Said It Here

Why do multiple electrical accessories fail when starting the car?

Multiple electrical accessories and systems fail simultaneously upon startup because a single component, such as a faulty ignition switch, a failing main relay, or a major grounding issue, is interrupting power to several circuits at once. This prevents essential features like power steering, air conditioning, and auxiliary devices from operating normally when the engine turns on.

What people tried

Every workaround mentioned in the threads below. We haven’t tested any of them — and nobody here is claiming they worked.

  1. 1
    Checking individual fuses for continuity
  2. 2
    Probing fuse terminals with the car off and ignition on
  3. 3
    Installing a new alternator
  4. 4
    Unplugging and re-plugging the device accessory to force power detection.

In their words

Unedited, most upvoted first, each linked to the thread it came from.

all of those went out upon start up.source ↗

SovietDoge-_- · r/AskMechanics · 1 upvotes

When I turn the car on, the detector doesnt get power unless I take out and plug and put it back in.source ↗

BlackRogue17 · r/MechanicAdvice · 1 upvotes

Where this came up

People with this problem also raised