ToyotaViejo

It's been a nagging issue, but my 1990 had the double-din factory AM/FM Casette/Single CD deck in it. The CD player died, and the tape deck stopped working, so I bought a single din Pioneer CD/iPod deck last fall.

I followed the install kit instructions, and found that there's something different about my truck; possibly because it has every option available except leather seats.

This is about the 50 millionth deck I've installed, but this one blew a fuse and fried the dash dimmer. The dash lights work fine, but only at one brightness. The "painless" harness kit for the second-generation 4Runners just didn't match up with what was under the dash. The connectors were right, but the wires weren't.

After DMMing my way through the wiring harness, I got the stereo working just fine. But only in the two front speakers. Nothing in the rear. I plugged the old stereo back into the harness, and the rear works.

Long story short, there is, apparently, a factory amplifier for the rear speakers. A professional installer I know in another state told me that it's in the dash, behind the glove box. I've gone through every inch of it, and it's not there.

I had the entire dash, both b-pillars and much of the headliner down to remove the factory port-installed alarm (a hundred or so feet of wire in all). The factory stereo head didn't talk to the alarm, so that's not the problem. The alarm had its own brain, unlike many of today's factory anti-thefts.

Does anyone know where the heck the factory amp is (it's not listed in the TTORA FSM linked all over the internet)? Pictures?

I'm now thinking it has to be under the plastic fender/wall liners in the cargo area, but those things are a total PITA to get out, and I'd rather not start ripping unless I know for sure where's I'm digging.

There was no obvious place to hook the new deck's amp signal wire to the harness, and the truck has long since had the motorized retractable antenna replaced with a floppy whip, so the antenna motor wire is doubled over and capped.

Bassmastry101

iTrader: (1)

Not sure about the 90 4runner, but in my 86 the rear speakers had an amplifier attached to them.

ToyotaViejo

Yeah, I'm 99% certain there has to be an amp somewhere. There's no signal in the rear. Not even a ground-loop hum.

Bassmastry101

iTrader: (1)

It might just be easier to pick up a roll of speaker wire and rewire it. That way you won't be reusing the worn out wires going to your speakers. Maybe pick up some new speakers while your at it? 22 year old speakers are probably going to sound like crap with a new head unit.

ChefYota4x4

iTrader: (5)

I agree with Bass...... I ran new Monster Cable to the Back, under the carpet/carpet-to-door trim, and up through the rear panel behind the Seat belt area, then through the back panels. BUT, since then, I've pulled that back out and run wire to 6x9 Boxes with 4Way pioneers. This way, I can put them on the roof, on top of my TOTALLY stuffed cargo area on camping trips, etc.

If you already did run new wire.... then I would think you possibly blew a 'channel' of the built in amp/components of the Deck you installed(had an incident with???).

Bassmastry101

iTrader: (1)

Chef makes a good point about the wiring. If the wiring was all messed up you could have blown your amp inside the head unit. Quick way to test that is reverse the connections from front and rear (switch both white with green and both grey with purple) and see if the front ones will come on. If they do then you can rule out your head unit and find your stock amp. Make sure you switch the wires back the way they were so your fader will be correct.

ToyotaViejo

Sorry for the late reply.

Nope, the head unit is fine. I thought of that first and wired it up to a battery and four auto speakers I had sitting in my shed.

I would be inclined to just run new wiring to the cargo area except I don't like to stack troubles. It just makes problems down the road harder to diagnose.

There is still a wired and, likely, powered amp(s) floating around somewhere in the truck that I'd like to disable and remove or, alternately, fix and use.

I'd just rip out the cargo paneling and look around, but it's already in poor condition thanks to the P/O, and I'd rather not risk completely destroying it to get back there unless I know I have a need to be back there.

It's so weird that the FSM doesn't include information about it. I even borrowed my buddy's 1990 FSM and it doesn't mention an amp or, for that matter, the Toyota-labeled and part-numbered alarm that was in the truck.

My local dealer confirmed that Toyota did offer a port-installed "factory" car alarm - and knew that it was installed in one of two ways depending on if it was installed at port or at dealer. Mine was a port-installed version.

No one seems to recall what stereo options might have been port/dealer options as opposed to straight factory.

SacRunner

My '91 4Runner had the premium sound system, double-din CD/Cassette combo. There are 2 amplifiers, 1 at each of the rear speakers and an "extra" module that sat down below the receiver.

You're looking for that "extra" module and you want to remove it, there are 2 blue square/rectangle connectors that plug into it that have the connections to the rear speakers. I have had 2 different head-units in over the last 10 years and they both have worked with the factory rear amplifiers (with new 6.5" speakers).

