Where electrical faults come from

A modern car has dozens of computers and kilometres of wiring. When something electrical acts up, the fault is usually one of three things: a part that has failed, a connection that has corroded or a wire that has rubbed through.

Starting and charging problems are the most common. A battery, an alternator and a starter can each cause a no-start, and each one can be tested properly in a few minutes. Testing first means you do not buy a battery when the alternator was the problem.

Signs of an electrical problem

Slow cranking, or just a click when you turn the key
Battery light on while driving
Battery dead after the car sits for a day or two
Headlights that dim or flicker
Fuses that keep blowing
Windows, locks or lights that work only sometimes

How we trace an electrical fault

01
Battery and charging test
Battery health under load, alternator output and starter draw.
02
Drain test if needed
We measure what the car draws while it sleeps and trace the circuit that is staying awake.
03
Trace the fault
Wiring diagrams and voltage-drop testing to find the bad connection or wire.
04
Repair and retest
The fix is confirmed with the same test that found the fault.

Battery and electrical questions

Is it the battery or the alternator?

If a boost starts the car and it keeps running, the battery is the first suspect. If it dies again while driving or the battery light is on, the alternator is not charging. A proper test of both takes a few minutes and settles it.

How long does a car battery last?

Typically three to five years. Cold winters and hot summers are both hard on batteries, and short trips never fully recharge them.

Why does my battery keep dying overnight?

Something is drawing power while the car is off. Common causes are a module that does not go to sleep, a glove box or trunk light that stays on, or an aftermarket accessory. A drain test finds which circuit it is.

Does a new battery need to be programmed?

On many BMW, Audi, Volkswagen and Mercedes models, yes. The car adjusts its charging to the battery's age, so a new battery has to be registered with a scan tool or it can be overcharged and fail early.