Q: Dead truck battery every time it's left off for a few hours.

asked by on

My truck keeps completely dying after it's left off for a few hours, dead to the point where my key fob will not even unlock it. My battery has been tested at two different stores and they both say it's good. The first store told me I had a bad alternator and after replacing it, I'm still having the same issue. Should I replace my battery anyways and see what happens since it's still covered under warranty? Or should I get a test light and try to find a power draw coming from somewhere in the vehicle? If so, how do I actually go about doing that?

My car has 216000 miles.
My car has an automatic transmission.

If the battery is new and charging system output has been measured and is within specifications, the only reason a battery will discharge is if the car sits for a long period of time (batteries will self-discharge even if not used) or if there are parasitic (excess) loads on any of the car’s electrical circuits. If there is excess current flow that is slowly draining the battery, a Mechanic would use an ammeter to test all of the various circuits until the faulty circuit is found. Then that circuit is traced to find the fault and repair it. If you want these steps performed by a certified Mechanic, dispatched by YourMechanic right to your location, please request an electrical diagnostic and the responding certified mechanic will get this resolved for you. If you have further questions or concerns, do not hesitate to re-contact YourMechanic as we are always here to help you.

Was this answer helpful?
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
  1. Home
  2. Questions
  3. Dead truck battery every time it's left off for a few hours.

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: i get a check engine code p0351

Generally, this code points to a malfunction in the primary or secondary ignition coil circuit. Your vehicle has one ignition coil that sends spark to a distributor which then sends the ignition spark to the cylinders in a specific order....

Q: Camshaft position sensor on my Lexus

Hi there. A bad camshaft sensor can cause it to run similar to having bad fuel. As for the recall, the dealer does not need to do a recall if that part was already worked on by another, non-dealer mechanic....

Q: Check gauge light is on and Battery voltage is dropping. The battery is failing to stay fully charged.

Hi there. First the battery will need to be charged to 100% charge of 12.6 volts. Then load test the battery and see if the battery can hold a charge after a load for 30 seconds. If the battery can...

Related articles

P0052 OBD-II Trouble Code: HO2S Heater Control Circuit High (Bank 2 Sensor 1)
P0052 code definition HO2S Heater Control Circuit High (Bank 2 Sensor 1) What the...
How to Avoid Back Pain in a Car
If you have back problems, sitting in a car for an extended period of time can be excruciating. Even without back problems, you could experience discomfort and soreness from...
P2428 OBD-II Trouble Code: Exhaust Gas Temperature Too High Bank 1
P2428 code definition A P2428 trouble code signifies that the PCM has detected a problem in the exhaust gas temperature sensor circuit in bank 1, which subsequently contains the number one...