Disabling IGNS with the head unit

[Iyse]

Is there any way to alter the confirguration of the head unit so that the key doesn't have to be in the ignition for the head unit to switch on?

(98 W202)

[guydewdney]

yes - theres usually three power based wires +, -, and Ign sense.

+ is red (usually)
- is black green or brown
Ign sense is often yellow - does your HU have a std ISO socket / plug? (1" square plug, 15-20 pins)? if so - look up iso radio plug and make sure you have the ign sense wire correctly identified - connect this to + or a switch..this will fool the raio into thinking the radio is on all the time. Personally I'd connect it to a 2 way switch - pos 1 = on / off with ign, pos 2 = on all the time

Or buy a different radio that has a settable off time after the ign switches off (like blaupunkt)