Skip the auto shop - Our mechanics make house calls

Q: Can't find a parasitic drain?

asked by on

I have went through the fuses looking for where the drain is coming from, the only thing I haven't checked is the amp. But I rarely tour stereo on, could this still be the culprit?

My car has 152400 miles.
My car has an automatic transmission.

Yes, your amp could be staying on. Feel it and see if it’s warm. Disconnect it to confirm. Using a low amp probe (amp clamp) around the battery cable is the easiest, most repeatable method to measure battery drain. Measure the B+ wire at the alternator as well. Feel relays for warmth and key out of the ignition while doing this. Remember it can take 10-30 minutes after running for all modules to go to sleep. If you pull a fuse then put it back it can wake up a control module. You have to leave it out and move on with testing. Instrument cluster and rear wiper motors are a possibility, too. There is a lot of electrical content in your car, so you may want to double check the fuses. You’ll also want to verify whether the battery really is good! If you are still having trouble, you can always get a certified technician from YourMechanic to come to your car’s location to diagnose your battery and let you know what needs to be fixed.

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・Fair and transparent pricing

Get a quote

What others are asking

Q: Clicking when letting off the gas pedal.

The differential inside the transmission may be worn or have an issue with the bearings that is causing the clicking noise when loaded on the opposing side to the load applied when driving. Try to see if the noise occurs...

Q: Difficulty shifting into first gear

It is possible that the clutch itself may have been worn down to the point where it can no longer engage the correct gear. Clutches are made of the same material as brake pads and can wear down over time....

Q: What was the device that prevented my car from starting and blew a fuse? Is it safe now?

This sounds like an aftermarket addition, which are often wired in pretty poorly by people that install them. I would suggest having the car inspected by a qualified technician, such as one from YourMechanic, before doing any long drives with...

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...