from the solenoid to the starter AND test the drop across the solenoid. 

 

 

 

Tanks for the info the video was helpful with the voltage drop values.

Battery check ok

starter solenoid checks or  from +5 to 6.2 volts with variable power supply and low ohmic  value.  replaced some wires and recleaned  some connections  and now on to voltage tests as you recommended.

Ed

[Dartgame]

My guess is your starter needs some attention, the load (amp draw) when cranking may be high due to internal resistance (lack of lube on bearings) or corrosion/dirt on the commutator and brushes. Take it out and disassemble & clean as suggested above by JB Neal. Be sure to make index marks on the main exterior components so they go back together the same way.

[maok]

Check the water level in your battery.

[vintage6t]

Make sure that your battery cables are not for a 12 volt system. A 6 volt system requires larger gauge cables to deliver proper starting current. A 00 welding cable works well.