JVC deck into ST185 w/ Metra harness

Hi, I purchased the Metra harness to put a JVC deck into my 1991 ST185 (I got the pocket as well). Anyway, the wiring is a little confusing to me. The back of the deck only has two RCA inputs (for rear speakers), the front are with wires (there are also wires labelled for the rear speakers, so I'm a little confused with regard to that - can one use the RCA inputs OR the wires?).

Do I need to cut off the other RCA's on the harness to attach the wires to my deck? Will this power all the speakers in the car (using the old amp)? If not, is there a way to get all speakers on without purchasing any more stuff? Any detailed help would be greatly appreciated - thanks alot,

Larry Klassen
PS the JVC deck is model no. KD-S580 if that is needed by anyone helping out.

The headunit has outputs, not inputs, but whatever. :shrug:
You use rcas or wires, not both. You can get rca jumpers that combine 4into 2, you'll just have no fader.....
Don't cut the rca wires, they have the pos and neg. That's the main problem with the sys 10, it only has 1 grnd for all 4 outputs.
With the metra harness it's SUPPOSED to power everything, but I couldn't get it to work on mine, but I think it was a problem between the headunit and amp. :shrug:

I'm a little confused, though - there are both RCA jacks on the harness, as well as separate wires (naked wires, without jacks) for the front and back left and right speakers as well. Can I not just use the front naked wires to the wires on my deck, and the rear RCA's to the RCA's on my deck?

Do you mean the wires and rcas for the headunit harness? Not the Metra.
You have to use all 4 rcas for the sys 10 to work. It is the only way they will all ground.

Okay, so I absolutely have to have a stereo with 4 RCA's, right? Now, does it matter if that stereo has power (eg. 50w per channel)? If I have the stereo with 4 rca's, is this really a simple operation to swap out stereos? I don't want to undertake this myself only to be left with no stereo for a week until I can get a professional to do it for me after I've screwed it up!

And by RCA's, I mean output RCA's on the stereo, as I was corrected earlier. They are the female end, though, so I guess that's why I thought it was input.

Yes, 4 single rca connectors, not 4 pairs. In other words, you have to have a front and rear output.