Sound Only From Left Rear Speaker?

[BigJo]

I have a '93 LS400 with a Nac system and only get sound from left rear speaker... my car has a factory (I think) phone cradle in the arm rest, somewhere it seems there was a reference to the phone audio coming over the left rear speaker, so I am wondering if maybe there is something messed up with the phone/stereo? is there a slick fix that anyone can think of?

[1990LS400]

If the phone cradle is from a dealer installed Lexus phone system, there should be a control module for it on the left side of the steering wheel unless it has been removed. The control module has three buttons and a lever. If there is no steering wheel phone control, there will be a removable plastic blank. Does the phone cradle have any brand marking?

From what I remember, the old Lexus phone systems played the phone call audio only through the left rear phone system. If you are getting radio audio through only your left rear speaker, I suspect there is some other problem.

Is this a new problem? (i.e. were all the speakers previously working?)

[mejojo]

I have a '93 LS400 with a Nac system and only get sound from left rear speaker... my car has a factory (I think) phone cradle in the arm rest, somewhere it seems there was a reference to the phone audio coming over the left rear speaker, so I am wondering if maybe there is something messed up with the phone/stereo? is there a slick fix that anyone can think of?

When you say "only get sound from left rear speaker", does that really mean no woofer, no right side, no nothing? Or are you saying that you can't hear anything from the left front?

I recently had to replace the 2 (front & back) left door speakers in my '92 that has the Nakamichi system.

Joe

[BigJo]

This is not a new problem, just one that has been on my "To-Do" list for a couple of years, I bought the car a few years back and the stereo has never came over all the speakers, including the sub, I only get audio over left rear, and there is no phone control on the steering wheel or to the side on the dash... The cradle is a Motorola... any other ideas?

[1990LS400]

Well, then ... it sounds like the cradle is for an aftermarket phone kit. Even when a phone kit, Lexus or otherwise, is hooked up to mute the radio during a call, it would mute all the speakers and not just some of them.

You might want to take a look at http://carstereohelp.com/lexus.htm They offer advice on what to check to determine the problem.

These are the guys that fixed the Nak head unit in my 00 LS earlier this year. I was lucky to have a friend with an identical car so I was able to determine which component was the problem by swapping mine into his car.

If you have to have your head unit or amp repaired, I would highly recommend Car Stereo Help. They were quick, cheap and nice too.

[azpir8king]

I have a '93 LS400 with a Nac system and only get sound from left rear speaker... my car has a factory (I think) phone cradle in the arm rest, somewhere it seems there was a reference to the phone audio coming over the left rear speaker, so I am wondering if maybe there is something messed up with the phone/stereo? is there a slick fix that anyone can think of?

B) I apologize for jumping in here, but....

I have a 1991 Lexus ls400. I do have the original phone and the buttion bank. My left rear speaker is the only one working. I have heard of a fix where you can go to the phone interface mudule and disconnect the two plugs and connect them together, bypassing the module-mute. Any ideas on how to do this (location of module,etc) or if there is another stock fix for this? I actually hooked a 10 watt amp across the woofer in the rear and got it to play, so its definately an interface or connect issue

[1990LS400]

I have a 1991 Lexus ls400. I do have the original phone and the buttion bank. My left rear speaker is the only one working. I have heard of a fix where you can go to the phone interface mudule and disconnect the two plugs and connect them together, bypassing the module-mute. Any ideas on how to do this (location of module,etc) or if there is another stock fix for this? I actually hooked a 10 watt amp across the woofer in the rear and got it to play, so its definately an interface or connect issue

I may have been the one who posted information you read on disconnecting the two large connectors from the trunk mounted phone ECU on a 98-00 LS400 and plugging them together to bypass the ECU and complete the circuit. I do not know if this applies to the earlier LS400. As I just posted on another thread, I think the phone ECU in a gen 1 LS400 is behind the left side trunk trim -- only because that is where the dealer had a phone ECU for a non-Lexus phone system installed when I bought my first LS400 in 1990.

If there are two of you -- one with a 93 LS and one with a 91 LS -- who have dealer installed Lexus phones and only the left rear speaker working, then "the plot thickens".

I vaguely remember someone posting specific instructions about removing the phone from a gen 1 LS400 but I'd be hard pressed to find the thread. I think it was at least a year ago and I'm not even sure it was on this Lexus forum. I'll see if I can find the thread.

[1990LS400]

This diagram for a 90 LS suggests that the phone ECU is on the right side of the truck of a gen 1 LS400: http://www.lextreme.com/Lexradio.pdf

I've done quite a bit of searching this morning for that past thread about a Lexus phone problem muting all the speakers except the left rear. In all the related threads I've found, the problem mutes all the speakers.

[1990LS400]

Darned, here's a thread that says the Lexus phone in the 93 LS was installed on the driver's side of the trunk: http://us.lexusownersclub.com/forums/index...20&hl=phone

[azpir8king]

Darned, here's a thread that says the Lexus phone in the 93 LS was installed on the driver's side of the trunk: http://us.lexusownersclub.com/forums/index...20&hl=phone

Thanks for the replies. Since it was fifty-fifty based on the replies, I completely dissected my 1991 LS400 trunk last night. On the passenger side is the Suspension ECU, which you have to completely remove from its mounting to read the sticker on the side that tells you its that module and you are looking in the wrong place, then re-install it.

So the phone was on the drivers side (actually had my hands on it the day while putting my new antenna drive in). There were two connectors (one leading to and one from) I disconnected them from the unit, sprayed in some contact cleaner, and then connected the two together bypassing the phone ECU (and its mute). The speakers all played but a severely reduce volume (except the right rear passenger which continued at normal volume). Next step is to look at the amp and the link connections under the passenger seat. Any other suggestions?