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Ask Don 'Mo Lurch' Your Own Que...
Don 'Mo Lurch'
Don 'Mo Lurch', Car Electronics Technician
Category: Car Electronics
Satisfied Customers: 20897
Experience:  over 30 years, ARA, Sony, Alpine, Audiovox, Kenwood, Muntz. Sales, Repair & Installation
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Toyota JZX100 amp wiring
, I have an aftermarket stereo

Customer Question

Customer: ***** ***** - Toyota JZX100 chaser amp wiring
JA: Thanks. Can you give me any more details about your issue?
Customer: I have an aftermarket stereo and the car comes with the factory amp. Ive got a harness adapter for a toyota with an amp that uses RCA pre outs from the head unit to go to the factory amp. This should all be good. Initially i wasnt sending a switched live to the amp to turn it on so got no audio. When i did connect this it seemed to work. Then with no changes when i restarted it didnt work again. Then i took it out unpluigged and replugged found no problems and it worked. And now it doesnt work again. Slightly confusing i know. The stereo works fine and is outputting audio from what i can tell. But the speakers are either silent, or work fine. They dont come in and out. I have checked that i am sending a switched 12v down what is i think a red/blue wire on the chaser, to turn the amp on. But i still get nothing Thats where i am now stuck
JA: OK got it. Last thing — JustAnswer charges a fee (generally around $18) to post your type of question to Car Electronics Experts (you only pay if satisfied). There are a couple customers ahead of you. Are you willing to wait a bit?
Customer: Yeah, if it fixes my problem im happy to pay a few bucks. Even if i can confirm 100% that maybe the amp is dead that suits me.
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Submitted: 1 year ago.
Category: Car Electronics
Expert:  Don 'Mo Lurch' replied 1 year ago.

please post:
Brand & Model Number of Radio that you installed

Customer: replied 1 year ago.
Kenwood DDX-4015DAB
Customer: replied 1 year ago.
Please see image of adapter, ill get the part number for that in a bit
Expert:  Don 'Mo Lurch' replied 1 year ago.

Adapter is fine.........
When the issue of No sound happens, please verify Voltage + on the BLUE / WHITE wire of the Kenwood
IF there is Voltage + then check PIN alignment inside Plug Adapter to be sure they are aligned
IF NO Voltage + then the AMP could be needing more Voltage / amps to Turn On & stay On, which the BLUE / WHITE wire only supplies apprx 2 amps
Disconnect the BLUE / WHITE wire & connect a jumper from the RED wire of the Kenwood to the AMP Turn On
Let me know what you find

Customer: replied 1 year ago.
Sure. I'll touch the wire on so it effectively becomes a switched live. I'm guessing that has a higher current capability. Thanks for the help. Will check and let you know.
Expert:  Don 'Mo Lurch' replied 1 year ago.


Be sure to disconnect the BLUE / WHITE wire prior to connecting Voltage +, so you do not "back feed" into the Kenwood


Customer: replied 1 year ago.
Hi there. Sitting in the car now. I checked and I was getting switched 12v but the result was as before.
I confirmed the blue white wire of the adapter goes to the red blue in the car.
I then jumped the blue white wire of the harness onto the red of the harness/head unit. Interesting result. Gives a kind of quiet thud through the speakers (all of them) but no actual audio
Expert:  Don 'Mo Lurch' replied 1 year ago.

IF you have the AMP connected correctly, I would disconnect the RCA's, then reconnect the AMP Power wire & be sure there is a GOOD Ground to the AMP
Then with Unit ON, connect the RCA's "one at a time"
Bad Speaker can cause this issue & or the AMP is bad

Customer: replied 1 year ago.
Thank you. I will have to check this tomorrow evening. Will let you know.The speakers did work a couple times so I think the basic amp wiring is ok. Earth could be faulty or speakers. Should I do speakers one at a time or systematically add them?
Customer: replied 1 year ago.
I connected each speaker RCA separately and had the same characteristic. Have to take my seat out to get at the amp wiring so will check that tomorrow. Do you have access to the amp wiring diagram? It's a 1998.
Expert:  Don 'Mo Lurch' replied 1 year ago.

sorry........I do not have the wiring for that year.......
It appears that if there is Voltage + to the ON of the AMP, & then the AMP loses sound, there is an issue with the AMP or Speakers, which would also cause same issue if one or more speakers are shorted

Customer: replied 1 year ago.
Would that explain that a couple of times I had it working? I didn't change anything in between and it worked the whole time the stereo was on. Then when the ignition was turned off and on or a couple bits were unplugged it just didn't work. It's never cut in or out whilst the stereo was on.
Expert:  Don 'Mo Lurch' replied 1 year ago.

was the last unit that was in there doing the same thing?

why was this Kenwood installed?

Customer: replied 1 year ago.
I upgraded it. The Japanese unit that was in there was quite old, it also didn't work but I can't confirm the unit itself worked as it wouldn't accept a CD or go to a radio station.
Expert:  Don 'Mo Lurch' replied 1 year ago.

did it have sound (static) on all speakers?

Customer: replied 1 year ago.
No there was just nothing. The whole system was dead. I think that may have been the unit though. I've only had it working with the new head unit. It worked the very first time I connected the blue and white switched live to the amp on signal. Then I took it apart and crimped it all up and fitted it properly (it had been in the footwell) and it stopped working. Then I took it out to see if the wire had uncrimped but it hadn't. So I just pushed it all back in as it was late and it decided to work again. But since then I've had nothing. Sorry for the long story!
Expert:  Don 'Mo Lurch' replied 1 year ago.

no to know as much as possible........
I am still thinking AMP or Speakers, as you have connected direct voltage to the AMP Turn ON wire, & the sound works, then goes out
Problem with the older stuff is there are Capacitors that "leak" over time & can cause the issue.
It would be more labor, but disconnecting Speakers & connecting one at a time could help pinpoint the issue

Customer: replied 1 year ago.
I've heard of leaky caps in ECUs, will see if it's easy to open the amp. It was only a bit of a noise when conne ring and disconnecting the direct power. My plan was to run an extra speaker cable from the normal head unit outputs to the speaker wire at the amp. Should be an easy enough test, then the speakers can be eliminated. Only leaves the amp or associated wiring.
Expert:  Don 'Mo Lurch' replied 1 year ago.

sorry for the delay..........No Internet

correct........... you should be able to pinpoint that way also

Customer: replied 1 year ago.
No worries. I think i am stuck for a while now with the holiday season so wont be able to look until the new year. Will you still be available to assist?
Anyway, thanks very much for the help so far, have a great Christmas and Ill give you an update as soon as i can.Cheers
Expert:  Don 'Mo Lurch' replied 1 year ago.

no problem..........I am on "typically" everyday & will respond when I see any replies.........
IF this times out, just start a new one with a request for me
thank you

Merry Christmas.....................

Customer: replied 1 year ago.
Ah, will it time out? I might just drop in a generic message every few days to ensure it doesnt. Otherwise, as you say, ill just request you again. Cheers!
Expert:  Don 'Mo Lurch' replied 1 year ago.

not a problem


Customer: replied 1 year ago.
Hi Don, hope you had a good christmas. Should be able to hard wire the speakers this weekend so will give you some feedback when i do that. Cheers
Expert:  Don 'Mo Lurch' replied 1 year ago.

sounds good............let me know what you find


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