Bizarre Radio

[90LS400Lexus]

My radio acted bizarre again this morning. It did this back in the winter as well, but this is the only two times it has occured. This morning, I got in the car, started it and pressed the radio "on" knob. Nothing happened. I tried this at least 15 times- nothing. I gave up, livid of course and drove on. About 5 minutes down the road- I pushed the button again- and presto- the radio instantly came on- perfect sound as ever. My question is- what is happening here? Another strange thing is that the radio was "on" when I turned the car off last night- so it should have automatically came on this morning- which puzzles me why it would not. I usually leave it on and when I restart the car the next morning, it automatically comes on. Any suggestions? Thanks in advance.

[VMF]

there are 2 known causes for this, there eithere a loose wire inside the head unit or in the connectors somewhere, or there is a shortage and there is a cirquit insde that will turn the unit of in case of overload.

the 3rd case is the voltage in the car is below minimum on idle and it is not enuff for the radio.

[90LS400Lexus]

Thanks VMF.

Just my luck- more problems- <_< now I am sure am selling this car before something else happens. Strange that it has only done this twice within 9 months and only does not come on when I first start the car of the morning.

About the voltage- as far as I know - that seems fine, as all of the lights are bright and everything else operates as normal- even when I first start it. Back in the winter when it done it- at came on after I pressed it about 20 times, but only after I had been driving for about 2 minutes or so.

Also wondering if it is an electrical short in the wiring, or a loose connection- why does it not cut on and off through the day- especially when I hit a bump? Once it comes on- it is on- no cutting out.

I am leaving on a small 2-day trip tomorrow, so I take it apart and see what is wrong when I return.

Thanks again.

[90LS400Lexus]

Well, I am back from my short, 2-day trip......

I have another question about the radio- it is again working fine. I am wondering- could it possibly be the actual switch to the radio? That is what I was initially thinking, but thought if it was- odd that it would come on after a few minutes of driving. I was also thinking the same thing that VMF said, but I cannot understand why it would be working fine the night before- turn the car off and then when I restart the car the next morning- it is dead for a few minutes and the radio does not cut off at all after it comes on. I was thinking if it was a bad connection, shouldn't it also cut off when I hit bumps or something? Thanks again.

[VMF]

its a lil tricky with those modern electronics, you should consider temperature, humidity and other stuff when looking for the problem. it might even be a problem in one of the microchips on one of the cirquit boards.

[90LS400Lexus]

Thanks for the additional information. I would bet it is something wrong with the actual radio. As mentioned, until two days ago, the last (and only) time it done it was back in the winter. January I think it was- it was cold- with temperatures in the upper 40s if I recall correctly. I was assuming it was just the radio "did not like" the cold weather. :P When it did it the other day, it was in the 80s at 11AM- so I do not think the temperature is a factor- but what do I know? Humidity- it was high- as it typically is here year round'. Perhaps it is nothing major- it has only happened twice within several months, so it is not too big of a deal, but I was just wondering why it is doing this bizarre behavior. Thanks again.

[vyhanh]

Perhaps, you may try checking the trunk? Maybe the problem of short wiring in the trunk lever may cause this? My 2c's

[90LS400Lexus]

Thanks. How do I check (or gain access to) that electrical wiring? I have not been having any problems with my instrument panel lighting, so I never thought of that. It did do it again this morning, but I took more notice of what it is doing. When I press "ON", the green light on the radio will come on for about a second and I can hear the power antenna make a click noise, then the radio will go back off. It did this about 6 times this morning, but it finally came on. Could it also possibly be a problem with the antenna? It has recently broken- meaning that it will not go back down, unless I initially "help" it to retract down- then it will go down under its own power. Thanks again!!!

[90LS400Lexus]

Thanks. How do I check (or gain access to) that electrical wiring? I have not been having any problems with my instrument panel lighting, so I never thought of that. It did do it again this morning, but I took more notice of what it is doing. When I press "ON", the green light on the radio will come on for about a second and I can hear the power antenna make a click noise, then the radio will go back off. It did this about 6 times this morning, but it finally came on. Could it also possibly be a problem with the antenna? It has recently broken- meaning that it will not go back down, unless I initially "help" it to retract down- then it will go down under its own power. Thanks again!!!

