akataz Posted October 12, 2004 Share Posted October 12, 2004 Guys, I was driving my 1990 LS400 normally to work this morning on the highway and all of a sudden the following lights came on at once: - Battery - Coolant - Oil Pressure - Taillights - Brake (parking) The car feels and runs normally as far as I can tell. I was a mile away from my exit and was able to make it to work without a problem. It's still dark outside so I did not pop my hood. Has anyone had this happen to them? Any idea of what it means? :cries: Thanks, The Taz Quote Link to comment Share on other sites More sharing options...
1991LS400 Posted October 12, 2004 Share Posted October 12, 2004 Hey, Got a 91 LS 400. I just had that happen to me a few days ago but it wasn't all the lights you listed. I'm not due for another oil change but my oil pressure light will come on and then go off, come on, and then go off. There is absolutely nothing wrong with my oil, pan, gasket, pressure, or anything. I'm going to get my oil changed today to see if it does it again. Your problem sounds like something's going on with your instrument cluster board and you might need to get it fixed. My speedometer and gas gauge are broken and don't read accurately at all so I'm taking it in to a speedomoter shop to get it fixed. DO NOT go to the dealer if you can help it. Brian Quote Link to comment Share on other sites More sharing options...
GSsoldier Posted October 12, 2004 Share Posted October 12, 2004 it seems there problems with wiring, your LS is a first gen, wiring seems to be a problem with the first gens too, something got loose, or shorted, or not complete connections Quote Link to comment Share on other sites More sharing options...
Thienn Posted October 12, 2004 Share Posted October 12, 2004 I agree with GSsoldier! Check your wires for short, damage or even loose ground connection. I also had problem with my SC400 tail and brake light due to ground. You might have to take cluster out and do a thrurought inspection! Good Luck Quote Link to comment Share on other sites More sharing options...
VMF Posted October 12, 2004 Share Posted October 12, 2004 it happend to my friend with GEN I LS and it turned out to be a dead alretnator, everything switched to the battery and once battery is starting to loose the juice you will get all these warning lights since the devices in the car just dont have enuff power to operat and will signal a malfunction. have your alternator checked. Quote Link to comment Share on other sites More sharing options...
Thienn Posted October 12, 2004 Share Posted October 12, 2004 Try this test to see and see if the alternator is bad! Start the car and disconnect the battery (possitive terminal) while it is running. If the car stalls then the alternator went bad. If not, look somewhere else! Good Luck. Quote Link to comment Share on other sites More sharing options...
akataz Posted October 12, 2004 Author Share Posted October 12, 2004 Thanks for all the feedback guys. Me and a couple of friends went and looked at the car and nothing seemed to be wrong. We even disconnected the negative terminal from the battery and let it sit for an hour, in case it was just something with a computer that needed to reset itself. No luck. I have an appointment with the dealership in about an hour. I'll let you guys know what it turns out to be. Thanks! Quote Link to comment Share on other sites More sharing options...
90LS400Lexus Posted October 13, 2004 Share Posted October 13, 2004 This has been discussed several times in the past and it seems to be linked to a faulty alternator. May want to run a "search" here on "LOC". Possibly your PS pump is leaking oil into the unit and shorting it out. ??? Good luck. Keep us posted. Quote Link to comment Share on other sites More sharing options...
spiller91ls Posted October 13, 2004 Share Posted October 13, 2004 Your alternator is bad and you'll need to replace it. Don't disconnect your + battery lead with the engine running, that's is a bad thing to do to a modern car, and all you will do it put a high voltage spike on your electrical system when you put the lead back onto the battery. What that mainly does is blowes out the diodes in the rectifier/regulator, and all a alternator is a 120 volt A/C genorator that has a rectifier/regulator that converts it down to 12 volts D/C. Don't do it. Quote Link to comment Share on other sites More sharing options...
VMF Posted October 13, 2004 Share Posted October 13, 2004 DO NOT and i repeat DO NOT follow that advice and disconnect the battery while your engine is running!!!! you are risking of frying your ECU and bunch of ECMs!!!! NEVER EVER do this!!! there is a special tool to check your alternator, just go to the shop and ask them to check it for you! Quote Link to comment Share on other sites More sharing options...
90LS400Lexus Posted October 14, 2004 Share Posted October 14, 2004 NO NO- do not disconnect that battery cable with the engine running. VMF is right- it will cause severe damage. Quote Link to comment Share on other sites More sharing options...
akataz Posted October 21, 2004 Author Share Posted October 21, 2004 Guys thanks for all your help. It turned out to be the alternator after all. It ended up costing me about $500 to have the dealer replace it. The alternator was $326 and 1.5 hours of labor was about $160. I looked online after I had gotten it repaired to see what an alternator would cost for that car, since it seemed a bit steep. It was $300 from various online parts stores, so I don't feel bad at all that it cost me $326 from the dealer. Again thanks for everybody's input. Great site! Keep it up! Quote Link to comment Share on other sites More sharing options...
spiller91ls Posted October 21, 2004 Share Posted October 21, 2004 I paid $150 from checker auto for mine, did my own work Quote Link to comment Share on other sites More sharing options...
90LS400Lexus Posted October 22, 2004 Share Posted October 22, 2004 The symptoms seem to be the same for all Toyota products. When the alternator went out on my old 1981 Toyota Cressida (the Lexus LS of the late 70s and 1980s) also did this when the alternator went bad. The "volts" guage would show "discharge" and the lights would illuminate. It happened again, but it was not the alternator. After taking it to one of the Toyota dealerships, I found out that it was a faulty relay in the fuse block. It was $80. from the dealer, but I got one at a local salvage yard for $2.00 out of a 82' Toyota Celica. :D When it went bad, the following lights would illuminate: "low fuel, battery, oil, oxygen sensor, fasten lap belts, brake, radiator, low washer fluid, door ajar, etc. Quote Link to comment Share on other sites More sharing options...
spiller91ls Posted October 22, 2004 Share Posted October 22, 2004 when my alternator had gone bad last year I had gone over the print for the instument wiring, and had found that toyota/lexus has put 3 diodes on backwards, I not even sure why they make that part of the wiring too complicated. Quote Link to comment Share on other sites More sharing options...
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