I would think it might just. Most stereos are designed to drive specific load, meaning the unit may be sensing the impedance (load) is out of the range it wants to drive.

Maybe

I put a JVC in my 02 Saturn and didn't have any problems, but I spent the extra $20. Now you are making me glad I did.

Did you solder those wires or just twist them together? If you don't solder, then at least use crimp connections. Twisting does not work very well.

BTW the JVC blew out the factory speakers after a month or two. I now have Polk Audios in there.

there I go --overlooking the simple

i agree with Keith
solder (per keith) and shrinkwrap while you're at it to avoid shorts

This is a little Factoid a lot of folks, including myself did not really know about. Having come from Old School where you wired into the wiring harness. Now having done that on more than a few cars and worked on those were it was done poorly and caused problems standardization makes sense.
But then again more or less when something like this has taken place radio's too have become standard-ized in size and shap which means face plate adapter kits became standardized also. No longer are radio's made to fit a car, the face plate adapter makes a universal radio look as if it belongs on a dashboard which is fine unless you are working with an older car that does not have a hole in the dash the right size for the now universal radio, there are no standardized wiring setups in the car and there are no instructions as to how to wire the radio with out them.

AND you have bought the radio at a swap meet with the wiring harness on the radio pre-cut!

i used a "triple twist" method of connecting wires, and it has always worked for me in the past, in my truck which had no wiring to start with, in my friend's pontiac sunfire that i wires an adapter in and made it plug and play, and in another friend's 77 ford that had no initial wiring... would soldering them make that big a difference?

would it hurt anything(besides sound) if i had the speakers hooked up backward? ex. pos to neg and neg to pos... the factory wiring diagram was a little ambiguous on which wire was which...

Don't know what pictures/diagrams you saw, but there's no ambiguity in the ones I've recommended ...

it was great on all the wires except for the speaker wires. it gives the right colors, but doesn't tell what color is the positive lead and which one is negative.

The diagram clearly shows the "hi" or "signal" side of the circuit with a "+", and "lo" or "return" side of the circuit with a "-". Each wire (both "hi" and "lo") have the color marked as well ......

Both references that I gave you do indicate which are the + and which are the - wires. It does not matter to the speaker if they are backwards, but for sound, they all have be right or they can all be backward, but they can't be mixed or the system won't sound right.

I don't know what a triple twist splice is, but back in the 60's when I started doing things like this, the western union splice was the splice of choice, it is stronger than the wires themselves, but I still soldered the wires afterward. We didn't have heat shrink back then so it got a good cover of electrical tape.

The yellow wire is a 12 V wire, but it only comes on when the key is in the accessory or run position.

My radio is a JVC KD-HDR30

basically, i split the stripped ends into a "V" shape and twisted one side around one leg of the other, then twisted those legs around the leg of the first wire, then twisted those braids together...