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Car stereo amplifier removal?

I bought a 1992 4Runner and it has a pioneer stereo in it that will power on and functions in every aspect except sound coming out of the speakers. It appears that the previous owner had an amplifier hooked up to it? There was a cut ground wire attached under the rear seat, and a wire spliced into the blue wire coming out of the wiring harness near the back of the deck. I don’t want to invest in an amp, I’m afraid that it would increase the value of my truck too much, is there a way to “reset” the stereo? Is it thinking that there is an amp, so it’s not working? Thanks in advance for any help!

This is the specific stereo.

The head unit has a built in amp with 22w RMS per channel. It also has a subwoofer output so the external amp may have been a subwoofer amp only. If it has the factory speakers, even as little as 22 w RMS per channel will blow them out easily. Have you checked to see if even has speakers? If the amp was taken out, they may have also taken any aftermarket speakers also because those can run upwards of $500/pr.

They were probably feeding the speaker out from the radio to the amp and now the amp is gone. Do you have the original factory plug for the radio still there or they have spliced into it.
If the wiring is intact, it would be easier to fix, otherwise you need to do investigative work.
If you don’t want to do it, a good stereo shop should be able to fix it for less than $50.

Nope… If there was an Amp…the wires from each speaker should be running to IT. There are several ways to install an Amp…or rather more than one way to install it I should say. I installed them professionally for over 10 yrs. You can get sound back but it will take some work. Best thing to do now is to just finish the Amp install that you have there… Or you need to rewire each speaker so that the speaker wires are present at the radio cut out…currently they are where the Amp was located. You arent going to “Reset” anything without some manual labor involved.


Here is a diagram of the factory wiring.

An update: The speakers appear to be aftermarket, they are Hertz brand. I assume that was not what Toyota put in their 4runners.

Do you think that those will handle 22 w RMS direct from the deck?

The main reason it doesn’t make sound is the wires from the back of the deck go no where! They were all cut about 2-3 feet from the speakers. The history of the truck; it was sold to a pawn broker and I’m thinking the owner who sold it took out the amp and some speaker wires?

Thanks for all of you helping, I’ll post what happens after I wire some speakers. Any suggestions on what gauge wire to get would be welcomed.

The speakers should work. The only failure might be if they are different ohms which I would consider unlikely. Standard speaker wire should be fine. Probably 14 guage, maybe 16.

I looked at their spec sheet for the coaxial speakers which I assume is what you have and the 6.5" round will handle 100w continuous. Since they don’t specify whether the continuous is peak power or RMS, then you can assume that they will handle 60w RMS.

If you are using the head units amp only, then 22w can get by with 18 ga easily, but 16 would be better, especially if you later decide to put in a larger amp for some reason. If you go over 100 w RMS per channel, you will need to go to 14 ga.

The speakers you have are high efficiency speakers claiming 92 dB SPL. They don’t specify at one meter, but that is the standard and that means they pump out a lot of volume for a small input. That’s 92 dB per watt at one meter from the speaker cone. And thats per channel. Four of these speakers combine to hit your ears with 98 dB. That can cause a permanent hearing loss if exposed for more than 4 hours continuous in a 24 hour period. Crank it up to 4 watts and you are in the danger zone for a permanent hearing loss if continued for 2 hours or more.

However the road noise in your vehicle could be 90 dB or higher at 70 mph which would mean that you would need most of that 22 watts to hear the music clearly. Vehicles just don’t make a good environment for listening to music.

My most enjoyable car stereo, 03 ranger short cab, 4 bose speakers and an alpine radio cd unit, have not gotten close to the quality and enjoyment in a sound system ever, home or auto. Road noise? what road noise.

Oh Barkydog, don’t bark up that tree.

@keith not sure what you mean but bark up that tree or pee on that tree, or smile at that tree my 3 choices

If mike sees your post, you will know what I mean.

Update: I was looking for speaker wire to salvage, and when I found some I went to see what color goes where on the diagram Knfenimore posted, then I thought maybe the factory wires are still in place? They were! At least in the front, so that is what is hooked up now, and it works good enough for listening to car talk! I Imagine the rear door speakers have factory wires to them as well, but I didn’t want to tackle taking on and off door panels today. Thanks for all your help, if I remember to do so, when I finish it I’ll update and say thank you again!

Thanks for the update. Its nice to get a little feedback once in a while.