Battery keeps going dead

[Tyler92]

I have a 1952 dodge truck with a flat head six and the keeps battery keeps going dead it’s brand new 6volt and reading 6.9 on a tester I’m new to this but I really want to keep the truck as original as possible thanks 

[JBNeal]

If your wiring harness is original, I suspect its insulation has failed and a circuit is grounding...

[Merle Coggins]

Could also be a faulty voltage regulator that's not disconnecting the circuit breaker contacts. This will drain a battery through the generator when not running.

[Plymouthy Adams]

The best way to find a battery drain is to place a test light between the battery and the cable....if the lamp lights, and all things are supposedly off....you have a short...open each circuit feed from the starter, solenoid or ammeter and ignition switch till the light extinguishes...take note that if you have an door activated compartment light to test and disconnect it first to prevent false reads.  Keep in mind also you may have more than one short....place a piece of tape denoting the connection point and let dangle till the light is out...when the last lifted wire extinguishes lamp....go back and add each disconnected wire making sure the lamp stays off....this will tell in this is the  only fault or if multiple...a buzzer in line will do the same thing if you need an audible alert...you can use both if you wish....many modern digital VOMs have built in audible alerts in the OHM test position.  Once the faulty circuit is found your VOM is excellent for zeroing in on the cause...many are simple frayed wires, some are critter induced and sometimes the critter is you pinching a wire when working in and around wiring harness mounting accessories or components.

[kencombs]

15 minutes ago, Plymouthy Adams said:

The best way to find a battery drain is to place a test light between the battery and the cable....if the lamp lights, and all things are supposedly off....you have a short...open each circuit feed from the starter, solenoid or ammeter and ignition switch till the light extinguishes...take note that if you have an door activated compartment light to test and disconnect it first to prevent false reads.  Keep in mind also you may have more than one short....place a piece of tape denoting the connection point and let dangle till the light is out...when the last lifted wire extinguishes lamp....go back and add each disconnected wire making sure the lamp stays off....this will tell in this is the  only fault or if multiple...a buzzer in line will do the same thing if you need an audible alert...you can use both if you wish....many modern digital VOMs have built in audible alerts in the OHM test position.  Once the faulty circuit is found your VOM is excellent for zeroing in on the cause...many are simple frayed wires, some are critter induced and sometimes the critter is you pinching a wire when working in and around wiring harness mounting accessories or components.

Good advice.  Finding the drain requires a good plan and step by step isolation.  That said, the most common causes I've encountered have been, the cutout relay in the voltage regulator, sticking brake light switch and similar issues with an underhood trouble light, trunk light, or courtesy lights inside the car.  Most of those are obvious if you're working on the car inside or in the dark.  But, outside or in daylight, easy to overlook.

 

IMO, a short is unlikely as a true short to ground will result in blown fuses or crispy/smoky wires rather quickly.

 

Not knowing if the wiring and accessories in your vehicle are original and unmodified makes it impossible to provide more detail.

[Tyler92]

Thanks for the advice I’ll try it this weekend as long as the weather will let me 

[milo9rat]

It's not really a short but just a load drawing on the battery and discharging it... If it's positive ground put the test light between the positive cable and positive on the battery.. If negative ground do the same with the negative cable and negative post.. I agree with the rest of Plymouthy Adams...

[nc plumber]

I once came across a stuck horn relay that was draining the battery. Someone had unhooked the horn so it wouldn't be blowing all the time, but failed to disconnect the power feeding the relay. 

[Brent B3B]

On ‎10‎/‎24‎/‎2019 at 5:14 AM, Merle Coggins said:

Could also be a faulty voltage regulator that's not disconnecting the circuit breaker contacts. This will drain a battery through the generator when not running.

I think you fixed mine Merle at BTT50's last year!

 

went thru a few batteries because my regulator was over charging and "cooking" them. Merle busted out the meter and got me back on track... Thanks again Merle!!