hi what do you mean by all the dash lights are on?
literally all of them - or just the warning lights?
if it is just the warning lights (mine was showing oil level, coolant low level, battery and rear tail light out) it was solved by replacing the alternator even though it was charging 14.3 volts and after replacing 14.4 volts
just a thought
neil
mate, had this happen to my celsior/ls400 a while back... it turned out to be alternator...
have you had any power steering fluid/oil leak on it? because that also may be causing the problem...
check the voltage charge next time those warning lights show up again... because to me it sounds like either the alternator is detecting faulty charge or it is on its way out
i havnt been able to check it while the lights are on because when you stop they go off, and theres no visible fluid on the alternator from looking underneath? could it just be a voltage regulator?
could be the regulator... see if you can test the voltage from the alternator itself might be a better indication... sort of sounds something to do with the alternator/battery to me...