New stereo and factory amp bypass

[85badger]

My factory stereo was seriously lacking in performance in my 1995 Land Cruiser so I decided to upgrade to a Kenwood DDX371 Touch screen unit. I purchased the Metra 70-8112 Harness to connect the new stereo harness to the factory harness (white connector) behind the stereo. I drove it for about a week in this configuration but the new sound wasn't what I was expecting, so off to Mud to find a solution! I read through many different threads saying to bypass or remove the factory amp in order to let the new stereo power the speakers. I decided that this was the solution to getting it to sound better. The threads stated that I needed to get a different harness other than the Metra 70-8112. This new harness was the Scosche TA02B. In most of the threads it stated that I needed to add 20" of wire to extend it from the back of the new stereo to the amp location near the passenger right knee. I can follow instruction good enough so that's exactly what I did, however once I routed this harness and tried to plug into the male connectors that came off the amp, it was a no go, they didn't fit! Off to Mud again to figure out where I went wrong. I noticed in a lot of the pics that some rigs have 3 connections at the amp where I only had 2. Could this be the difference between the Land Cruiser and the LX? I don't know but it didn't work. I stumbled upon a thread that said to connect this harness to the 2 gray (previously unused) connectors behind the stereo. It worked and sounded much better too! Problem solved! Hope this helps someone else.

I wanted to post this because I found some of the threads very confusing and in my case not accurate for my application. Over all I'm happy with the set up, however the screen does have a glare issue. Another odd thing, my front door speakers do not work in any of the configurations but the little dash ones do...not sure about that.



Another thing I was having problems with is the DVD player, it seems you have to hook up a wire for the Parking Brake switch in order to have it work. I just grounded it to the chassis of the stereo seems to work fine.




Metra 70-8112 harness used to connect the factory (white connector) to the new stereo utilizing the factory amp.





Schosche TA02B harness used to connect the 2 gray connectors to the new stereo in order to bypass or remove the factory amp.





Completed harness





2 connectors at the factory amp location





Connectors behind stereo. The 2 on the right are gray in color and the ones that I connected to. The white one is unused.





Stereo





Factory Amp removed

 

[stu8319]

So am I understanding this correctly? Toyota has a plug sitting back there unused in the event that you want to bypass the amp? Seems nice of them! I'm getting my stereo in the mail tomorrow and I know it has the kit with the rcas so I'm going to just run some speaker wire down to the connector at the amp the12volt.com has the wire colors spelled out so it shouldn't be a deal.


...via IH8MUD app

 

[85badger]

On mine, yes. There are 2 gray connectors that are unused by the factory stereo. The factory stereo connects to the white one. Also don't forget to unplug your factory amp or just remove it.

 

[JCruse]

Yep there's plugs to use the amp and others to bypass it. I bypassed it to use my own amp. Just one thing, I figured why go to the trouble to disconnect the factory amp since it's not any part of my new system. That was until the first night when I turned on the headlights and got some low buzzing noise out of the front speakers. Yanking the two connectors off of the factory amp fixed this. So IMO take the glove box door off and yank those plugs!

 

[Razor One]

Maybe the 3rd connection on the amp that you didn't have is the lx 450 sub or cd-changer. If I plan to bypass the amplifier on my lx 450 and remove the sub and cd changer, do I still need the metra 70-8112 ?

 

[abrumley]

Stop showing your gd stereo off while my rig is in pieces! Ugh i know where you live haha!

 

[Stevesnj]

I'm installing my Kenwood DDX271 today and have unplugged and removed the factory amp and My question is why do I have to bypass an amp that isn't there? What purpose do the grey connectors serve?

thanks

 

[ppc]

The grey connectors go directly to the speakers as do the outputs on the amp. If not disconnected they fight each other essentially. Removal of the amp is all you have to do. There is no other bypass required.

 

[mdandashly]

This may help and it may just confuse you, but when I did the swap in my 94, I unplugged the amp from the PS kickpanel and there was a factory pre-wired bypass behind the factory deck.

 

[Stevesnj]

The grey connectors go directly to the speakers as do the outputs on the amp. If not disconnected they fight each other essentially. Removal of the amp is all you have to do. There is no other bypass required.

Thanks

 

[Bella1992]

I bought a clarion 4 channel amp. do I disconnect the factory one? I also have new Rockford Fosgate component up front and infinity 2 way speakers in the rear doors. I'm rocking the factory LX Sub and the cd changer. I bought a new 2 ohm 5 inch sub (Polk) to replace the cardboard factory sub. I also installed a bazaooka bass tube with it's own amp in the rear of the cabin. Very clean install, I removed all the plastic panels on the passenger side and had the front seats out as well. My wife came out to the garage, and went back inside shaking her head.

