Radio comes on then go,s off in car?
Answers:
Sounds like a loose connection or a short.
can you be more specific ? duration, physical changes or so ?
What car is it and what radio is it?
If it is a new car (peugeot, citreon) then it may be a complication with multiplex wiring. Which unfortunately can be a nightmare to sort out and often voids your warranty on your car. The multiplex connectio often look the same as the ISO connections on the radio but the pins are configured differently hence the odd operations of the unit.
If is not a new-ish car, then I would check the radio first, by trying it in a willing friends car to see if it is the unit at fault. If not it is probably a change in the wiring, (VW) you need a wiring harness, (Vauxhall) you need to swap the red and yellow wires around etc.
Failing that you need to speak to a audio specialist about the problem
Hope it helps
The answers post by the user, for information only, UKQnA.com does not guarantee the right.