Skip the auto shop - Our mechanics make house calls

Q: Battery drainage

asked by on

Within the last 6 months, I have replaced my alternator and all the gearing systems, all of my spark plugs, and my radiator/cooling system, yet something is still draining the battery. Every month or so the battery dies and takes 5-10 minutes to successfully jump start the car (no lights come on at all). However, I hooked it up to a battery charger and charged it to a full charge then ran my car and measured all the voltage differences from different areas which all seemed to be correct. I am wondering if there is another place that I am not thinking of that could be draining the battery. Last night I had it parked for 45 minutes to come back to a completely dead car, but it started on the first try this morning right away and ran great.

My car has 230000 miles.
My car has a manual transmission.

A: It is possible to have a bad ground or shor...

It is possible to have a bad ground or short somewhere. Check the connection at the negative battery cable to the engine/chassis. Remove, clean, and reinstall it. Also check for loose connections/ground at the fuse box.

I owned a Jetta of the same generation - 85-92. A common source of trouble is the fuse box under the drivers side dash getting wet. A common source of water intrusion is around the windshield seal as well as a clogged cowl drain under hood. It can fill with water and come through the firewall through the speedometer cable and other things running through the firewall.

If you need some help with getting this fixed, consider YourMechanic, as one of our mobile technicians can come to your home and diagnose the draining battery firsthand for an accurate repair.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Save up to 30%

Get a quote

What others are asking

Q: Won't start the car

You might want to check to ensure all of the connectors are are secure. Sometimes a bad ground or power lead is at fault. By hooking up a scanner, you are completing the circuit through the scanner allowing the vehicle...

Q: car won't start

The electronic noise is most likely the fuel pump operating. The gas smell is concerning. A fuel leak could be dangerous and the risk of an engine compartment fire could result if the vehicle operates for any period of time....

Q: AC not working

The most common cause for AC not working is a leak. Once the refrigerant pressure gets low enough, the system will not work. The vehicle has pressure sensors that keep the system from starting so that you do not damage...

Related articles

How Long Does a Heater Control Valve Last?
Keeping the right amount of coolant in a car is essential in keeping the engine at the right temperature. Failing to have the right amount of coolant or even bad elements...
P0240 OBD-II Trouble Code: Turbocharger Boost Sensor B Circuit Range/Performance
P0240 code definition Turbocharger Boost Sensor B Circuit Range/Performance What the P0240 code means P0240 is an OBD-II generic code triggered when the Engine Control Module (ECM) detects the intake boost...
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...