installed a 6 disc changer in the boot,
now electrics fu(ked .
when driving in 5th and engine revs under 2000 about, and the highway goes uphill or you have to take someone over and push the pedal, engine sets itself in 'alarm condition' : no turbo, max. revs are about 1500, car doesn't respond to pedal or very late and little, ...
you have to turn off the engine (key to position 0), start again and alarm condition is over. happens only in 5th and when doing low revs. very annoying and dangerous (car gets slower dramatically on highways, without brake lights or anything)
but is over as soon as you shut donw the engine.
What could cause this? and what could be the cure?