OK to update- I was able to see the wiring harness I have been hearing about inside the trunk on the left side. I see a bundle of wiring going inside of the rear firewall (if you will), as well as some wiring on the trunk hinge. It all appears to be OK, but if it was that wiring, is it something I could see just be looking at it? Please forgive my ignorance.

[vyhanh]

If the wires look ok, I think that the radio problem may have been caused by the faulty antenna (which is common in the LS). Good luck!

By the way, your other thread about the manuals: I think the manuals are the real thing not the CD

[90LS400Lexus]

If the wires look ok, I think that the radio problem may have been caused by the faulty antenna (which is common in the LS). Good luck!

By the way, your other thread about the manuals: I think the manuals are the real thing not the CD

Thanks.

About the manuals- you must have me confused with someone else, because I did not ask about those. Perhaps they will read your reply.

[90LS400Lexus]

Well, the radio did it again this morning. After I drove away, it came on. Perhaps VMF has something there and it is that the radio is not getting enough power at startup. If it does it tomorrow- I will "race" up the engine and get the RPMs higher and see if that allows it to come on sooner.

This car is really starting to frustrate me.

[90LS400Lexus]

Well, it did it again this morning. Seems to be an everyday thing now. I raced the engine to about 2500 rpms and no change. Still would not come on. I waited about 30 seconds, backed down the drive and presto- it came on. Very strange. I do not think it is a short now, because if this was the case, I would think it would also do it throughout the day, or cut on and of when driving- which it does not. Once it finally comes on in the morning- it is fine the rest of the day. Puzzling.

[90LS400Lexus]

Well, it has done it again. It is a everyday thing now, but I know something new now: it is not a short or a loose connection. This morning- again it would not come on, but I decided to hit the "eject" button and the cassette came out. I pressed it back it- it took it back in. I hit eject again and it came back out. Tried the radio- still would not come on. Ejected tape again- pushed it in again and then the cassette started playing. Then turned the cassette off- switched to radio and it worked fine. So... obviously- even thought it is not coming on (radio) it is getting power, since the cassette eject buttom (and cassette motor) is working- unless they are on a totally different circuit- which I doubt? I am concerned that one day it will decide it is not coming back on - never.

BTW- I took a glance in the wiring in the trunk- by the hinge and it looks like new, so I am assuming all there is fine. All other lights and intruments still work fine. it is like the radio has to electronically "warm" itself up before it will work. No matter how hot it is in the car- the first time in the day- it takes several attempts to come on. I think tomorrow I will not touch it and see if it comes on automatically after I hit the road.

[vyhanh]

Checked my workshop manual about the radio: Since the cassette player was playing and then when ejected, the radio played, it seems that (according to the manual diasnostic steps) the fault can be with either the radio assembly or the antenna system.

[90LS400Lexus]

Thanks for checking that for me. Actually, the cassette was not playing, but actually the cassette that was already in there would eject when I hit the button, but when I pressed it back in, the radio (or cassette) would not power up. It was like the cassette eject button and the "motor" that puts the tape in and out is all that was working. For the first time in a week- the radio came on first time this

morning when I pressed the button.

[90LS400Lexus]

OK. It was a little darker out this morning when I left for work. I noticed when i pushed the power button, the green light in the radio would initially light up, but go back out. It did this everytime, until it finally came on. Strange.

Oh well.... its bedtime.

[90LS400Lexus]

To further update- it seems to be sensitive to the temperature. This morning it was a cooler- well about the coolest mornings we have had in a while- the low was 60 degrees. When I left for work at 9:40, it was about 66 outside. This time, the radio never came on at all- even when I got to work. I went to lunch at 2:00- it was about 87 outside- so at least 100 in the car- and presto- the radio came on instantly. So whatever it is, it varies by the temperature. I guess that the radio is simply going bad.

[90LS400Lexus]

I mentioned it to my father and he said it was probably a cracked circuit board in the radio. When it warms up, the board expands- hence the radio working again. Possibility?