sorry, i had to mention that i had an after-market radio, installed it myself
if the tacho signal is mixed up at the radio.. then this means the radio doesn't work if i turn my ignition on (not starting the engine) right?
whell... the radio works like normal on colder day's this way...
i think i put my multimeter on de wires, see what i got..
if the voltage is to low, i will go and look i if can bump it up... see what happens