Auto Repair: Jump-Starting Diesel Batteries
Even though diesel-powered vehicles can have dual batteries or one oversized battery, it's possible to jump-start a diesel from the battery on a conventional gasoline-powered vehicle. To avoid confusion, in this section I call the vehicle with the dead battery the disabled vehicle and the one you're jumping the start from the source vehicle. Follow these steps to jump-start a dead diesel battery:
- Make sure that both vehicles are in Park or Neutral with the parking brakes on.
- Turn on the heater on the disabled diesel vehicle to protect the electrical system from surges in voltage.
- Make sure that the lights and other electrical accessories on the disabled diesel vehicle are off.
- A vehicle with dual batteries usually has thicker cables on one of the batteries. If either vehicle has dual batteries, always attach the jumper cables to the battery with thicker cables. If either vehicle has dual batteries with cables of the same thickness, use either battery for the jump. If a vehicle has only one battery, just be sure to hook the cables up in the proper order.
- Connect the clamp on one of the jumper cables to the positive terminal of the disabled vehicle's battery. The positive terminal should have a (+) or a red cover on it.
- Connect the other end of the same jumper cable to the positive terminal of the source vehicle.
- Connect one end of the other jumper cable to the negative terminal (-) of the source vehicle.
- Here's the tricky part: Connect the other end of that jumper cable to an unpainted, metallic part of the disabled vehicle. I often use the bracket that keeps the hood up, but any such part will do as long as it's not near the battery, belts, or any other moving parts of the engine.
- Start the engine on the source vehicle.
- Start the engine on the disabled vehicle, and let both engines run for a minute or two, more if the battery has been dead for a long time.
- Turn off the engine of the source vehicle. (Leave the disabled vehicle's engine running.)
- Remove the cable from the unpainted metal part of the disabled vehicle.
- Disconnect the cable from the positive terminals of both vehicles.
- Disconnect the cable from the negative terminal of the source vehicle.
- The disabled vehicle should be driven around for at least 15 minutes to ensure that the battery is fully charged.
Tip: If you jump-start a dead diesel vehicle and the battery dies the next time you try to start the car, you probably need a new battery. Be sure to get theproper one for your vehicle's make, model, and year.
From Auto Repair for Dummies, copyright © 2009 by Wiley Publishing, Inc., Indianapolis, Indiana. Used by arrangement with John Wiley & Sons, Inc.