1. A vac link to your climate control, most likely causing the no-kill with ignition symptom youre having (try turning the key off with this plugged).

2. I BELIEVE (don't quote me):
Brown = ground
Red = switchable (your looks like mine, no constant, though others on this board will swear one is present)
I think the black and grey run to your console fader, then onto your speakers
The blue one is the signal for your auto antenna (to make it go up and down as the radio is turned on and off)

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1989 300E 144K