artwalk

Thank you for that, but as I do not wish to (as a novice mechanic) disturb the headliner etc, I need to find an alternative method. A garage once suggested to me that the only other way of clearing the rear drain lines, would be coming up from the bottom with a flexible cleaning rod, does that sound feasible to you?

Yes, I am the original owner which probably explains some of the non-longevity features of its appearance and its sound engineering condition. Thought of upgrading and/or changing to something else, but never saw anything that didn't put me behind the 8 - ball, either financially or lack of classy features. The vehicle cost AUD115,000 (USD107,500) in 1992, which is nthe equivalent of AUD191,000 in 2014. The current 2nd hand value of a good 1992 LS400 is between AUD7,000 and AUD9,000, and there isn't a vehicle that comes close to it for power and features. The current price for a 2014 LS460 is around AUD185,000 (USD196,000). Since I do fewer KM's now than I ever have (as you can see 105,000km in 22 years) there is absolutely no justification to change models. The is the odd dent and scratch , but the incredible '91 paintwork still looks like new after a wash and wax. Currentl sorting out a bit of a hiccup with the radio/amp, not a big deal. Will take some pics soon and post them.

Don't qualify for this one, but might well do at the other end of the scale for my 1991 LS400 (first reg'd March 1992) my reading is 105,000km, which is 65,500 miles. This enginec is just the same as the day I bought it in March 1992, 22 years ago, I kid you not. The interior is just like new, Have had a minor problem with the roof lining caused by blocked drain lines in sun-roof area. The lining is not spoilt, but cannot find anyone who knows how to clean out the rear drain lines, the front lines are asy by comparison. The only other problem I have EVER had, is the PS idler valve. This leaked for awhile causing a massive amount of smoke to be emitted on start up. Replaced idler valve but did not bother with connecting it back into the PS. PS feels NO different, even getting out of tight spots. Otherwise, this LS400 is like the day I drove it out of the showroom..

Landar - Did as you suggested - with the ignition on, I turned the radio switch on and off, both 10 and 20 times and the radio reacted accordingly each time, so it appears the switch is functioning as it should. Haven't been able to get to the trunk yet, so just to clarify before I start taking the lining out - looking into the trunk, the aerial is on the left, would that dictate the location of the amp, to be on that side too? The radio has always come on with the ignition, that is how it comes on randomly when everything warms up, its been doing this for the last 3 years with a consistent pattern of ambient warmth in conjunction with (I assume) some miles.It does not do this during the winter months.

One other point I didn't mention in response to your suggestion that it may be a worn on/off switch, is the fact that I have very rarely ever used the on/off switch in the 22 years I have owned it from new, The radio etc was always left on, so it was turned on and off with the ignition. I would have thought this was pretty common?

Thank you for that unput, but I've no doubt you know far more about Lexus than all of us put together. Your response, however, doesn't seem to address the ad hoc manner in which the radio only works during warm-to-hot weather, whereas your solution suggests the problem lies in the head unit and thus in the on/off switch. But what do I know? I'm more interested in locating the amp first and determining whether the connection points are corroded. Given that my '91 LS400 is in Australia and thus right-hand drive, would that mean that everything is opposite hand to a USA model? For example - the radio power aerial is on the passenger side of the trunk, which is the RH side looking directly at the car from the front. If I can locate the amp there as well, I may be able to solve the problem quickly and easily. If it's not fixable at the amp, then I can follow your suggestion, but not something I can do myself so remuctant to go there. It remains as to just where is the amp located?

I am searching for the correct location of the radio amplifier in a late '91 LS400. I was told once that it was located under the passenger seat, but this not the case. I need to locate it to solve a problem of the radio coming on when the weather is warm/hot, thus drying out what I was advised are probably coroded terminal connections, as the radio comes on of its own accord when the sulphur build-up dries out this permitting the connection to positively make live contact to the radio. Once contact is made the radio, both AM and PM work just fine. I'm not sure where else to look for this amplifier unit. Has anyone experienced this problem. Up until now the radio and CD player have worked superbly.

Thank you Pioneersuby for that input. I will get it checked out and let you know. BTW I have never noticed anything under the passenger seat (LH side of car) in the way of an electrical amp box, is that common on 1991 and 92 model LS400? My car was first registered in 92, but constructed in 91.

after years of good sound from both the radio and the cd player, both have recently stopped working. the radio is unusual in that it works sometimes, without any reason it just comes on and all station fm and am are received perfectly. however, the next time i get in the car there is no radio and it will not necessarily come on at all. has anyone experienced this sort of behaviour with a lexus ls400 radio?