 

[LandCrusher'70]

I just installed the same HU in my '97.
It sounds great, however my rear speakers are not working!!

I am using the two grey plugs.
I have disconnected the two plugs from the factory amp.

I had zero issues with the rear speakers prior to the install...

Any ideas??

 

[Nbest]

I just installed the same HU in my '97.
It sounds great, however my rear speakers are not working!!

I am using the two grey plugs.
I have disconnected the two plugs from the factory amp.

I had zero issues with the rear speakers prior to the install...

Any ideas??

Just had a similar problem. I installed new front door speakers and now my rear speakers aren't working.

 

[Whileemptyheadsdream]

It seems there Is always something that Is compromised when trying to get the perfect set up for our stereo's. I decided to run my alpine stereo/nav through the factory amp. Nothing Is broken and sounds o k, but Its not JBL premium sound. Good Luck !

 

[kruisinkid]

For the kenwoods and rear speakers. Its a setting in the menu. I forget which one. Buried in the menu

 

[NickPsy]

I'm a bit confused. I bought an Pioneer din unit (AVH 5700) and the Metra 70-8112 harness. For now, I plan on using the factory amp and speakers (which I'll eventually replace) so this is the harness that's supposed to work. I've looked at a bunch of threads and I can't seem to find any threads that show where the RCA plugs go. The color on the RCA plugs are white, green, purple and gray. The Pioneer has the matching color wires, with two strands of each color coming out of the harness. What goes where, or is the wrong Metra harness?

Thanks

 

[samiam09]

I just plugged the RCAs into the back of the stereo,They are already in the right position on the plug that connects to factory harness.But then I install a jvc unit.

 

[jeremy56]

I put in a new unit a few weeks ago and same thing, sounds bad and front door speakers don't work...

 

[rfakhrai]

I just installed the same HU in my '97.
It sounds great, however my rear speakers are not working!!

I am using the two grey plugs.
I have disconnected the two plugs from the factory amp.

I had zero issues with the rear speakers prior to the install...

Any ideas??

Same issue popped up for me after installing a new HU. I haven't gotten to the bottom of it yet, wondering if it's just some unintuitive setting on the HU that needs to be discovered.

 

[itechnology]

i am having the same issue u had understanding all of the various threads on how to bypass the amp ........ i have a 97 land cruiser 450 - did u end going from the head unit to the grey connectors? and then just unhook the amp? so in effect you didn't need to add 16 inches to the new toyota harness u bought?


could u possibly take a minute and explain again in more detail?

My factory stereo was seriously lacking in performance in my 1995 Land Cruiser so I decided to upgrade to a Kenwood DDX371 Touch screen unit. I purchased the Metra 70-8112 Harness to connect the new stereo harness to the factory harness (white connector) behind the stereo. I drove it for about a week in this configuration but the new sound wasn't what I was expecting, so off to Mud to find a solution! I read through many different threads saying to bypass or remove the factory amp in order to let the new stereo power the speakers. I decided that this was the solution to getting it to sound better. The threads stated that I needed to get a different harness other than the Metra 70-8112. This new harness was the Scosche TA02B. In most of the threads it stated that I needed to add 20" of wire to extend it from the back of the new stereo to the amp location near the passenger right knee. I can follow instruction good enough so that's exactly what I did, however once I routed this harness and tried to plug into the male connectors that came off the amp, it was a no go, they didn't fit! Off to Mud again to figure out where I went wrong. I noticed in a lot of the pics that some rigs have 3 connections at the amp where I only had 2. Could this be the difference between the Land Cruiser and the LX? I don't know but it didn't work. I stumbled upon a thread that said to connect this harness to the 2 gray (previously unused) connectors behind the stereo. It worked and sounded much better too! Problem solved! Hope this helps someone else.

I wanted to post this because I found some of the threads very confusing and in my case not accurate for my application. Over all I'm happy with the set up, however the screen does have a glare issue. Another odd thing, my front door speakers do not work in any of the configurations but the little dash ones do...not sure about that.


View attachment 876360
Another thing I was having problems with is the DVD player, it seems you have to hook up a wire for the Parking Brake switch in order to have it work. I just grounded it to the chassis of the stereo seems to work fine.



View attachment 876356
Metra 70-8112 harness used to connect the factory (white connector) to the new stereo utilizing the factory amp.




View attachment 876358
Schosche TA02B harness used to connect the 2 gray connectors to the new stereo in order to bypass or remove the factory amp.




View attachment 876362
Completed harness




View attachment 876363
2 connectors at the factory amp location




View attachment 876366
Connectors behind stereo. The 2 on the right are gray in color and the ones that I connected to. The white one is unused.




View attachment 876364
Stereo




View attachment 876372
Factory Amp removed