Sorry I can't be more informative, but it was 10 years ago that I did the initial stereo swap and I had all the tips and tricks and a 1-800 that Crutchfield had to offer.

ToyotaViejo

Thanks! That is exactly the information I was looking for. In the meantime, I did some digging, and the problem goes a little deeper.

I'm somewhat hard-of-hearing (but not legally deaf; wear ear protection!!!) and didn't notice that with the old stereo, only one of the rear speakers worked. I know because there is only one rear speaker.

It would appear that the P/O spliced speaker wire into the wire outs for the driver rear speaker to hook up a subwoofer or something. As soon as I pulled the plastic, about six feet of wire (complete with two wire nuts) fell out of an empty speaker hole.

I suspect that the P/O probably fried one of the rear amps with this little experiment in redneckery.

So, since I have to take all the plastic liners out anyway to change the missing speaker, I might as well yank the amps and run new speaker wire. In fact, I'll probably add a tap so if someone wants to add a speakerbox later, they can tap in no-cut.

Myself, I',m a middle-aged guy who could care less about going bump-bump down the street. I'd just like my NPR quadrophonically and at reasonable volume.

I'll snap some pictures when I do it.

coreman23

I have a 90 and just went through the same thing. I hooked everything up and the rears weren't working. After research, I found that my 4runner had the amps within the rear speaker boxes. Once you pull the boxes to replace the speakers, it will become clearer for you. (I didn't have the front amp though, I would assume you would run across the wiring for it in the harness though, there aren't that many.) Originally, I wanted to keep it stock, but they just wouldn't work, so I just ran new rear wires. Didn't take that long either and now they work great!

MaK92-4RnR

pulled a stereo out of a 97 4Runner and the amp was right behind the stock stereo. hope this helps.

ToyotaViejo

I just wanted to confirm that after pulling the center trim piece off the lower dash and looking at the back of the original stereo (in my shed, not in the truck), all of the harnesses plugged into the original head, and there is no evidence of an amp or controller in the dash. Everything seems to be in the cargo area adjacent to the factory speakers.

Killemall

I just installed a new head unit and 4 new speakers in my '94 pickup. I'm getting no sound from the rear right side even with the new speaker in place. With the old setup it didn't work either so I think the factory amp mounted in the wall is fried. Any suggestions on how to check for that? Is it replaceable or can be bypassed?

ChefYota4x4

iTrader: (5)

I'm not sure about this year, but I just was dealing with some of this in my 87 4 runner with an 89 body swap. The wires going to that amplified speaker, which is obviously different, since the amplifier I believe was on the speaker, is a set of 5 wires. There are color codes listed all over the internet for which ones fire just the speaker.





I believe from what I read they are the same color schematic. I was able to get power back there by removing those two wires from the connector, by pushing down the pins and pulling them out, and touching them to the speaker. However, I obviously wanted to run larger wire, since I'm running two amplifiers, so I simply deleted using that connector at all even wrapped up the front speaker wires out of the Toyota harness and didn't use them. You don't mind using and running new wire, you can do that simply of the aftermarket radio harness. Plug in the Toyota adapter, wiring up everything from the aftermarket stereo connector wiring to the Toyota adapter plug and then simply do not wire the front or rear speakers off of that adapter connector, and run fresh wire straight from aftermarket deck connector wiring straight to all four speakers.

If you want to use the factory wiring I suppose you will have to bypass that amplifier, I believe you can simply remove the two wires from the connector that goes for the amplifier before the speaker, yellow and white, and run them directly to your replacement speakers. From what I understand, most aftermarket decks going to have more power than those stock Toyota amplified speaker amplifiers anyway.

I think you should probably wait for someone that's more professional to give you advice on this, but I did just successfully and cleanly wire up in a 20 amp system too 4 new speakers and a sub, it sounds fantastic! ..... Oh yeah, and I did just stay at a Holiday Inn Express! Lol. Just kidding, I did not

drpdmazda

BRING OUT YOUR DEAD! BRING OUT YOUR DEAD! almost two years to the date from the last post. ha ha. search the forum, you will be surprised what you can find here.

Killemall

Thanks man!! I really appreciated the inputs. I'm gonna try to troubleshoot the speaker factory amp but I'm glad to know I could simply bypass it. Going with a new after market amp will be my next option.

Yeah, great forum with ton of knowledge . I've been lurking/searching for a while.

ChefYota4x4

iTrader: (5)

Sure... Another helpful diagram of Toyota radio wiring harness connectors.....



Open that picture in the browser, it's probably too small to see on the app. Better yet do it on your computer and you'll be able to see and just make a copy from your printer