'00 RX300 no volume
#17
Don't know if this helps but attached is an audio system wiring diagram for a 2000 RX300.
An issue, apparently rare, that can cause the audio system to mute is if the "tele-mute" wire (labeled TMUT on the diagram) becomes permanently grounded. Based on what I have read on this and other Lexus forums, this problem is more likely to arise if the car has or had a dealer installed Lexus phone system. The problem can be caused by a defect in the phone system even if it is no longer used or if the phone system has been removed by cutting wires rather than unplugging the connectors on the factory installed phone harness to the dealer installed phone system components. I saw one thread about the TMUT wire getting grounded from corosion caused by water getting to the connections on the amp.
That said, I think it more likely a problem with your amp or headunit.
It might be worthwhile to have a technician evaluate the problem. The tech at my local indie Lexus repair shop seems to be able to debug audio system problems - at least to the extent of determining which component is causing the problem so they can send it out for repairs.
An issue, apparently rare, that can cause the audio system to mute is if the "tele-mute" wire (labeled TMUT on the diagram) becomes permanently grounded. Based on what I have read on this and other Lexus forums, this problem is more likely to arise if the car has or had a dealer installed Lexus phone system. The problem can be caused by a defect in the phone system even if it is no longer used or if the phone system has been removed by cutting wires rather than unplugging the connectors on the factory installed phone harness to the dealer installed phone system components. I saw one thread about the TMUT wire getting grounded from corosion caused by water getting to the connections on the amp.
That said, I think it more likely a problem with your amp or headunit.
It might be worthwhile to have a technician evaluate the problem. The tech at my local indie Lexus repair shop seems to be able to debug audio system problems - at least to the extent of determining which component is causing the problem so they can send it out for repairs.
Thx - Russ
#18
Russ,
The 2003 RX300 audio system diagram (no nav) from ARRC shows a telephone mute connection. See the attachment.
The CPO model library shows that the following option was available on the 2003 RX: "Lexus Mobile Phone with Command Module and audio muting". You can read the full text here: http://www.lexus.com/cpo/model_library/RX/2003.html
I remember seeing a thread on this forum a long time ago where someone found a mute connection on his 99 RX (I think) towards the back of his car.
I don't know much about how the Lexus phone systems work on 2001-2003 Lexus vehicles. The phone systems used in Lexus vehicles kept changing. On many 95-00 Lexus vehicles like my 00 LS400, there is a factory installed phone connector (meant to be used with the dealer installed phone) under the center console that has a mute pin. On my car, the mute pin is the center/front pin on the six pin handset connector on the drivers side of the car. On an 95-00 LS400, it requires some minor disassembly of the center console to get to this connector. On my car, there is also a mute pin on the large connectors meant to be plugged into the phone ECU in the trunk.
One can find a mute pin by carefully probing with a unpowered 12V grounded test light while the radio is playing. When you touch the mute pin with the test light, the radio will mute. Be careful when doing this or you could do damage.
I'll try to watch this thread so you might want to PM me if you want more input.
The 2003 RX300 audio system diagram (no nav) from ARRC shows a telephone mute connection. See the attachment.
The CPO model library shows that the following option was available on the 2003 RX: "Lexus Mobile Phone with Command Module and audio muting". You can read the full text here: http://www.lexus.com/cpo/model_library/RX/2003.html
I remember seeing a thread on this forum a long time ago where someone found a mute connection on his 99 RX (I think) towards the back of his car.
I don't know much about how the Lexus phone systems work on 2001-2003 Lexus vehicles. The phone systems used in Lexus vehicles kept changing. On many 95-00 Lexus vehicles like my 00 LS400, there is a factory installed phone connector (meant to be used with the dealer installed phone) under the center console that has a mute pin. On my car, the mute pin is the center/front pin on the six pin handset connector on the drivers side of the car. On an 95-00 LS400, it requires some minor disassembly of the center console to get to this connector. On my car, there is also a mute pin on the large connectors meant to be plugged into the phone ECU in the trunk.
One can find a mute pin by carefully probing with a unpowered 12V grounded test light while the radio is playing. When you touch the mute pin with the test light, the radio will mute. Be careful when doing this or you could do damage.
I'll try to watch this thread so you might want to PM me if you want more input.
#19
Jim,
Thanks for the diagram and the tips. So I gather I should pull apart the center console and look for wiring for the phone option and look for the violet wire in that. Then if I ground that wire (through a test lamp you recommend) the radio would mute. From the diagram it looks like the only other wires in that connector/area would be the black and yellow for feeding the left rear door speaker. So if I wanted to tap that speaker for my Parrot bluetooth interface that would be the place to do it. Seems weird to have the phone audio coming from behind the driver. I'll see what I find and report back.
