Car Stereos: Speakers dead/ low-line system no amp/ ipod interface installed, pioneer deh, rockford fosgate

Question
Hello,
Full History: Hyundai 05 Elantra sedan

-replaced OEM head unit with Pioneer DEH-P3100 (bought harness and sodered/etaped all connections solid.)

-replaced front speakers with rockford fosgate same dim. (stuck on a few bass blockers)

-left OEM back speakers alone but stuck on bass blockers.
 ran peachy for a year or so.

-installed Pioneer IPOD interface CD-IB100II behind head unit (installed correctly) had to coil excess cables yellow/black power bit messy but secured to frame. Used DIN connector from CD-IB100II to back of head unit.

 ran peachy for 3 months with Ipod line in, then crap hit fan.
I lost sound from right front speaker, then later left back speaker, now just down to right rear, and if I bang on head unit or hit bump in road the left front comes on for a few seconds.

Troubleshooting--cut out bass blockers in back (just cause) continuity check good from back of head unit harness to all speakers. Tested new working speaker on bad OEM rear left speaker terminals with no result.

Visited various forums to check if it was an amp issue, only to find my car has NO amp! ...discovered after tearing out half my trunk in the place the shop manual said it'd be.

So, guess Ive got a "low-line" system?

Bottom line is I just want sound in my speakers back, I know they all are good. Sound dosent have to be great, just needs to be there.

Looking for a no/low cost solution. Any Ideas? Please?

btw-the audio fuse in passenger compartment is fine.

I just want sound from all my speakers back, dosent  

Answer
Hi Fred,

If you don't have an amp, then your deck is amplifying for you, and then sending the signal in a high level wire to the speakers.

Where did you test continuity of the speakers to the deck?  At the harness?

If so, you might have an issue with connectivity between one of the harnesses (the deck's, or the aftermarket one you used).  Check those.

Also, test the impedance across the two terminals of all of your speakers.  They should be at or around 4 (with a little bit of give either way... ~3.6-4.5 is generally OK.)

If one of them comes back intermittently, then it's almost certainly just a connectivity issue somewhere, and you just need to locate it.

Check the harness going into the deck (the one that came with the pioneer).  Make sure all of its pins are clipped in securely and none have come loose.

Also make sure that when the deck is pushed all the way into the dash nothing is being pinched/bent.

These problems are always a total pain in the ass to figure out. :\

Justin