As a car owner, I know how frustrating it can be when you start having electrical problems caused by broken wiring. The dashboard lights flicker, the radio cuts out, windows and locks stop working properly - it's incredibly annoying!

When I've taken my car into auto repair shops in the past, the mechanics have always seemed reluctant to share the full details on wiring repairs. They'll replace a wire here or there, which tends to just mask the problem for a while before it returns.

Through my own trial and error working on various old clunkers over the years, I've discovered a secret method that auto experts don't want you to know - a systematic approach to tracking down and repairing broken wiring for good.

In this post, I'll walk you through the steps so you can fix your vehicle's electrical gremlins once and for all.

Step 1: Visually Inspect Wiring Harnesses

The first thing you'll want to do is a thorough visual inspection of all the wiring harnesses running underneath the dash and along the firewall. Pop the hood and use a flashlight to carefully follow each harness from end to end, looking for any obvious damage:

Pay particular attention to harnesses near hot components like the engine and exhaust system. The high heat over time can degrade the insulation and cause shorts.

If you find any visible damage like this, that's likely the culprit for your electrical issues. You'll need to either repair that section of wire with splice connectors or replace the entire harness.

Step 2: Wiggle Test All Connectors and Plugs

Intermittent electrical problems are often caused by loose wire connections rather than the wires themselves.

To find these, start wiggling each electrical connector and plug while the car is running. Turn on various electronics like headlights, wipers, seat warmers etc and wiggle the connectors to those circuits.

If bumping a connection causes your headlights to flicker for example, you’ve identified the loose connection. Some problem areas to check:

Clean corroded connections with electrical contact cleaner spray. Secure loose plugs with a zip tie or electrical tape. Replace any visibly burnt/melted connectors.

Step 3: Check for Continuity in Wires

Now we move on to diagnosing breaks in the wiring itself. For this you'll need a multimeter that can measure continuity.

Turn the ignition to the "ON" position without starting the engine. Take one probe from your multimeter and poke it through the wire insulation to make contact with the bare conductor. Then do the same thing with the other probe further down the wire.

If the multimeter shows continuity (beeps or 0 resistance), you know that section of wire is good. However, if it doesn't, you've found a break in the wiring.

By systematically testing wires in segments, you can pinpoint the location of the break. Repair by splicing in a section of new wire.

Step 4: Power Down Circuits One at a Time

Certain electrical faults like short circuits can cause wiring to overheat dangerously. If inspecting all the wires didn't reveal anything obvious, move on to isolating circuits.

Start by removing fuses one at a time while monitoring your voltmeter connected to the battery. When you pull the fuse that causes voltage to drop to normal, you’ve found the circuit with the short.

Go back and re-check those wire harnesses more thoroughly for any damage that could cause a short. Also wiggle connections to see if the short is due to a loose plug or connector.

Step 5: Bypass Aftermarket Accessories

A common cause of electrical gremlins in older cars is faulty aftermarket accessories installed by previous owners.

If you suspect this might be the case, start temporarily disconnecting or bypassing any aftermarket parts like:

If normal electrical function returns after disconnecting an add-on accessory, then you’ve found the culprit. Re-install the accessory properly, repair or replace it if necessary.

Step 6: Replace Old Wiring with New Harness

Sometimes electrical issues persist even after trying all the above steps. If you have an older vehicle and much of the wiring is brittle, cracked, and patched together, it may be time to replace the old harness.

You can buy a brand new wiring harness that just plugs into all your car's electrical components and totally replaces the old wires. It's more expensive than routine repairs but will give you an electrical system that's good-as-new.

So there you have it - the inside scoop on systematically tracking down and repairing any automotive electrical issue once and for all. Armed with the right knowledge and tools, you can handle these wiring issues yourself instead of paying a mechanic an arm and a leg.

Let me know in the comments if you have any other tips for troubleshooting tricky electrical gremlins! I'm always looking to expand my repair expertise.