wiring problem on mj

i searched for this and i couldnt find anything on head unit wiring like what i had but i got a 1987 mj they dont make a wiring harness for my truck but i have 2 black wires 1 is a ground i have a orange wire that goes to ground a purple one that is hot when i turn the key on and a green one that goes to my 2 speakers that i have in the doors does anyone know were the other black wire goes or does and why do i have 2 wires that go to ground?

spkr grnd and seperate unit grnd try the12volt.com

Re: Radio wiring problem on 1987 mj

I just put a CD player in my 87 XJ. The XJ has 4 speakers, so that pulg will be different, but I would expect the plug that carries the power wires to be the same. The power plug pins are marked A through H, with only the first 6 being used.

A - Pur / Wht + 12 V switched
B - Blk - Ground
C - Or / Wht = Dash light dimmer circuit
D - Pink + 12 constant to hold program memory (schematic says this is red, mine may have faded)
E - Or = Illumination, + 12 V when lights are on (schematic calls this conneciton "Park" and shows the color as blu)
F - Gry - +12V out, switched by radio to power antenna or amplifier

My speaker color codes, the first 4 are likely the same as yours:

LF- Blk / Wht
LF+ Grn
RF- Blk
RF+ Wht

LR- Brn / Wht
LR+ Grn / Wht
RR- Brn
RR+ Wht / Blk

Let us know how these colors map to your MJ.

I have a 89 MJ and those colors seem to be right. The plug should be the same.