How to Rewire Your Car and Avoid Costly Mechanic Bills

Rewiring your car can seem like a daunting task, but with some basic knowledge, the right tools, and taking proper safety precautions, I was able to rewire my 2001 Honda Civic and save hundreds of dollars in mechanic bills.

Reasons to Rewire Your Car

There are several good reasons why you may want to consider rewiring your car:

• It can save you money - Mechanics often charge $100/hour or more for labor to diagnose and fix electrical issues. Rewiring it yourself saves on these costly labor fees.

• You can upgrade - Rewiring gives you the opportunity to upgrade wiring, connectors, fuse box, etc. This can provide improved reliability and prepare the car for adding new electronics like a sound system.

• You gain knowledge - By rewiring the car yourself, you'll gain invaluable knowledge about how automotive electrical systems work. This knowledge can help you diagnose and fix issues down the road.

• It can be safer - Old, cracked, damaged wiring is a fire hazard. Upgrading old wiring reduces the risk of dangerous electrical shorts and fires.

However, there are risks if wiring is not done properly, so safety must come first.

Safety Tips When Rewiring Your Car

Working with automotive wiring can be dangerous if proper precautions are not taken:

• Disconnect the battery - This should be step one before beginning any work. Remove the negative terminal from the battery to cut all power to the car.

• Wear safety glasses - Protect your eyes from debris while working under the dash.

• Avoid shorts - Be cautious not to let wires or tools short out connections. This could cause damage, injury, or fire.

• Use proper tools - Use wire strippers, crimpers, connectors, heat shrink tubing, etc. Never use teeth to strip wires!

• Install fuses - All new wiring should have proper high amperage fuses installed to protect from shorts.

• Follow diagrams - Use wiring diagrams specific to your car's make/model/year for reference. Don't guess.

• Work methodically - Stay organized and document everything thoroughly. Label wires and connectors.

By making safety the top priority, you can complete your wiring upgrades successfully.

Steps to Rewire Your Car

Here is an overview of the key steps to safely rewire your car:

1. Create a Plan

• Research wiring diagrams for your specific vehicle

• Decide what wiring you want to replace/upgrade

• Make a plan - sketched or digital diagrams are extremely helpful

2. Purchase Supplies

• Wire - use high strand count tinned copper automotive primary wire

• Connectors - quality insulated OEM style connectors recommended

• Terminals - crimp, solder, heat shrink style

• Fuses/fuse blocks - high amperage fuses or fuse/relay boxes to protect circuits

• Tools - wire stripper, crimper, cutter, soldering iron, heat gun, etc.

• Cable sleeves/looms - protect wires from rubbing/shorts

3. Remove Old Wiring

• Take photos to document original wiring before removing

• Label connectors and wires before disconnecting

• Remove old wiring carefully without damaging connectors

4. Install New Wiring

• Route new wiring carefully without interference / rubbing

• Use cable sleeves/looms to protect wires

• Crimp or solder quality insulated terminals

• Connect labeled wires/connectors to match diagram

• Include fuses in all new wiring

5. Secure and Check Work

• Use zip ties to secure new wiring in place

• Seal any holes into cabin with silicone

• Check for rubbing/shorts/loose connections

• Verify fuse boxes secured and easily accessible

6. Reconnect Battery and Test

• Reconnect battery starting with positive terminal

• Turn ignition and test all systems - lights, engine, electronics

• Start engine and test alternator charge

Take the time to be thorough and don't skip safety steps. Your upgraded wiring will provide trouble-free service for years to come. Let me know if you have any other DIY car electrical questions!