Door locks don't draw much current, but if the car's battery has a shorted cell, it will draw down the voltage from the jumping vehicle. The lock motors won't work well with low voltage. Be sure the jumper cables are making good connections. Turn on the head lights and watch their brightness while you wiggle the jumper cable clamps.
There is always a mechanical way to unlock doors from the inside, unless you have child lockout switches that require the doors to be open to switch.
If your battery is okay but it just was run dead, it can take up to fifteen minutes with a battery charger or jumper cables before it STARTS to take a charge. It takes time for the acid to become conductive and let current flow through it so the battery can recharge. You may need to charge the battery for an hour or more at a slow rate.
Aug 24, 2015 at 4:07 PM
