I replaced my brothers factory head unit a few weeks ago and now his rear speakers are not working. when I remove the harness for the rears the fronts work fine????? i do not think i crossed any wires but I am about to remove the head unit and check. any other ideas????? thanks!! oh his runner is a 1996 limited.

 

I had a similar problem when I replaced the head unit in my 91 4runner. The rear speakers each have their own amp which is turned on by the "power antenna" wire from the head unit.

 

But why do they still not work when I have the antenna cord plugged in??? What is the smaller cord that looks like the peer antenna?? The back speakers worked when I first changed the head unit now they have stoped ????

 

my rear speakers have two plugs. one pair for sound and one pair for power to their amps. test them for power activated when you turn your radio on.

 

I can not find the rear amp? is it located in the back of the truck or up front? I am getting totally frustrated I know it should not be this hard. I did notice that the harness from the truck has six wires on the rear harness and that the radio end only has four??? I dont think that the last runner the head unit was in was a limited which probably mean that it did not have an upgraded system????

 

on the factory plug there is a blue wire. this wire is the same color as the power antenna wire, on an aftermarket unit the rears will only work with the radio on and not anything else, to remedy this just wire the blue from your harness to the ign+ off the back of the deck not the power antenna wire. happened to me and took a while to figure out

 

i don't have the factory rear speakers in place, so i can't confirm that the amps are part of the speaker assy. what i have, is two plugs at each speaker location, with two wires each.

many manufacturers use speakers that are "self amplified", the amp is on the speaker body, and you have to plug in its power as well as the audio.

if you have this set up in your vehicle, then the audio you're sending to those speakers may be only "line level" and need amplification to be heard.


but if you're unsure of whether your new head unit is delivering 4 high-level audio signals, you need to test that first, at the back of the head unit. use the same speaker and connect it one at a time, directly to each of the four speaker outputs and confirm they're all working.

 

Did you try the fader? Seriously, check it out first.

If not, I would take the rear speaker wires at the deck and use a 9 volt battery to "tap the speakers. This will tell you if you have the correct wires and let you know which is left and right. If you can not make the speakers pop with any combination of the 4 rear speaker wires, you may have an amp hidden back there somwhere as has been mentioned above--and the factory does hide 'em!

 

All of the above = true.
Not much mention on the web either but you need to connect the rear speaker power wire to the pwr antennae wire. If you wired up your own harness connector you would have found 1 extra wire that didn't match anything.....that's the one.

 

Reviving this from the dead, Im having the same issue after a factory (Subaru) head unit install on my 88 4runner. The PO hacked up the original factory radio plugs so I found some later 4runner radio plugs (90-92) and started soldering. I pretty much mocked it all up and got it working but the rear speakers are now not working. Here's the part that gots me puzzled, I don't have a blue wire that comes off my the vehicle. Is this blue wire everyone's talking about in the aftermarket radio adapter?Can someone snap a picture of which wire it is? I've looked on http://www.installdr.com/Harnesses/Toyota-Wiring.pdf and cant seem to figure it out. I do have a aftermarket radio adapter that plugs into the head unit. When I looked at this site I decided to pull the "H" "I" terminals and tossed them out because I didn't see a use for them since the site tells you there not being used. Any type of help is greatly appreciated.

 

I tried the connect blue to blue wire method and didn't resolve anything, so instead i hooked up the blue from the new Stereo and spliced it in with the ignition power as well (Red) and BAM i have my rear sound back.

FWIW i also bypassed and removed the front factory Amp