Russ
Thanks for the diagram and the tips. So I gather I should pull apart the center console and look for wiring for the phone option and look for the violet wire in that. Then if I ground that wire (through a test lamp you recommend) the radio would mute. From the diagram it looks like the only other wires in that connector/area would be the black and yellow for feeding the left rear door speaker. So if I wanted to tap that speaker for my Parrot bluetooth interface that would be the place to do it. Seems weird to have the phone audio coming from behind the driver. I'll see what I find and report back.
Russ
#20
RX300Russ,
I have mentioned how the under console phone connector works a number of times on the 95-00 Lexus cars but I don't remember anyone reporting if the 2001-2003 cars have a similar connector. I hope you find something.
I did not look for a speaker connection in an under console connector. It is possible that one is there but it also could be at the rear of the car phone where the dealer installed Lexus phone ECU would live. jainla over on us.lexusownersclub.com ran his Bluetooth audio through a door speaker of his 2001 LS430 but I think he had to connect the phone kit's speaker wire to a connector in the factory phone wiring harness in the trunk. But who knows what you will find. Nothing ventured, nothing gained.
Parrot sells a speaker that can be used so you don't have to tap into the cars door speaker wires -- definitely easier to just mount an external speaker under the dash and be done with it. We have external speakers for our phone kits in both our 00 LS and 98 Camry and the sound is great.
Before Parrot came out with an external speaker, people used various brands of phone kit speakers including ones from Nokia - very cheap and you might even find an old one for free from a phone installer. The newer Nokia speakers are a bit smaller than the one in the attached photo of the speaker installed under the dash of my 00 LS.
I have mentioned how the under console phone connector works a number of times on the 95-00 Lexus cars but I don't remember anyone reporting if the 2001-2003 cars have a similar connector. I hope you find something.
I did not look for a speaker connection in an under console connector. It is possible that one is there but it also could be at the rear of the car phone where the dealer installed Lexus phone ECU would live. jainla over on us.lexusownersclub.com ran his Bluetooth audio through a door speaker of his 2001 LS430 but I think he had to connect the phone kit's speaker wire to a connector in the factory phone wiring harness in the trunk. But who knows what you will find. Nothing ventured, nothing gained.
Parrot sells a speaker that can be used so you don't have to tap into the cars door speaker wires -- definitely easier to just mount an external speaker under the dash and be done with it. We have external speakers for our phone kits in both our 00 LS and 98 Camry and the sound is great.
Before Parrot came out with an external speaker, people used various brands of phone kit speakers including ones from Nokia - very cheap and you might even find an old one for free from a phone installer. The newer Nokia speakers are a bit smaller than the one in the attached photo of the speaker installed under the dash of my 00 LS.
Last edited by Kansas; 04-18-08 at 06:49 AM.
#21
wiring harness
does anyone have any referrals to where I can get a new wiring harness for the stock amplifier in a '01 rx300.
i have been having issues with sound quality and the sub not working and have traced it back to the amplifier and really bad after market installation.
apparently the individual who had it prior to me did this themselves and upon putting original stuff back, they forgot the adapter that wires to the subwoofer and back right passenger speakers so its offset.
its so hard trying to find the harness that plugs INTO the amplifier.
amplifier is a pioneer GM-8706ZT
i have been having issues with sound quality and the sub not working and have traced it back to the amplifier and really bad after market installation.
apparently the individual who had it prior to me did this themselves and upon putting original stuff back, they forgot the adapter that wires to the subwoofer and back right passenger speakers so its offset.
its so hard trying to find the harness that plugs INTO the amplifier.
amplifier is a pioneer GM-8706ZT
#22
KATSRX300: did the previous owner cut the factory connector off of the wiring harness to connect their aftermarket amp? And then they reinstalled the factory amp and didn't connect these wires? If that is the case, I am afraid I don't know where you can get the plastic plug with wires to attach to your chopped up harness. A junkyard would probably be your best bet.
Russ
Russ
#24
#25
I fixed this same issue on our 99 RX300. It turned out to be the tmut short. From the wiring diagram I cut the “tmut” wire. The only part of the radio system I could find was the amplifier behind the back seat. Anyway the connectors were the same but some of the wires were not there. I found the one for “tmut” cut it and put the thing back together. To my delight, this worked and the sound came back.
#27
Never mind...I pulled the amp last night and performed the TMUTectomy on it. Still no sound. The problem started when I cleaned the MAF sensor. I didn't dry it off well enough and it caused a series of shorts. The whole car was going haywire...literally! Everything is back to normal except the radio. As prior posters have said...everything works with the exception of the Bass Mid Treb stuck at 0 and the minor detal of no sound from the speakers. Where is the head unit in a '99RX300. That is my next step.
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