I have a 1995 4Runner SR5. When I purchased the vehicle, the speakers were blown throughout the car. I bought new speakers and installed them myself. (Not very hard) The back speakers still don't work. The speaker goes into a "bass box" and the speaker wires go into a green circuit board in the box. My dad has a friend who has worked on Toyota's for years, and he said that you have to re-wire the speakers from the head unit back, because you must have the stock CD player for the back speakers to work(which I don't have) since the speaker wires go into the circuit board which has wires going to several other things. I have gone into Circuit City, who installed the CD player, and when I asked if the back speakers worked, they said yes?????? WTF??? They want $50.00 an hour to "figure out" the problem, then more money to fix it. I am done with them, and unfortunatly, I told them that they never worked in the first place, so they wouldn't fix it for free. I go into Best Buy, and the guy says that there is no circuit board in my bass box whatsoever, but there is obviously one in there. He argues that I'm wrong and he has worked on 4Runners before and there is no such thing. So, do I have to re-wire the car from the Head Unit back to the speakers, or is there a simpler way to get my back speakers to work?

 

Well if that is true, I will find out sunday when my new HU gets installed. I'm 80% sure that that isn't true and that there is just a wiring problem. The harness is what takes care of the connections. The wires from the box go to the tweeters up top, and to the HU, and to the speakers. Have you tried different speakers or checked the connections? Oh, and PLEASE check the fade, often times people overlook that because it is so simple.

Good luck.

 

The rear speakers have their own amp (the green circuit board). With your aftermarket HU, that amp is not getting power. No power to the amp = no rear speakers. Oddly enough, the rear amp is triggered by the radio antenna. When it is in the 'up' position, the amp is powered. I assume your rear speakers work when you are using the radio, but not when playing a cd.

Your power antenna is probably connected to a blue wire from your HU. There should be a blue/white wire coming from your HU which isn't connected to anything. Connect the blue/white wire to your power antenna instead of the blue one. This will give your rear amp power the whole time the HU is on.

 

Yes, the fade has been checked.

ChickenLover, thank you for that. I will check it out soon. I am away from my car right now and won't be back to it for a couple of days, but I will do it when I get back home.

 

and i'm fairly certain that your rear speakers will work without having the factory CD player, mine did, but i of course don't have the 6 speaker set-up either.

 

you can bypass the amp, which i believe is located in the right front kickpanel, by checking the wires that are at the back speakers for color, then coming to the amp and removing those wires from the harness. then trace the wires back to the HU, just solder those wires together, bypassing the amp.

 

Ok. First of all, you DO NOT HAVE TO REWIRE FROM THE HEAD UNIT BACK. I did this not too long ago, and you just have to look for a way to bypass the amp for the back speakers. Start with the front wiring harness, and maybe either look for the same colored wires and just keep those two as a positive and a negative, and disconnect the other wires leading to the back. Then Wire em up to the speakers, and connect them to the headunit. Maybe a small battery and a multimeter would help to make sure you are getting a good connection.

 

I know this thread is long gone... but it just saved me a good 2 hours of interior work..... now if only someone could tell me what my timing issue is lol

 

Having the same problem but used your trick. front and back speakers work for CD, Aux, and USB. Unfortunately for some reason when in Bluetooth mode the rear speakers do not work.

 

Hey guys ive got the same issue. Im trying to install speaker in the rear of my 1991 4runner because it never had any. Im still keeping the factory head unit, but i still cant get the rears to work. Ive read elsewhere that they come from factory with inbuilt amps and that I need to bypass the amp line or something?? Ive had a quick look to see if i could figure it out and found that the plug going to the back has 5 wires in it, 2 for the speaker (positive and negative) and then another 3. Now 2 of these wires are a power source which im assuming would of been used to power the amp?? Then theres the last one, i have no clue what this does, maybe a trigger wire?? Do i need to run like a loop wire or something?
Cheers, Nick

 

The rear amps are triggered by the blue antenna wire. I just installed a new Kenwood head today, w Infinity 5.25" in the rear. Blue wire made it come alive!