Ancient Radio Wiring

I’ve got an old AM/FM/Cassette in my boat. I’m replacing the speakers (4), but the harness is wired unlike any system I have seen before. There’s 8 wires coming out of it. Red and black are obviously for power to the unit. So that leaves 6 wires for speakers. I’ve got a blue, white, green, orange, brown, and grey wires. Anyone have an idea how they should be matched up? The radio is a “Sparkomatic” if that helps.

I’ve wired my share of these before, but they’ve all been newer and this one just doesn’t make sense to me.

Thanks!

could it be that a few got yanked out of the back of the deck? 5 wires for 4 speakers makes no sense at all to me… this is how most are setup..

Constant power: yellow
Ground: black
Speakers:
-Left front (+) white
-Left front (-) white/black
-Right front (+) gray
-Right front (-) gray/black
-Left rear (+) green
-Left rear (-) green/black
-Right rear (+) violet
-Right rear (-) violet/black

Nope, there’s only 6 wires there. Can a ground wire be shared between two speakers?

sry man, i dont know eletrical enough to make that call for you..

Is it meant to have 4 speakers connected? almost sounds like a 2 speaker system. Is it possible that somebody just tied an additional set of speakers into it? If that is the case, pay attention to the ohms if you replicate it. I don’t remember how that works, but I know it has an affect.

3 wires are for the front and 3 wires are for the rear speakers. The fronts share a common(-) and the rears will also. Which color does what is a good question. If you can’t find a schematic you will have to figure it out by trial and error. Turn balance to one side and fader to front and see which two wires will power a speaker. The dull color of the two is typically the common. Then turn balance to the other side and find which works with one of the wires that powered the other front. Then do the same for the back and mark them all. It won’t take too long once you start narrowing it down. Good luck.

A little 9v battery will do the trick also. Unhook all the wires and touch what you think is the negative speaker wire to the neg on the battery and then touch what you think is the positive speaker wire to the other side of the battery and the speaker will make some noise. Try different combos until you figure out what wires are what. you won’t hurt the speakers

yep, common ground front and rear so you can use the fader, as far as colors for what speakers, find a old car audio installer or google it.

Thanks guys. That is kind of what I was guessing, so I am glad someone could offer some advice. I’ll figure it out!

Got it figured out!