Common causes
- Old or heat-damaged battery
- Failing alternator or diode
- Glovebox, trunk or dome light staying on
- Aftermarket stereo, dash cam or tracker
- Module not going to sleep
- Corroded terminals
How a drain test works
We connect an ammeter in series with the battery, let the modules sleep, then pull fuses one at a time to find the circuit drawing power.
Fixing it
Most drains are fixed by repairing a switch, relay or wiring, or removing a faulty accessory.
