On Feb 15, 11:31 am, asalcedo wrote:
The light in the boot of my car does not light up.

I have checked the bulb and it is fine.

I have checked the voltage at the bulb holder without the bulb and with
the ignition key turned on and it is 12V

However, when I put the bulb in the holder it does not light up and the
voltage is 0, even with the ignition key turned on.

Where is the fault?

How is the bulb turned on? It's very unlikely to stay on all the time.
I had a similar problem where the bulb was OK and there was voltage to
the connection at the back of the bulb, but no voltage to the contact
that the bulb touched. There was a switch on the wiring diagram but I
could not find it.
I took the bulb holder apart and found a mercury switch inside. The
mercury was coated in oxide. I took the mercury out and cleaned it and
cleaned its container. The switch worked perfectly after that.