mdfarme Posted July 14, 2004 Share Posted July 14, 2004 I have a '91 LS 400. Four of the warning lights in the dash have come on (radiator, battery, check engine, oil). I have replaced the battery and the problem persists. When I get up to a certain speed the warning lights all go out. When I slow down the lights come back on. Any thoughts? Quote Link to comment Share on other sites More sharing options...
VMF Posted July 14, 2004 Share Posted July 14, 2004 batery light means that the car is running on the battery power, not on alternator, and this basically means that ur alternator is dying and its time to change it. there is a slight chanse that itmight be a cirquit malfunction but 90% its the alternator. since you have a gen I ls check your power steering pump that is located right aboe the alternator if its leaking on the alternator or not. the rest of the lights are there coz ECU and all ECMs just dont get enuff juice to funcion properly. i bet you are gettin a pretty bad gas mileage. you can get a rebuilt alternator in almost any shop that does this kind of thing and it will run you around 250-300 with labor to fix it. while ure at it you might as well get a reman power steering pump which will cost u 100$ at autozone and around 50-70$ for labor and power steering flush. Quote Link to comment Share on other sites More sharing options...
90LS400Lexus Posted July 14, 2004 Share Posted July 14, 2004 I have heard that when the alternator shorts out- it will do this. Is any power steering fluid leaking onto the alternator? My old 81' Toyota Cressida did this, but it was a bad relay in the fuse block- a $2.00 replacement out of a junk yard, but I do not think these have this now. Quote Link to comment Share on other sites More sharing options...
90LS400Lexus Posted July 14, 2004 Share Posted July 14, 2004 Sorry- me and VMF must have been posting at the same time and he replied first.... disregard my post. I agree 100% with him. Quote Link to comment Share on other sites More sharing options...
mdfarme Posted July 14, 2004 Author Share Posted July 14, 2004 I had the car in the shop the last 2 days and they said the alternator was good, they were surprised by this but said it wasn't the problem, steering pump changed 2 months ago. Any thoughts related to the air conditioning? Quote Link to comment Share on other sites More sharing options...
VMF Posted July 14, 2004 Share Posted July 14, 2004 tell the shop check the V and A on the alternator when engine is idling, i still think its electrical prob. AC has nothing to do with it, AC shows AC related error codes on the climate control screen Quote Link to comment Share on other sites More sharing options...
mdfarme Posted July 14, 2004 Author Share Posted July 14, 2004 The shop that had my car believes that something was draining the battery, their explanation was the circuit for these censors had the anti theft recovery and that it had a short somewhere in the wiring, so they disconnected it, I haven't used the theft recovery on the car in three years, 250.00 later the same issues are there as when I brought the car in. Do you have any idea on the time it would take to check everything attached to that one circuit, I think I'm in theposition where I'm starting over at a new location tomorrow and don't want to go through all the same checks over again, I'll definitely start with the alternator but from there............. Quote Link to comment Share on other sites More sharing options...
VMF Posted July 14, 2004 Share Posted July 14, 2004 there is a cirquit that controls the alternator and it might be malfuncioning as well and not giving enuff juice for the electronics. try this, when the car is parked rev the engine at 2500-3000 rpm for like a minute and check if lights will go off. if they will it means you just dont have enuff power from alternator. Quote Link to comment Share on other sites More sharing options...
mdfarme Posted July 15, 2004 Author Share Posted July 15, 2004 Update, replaced the alternator yesterday, tested fine on Tuesday, asked for it to be retested Wednesday morning and it was bad, so replaced it, put in a new battery and disconnected the add on theft recovery which seemed to be what was the draw on the dome fuse. Thanks for the info. Quote Link to comment Share on other sites More sharing options...
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