TeresaS

I am posting for my son, he has a 91 LS400 and last night when he parked all his lights came on inside the car (but engine was not dying) and he smelled burning rubber. Today all his lights inside are on. Where do we begin troubleshooting? Recently he did replace his air filter.......

Yamae

Could he identify from where the burning smell come from?
The symptom looks like the contact problem of the ignition switch to me. If the smell was coming from the steering column, it would be caused by the burnt contact of it.

Lavrishevo

iTrader: (1)

Also check the wiring harness at the trunk hinge. I think that was a common problem too.

TeresaS

now I am thinking it might have been the alternator belt....... because, I had noticed his passenger door was slightly open and his battery was drained. We charged his battery today and moved his car but left it running to charge the battery more. Well guess what? All the lights were on and the car died and when I tried to start it, I just got clicking......

Legender

With the door open, sounds like you drained the battery... you really won't charge the battery much by leaving the car running... You need to test the battery for voltage and make sure it's still good. If you're only getting clicking, then you don't have enough battery. If it will jump start then you need to get the battery fully charged and tested to see if it will still hold a charge. Then determine if it died of old age/end of life... or if there is an alternator problem. The power steering pump can leak and ruin the alternator so need to check to see if that has happened. Once you've got good power then we can work on the other problems...

TeresaS

Okay Thank you! He was coming home and driving when all the lights came on and he says he smelled burning rubber from the engine compartment but the car was still running with no hesitation. The door though had been slightly ajar for a couple days..... We let the battery sit on the charger overnight and will check it soon

Legender

Ok... that's a different story... he could have an idler or a pulley freezing up...that could cause the burning rubber smell and have an impact on the alternator...or the alternator could have frozen bearings... I'd look at the belt closely to see if there are burn marks.... check the belt when you try to crank it and see if spins. It needs to spin freely with no obstructions. Could possibly have something frozen up on the main belt that could be causing problems. Could be the alternator has frozen up... should be easy to verify though.

LScowboyLS

charge battery with a charger (make sure battery is disconnect at both posts from car!)

then wait a few hours to eliminate any surface charge

then measure battery voltage with battery reconnected but car off
then crank car and let it idle and again measure voltage across the battery with car running at idle
post both voltages measured here

the voltage with car off should be 12.5 V or higher, the voltage at idle should be 13.6 volts or higher

if the first one is low, you likely need a battery, if the first one (car off) is good and the second one is low (when running at idle), then you may have a belt or fuse or fuselink or alternator issue

you can watch the car idling with a flashlight or headlight and see if the belt is actually turning the alternator pulley, especially easy to see at night with a light

does this car leak PS fluid on to the pavement ? (leaves spots?)

IMPORTANT: don't forget to check the integrity of the wiring inside the driver's side trunk hinge (in the curve of it) for a broken wire(s) as previously mentioned, this is a very common issue on pre-95 LS400

TeresaS

The battery was indeed bad and not holding a charge. We replaced the battery today. The lights however, still come on. I am going to have to refer to the manual on where the alternator is and the belt. There are no leaks whatsoever on the car of any fluids, including ps fluid. We have not checked fuses or fuselinks yet.....

LScowboyLS

the alternator is below the power steering pump & reservoir, a little hard to see but it is down there, that is why I said to observe at night with a flashlight

the alternator is easy to see from below the car with it up on ramps, once the plastic splash shield is off, but be careful with a car running that you are under, we don't need any kids or moms with a car on top of them!

there is nothing hard to find about the belt, can't miss it, there's only one!

TeresaS

We checked the fuses and we also got the car up on ramps (did not see a splash guard, but did not have any problem finding the alternator either. Started the car and the alternator and everything else was turning fine..... All lights on dash board still on though. Thank you for all the help on this

LScowboyLS

I would locate a splash guard (that may not be the precise name, it is the big plastic cover under the engine) at a junkyard and install it, this protects the belt area and other critical areas from road debris damage as well as improving fuel economy, I bet the junkyard will let you have it for $10, they don't get that much demand for them.

put a voltmeter across the battery terminals with engine running at idle, the voltage should be 13.6V or more, this will verify the alternator is charging correctly

do NOT run the car with the battery disconnected

do NOT charge the battery with the car connected to it (disconnect both terminals when charging battery)

do NOT let a distracted son hook up a charger or jumper cables backwards, polarity (+/-) wise, LS400 does NOT like this, you will burn several parts up

let us know the results, also have your son perform the code check located here and report any codes back here

TeresaS

Also, does anyone have pictures on how to check the fuseable links? I do have a mult-meter and am fairly familiar with how to use it for house wiring.... but have not used it on a car before.

python

iTrader: (4)

battery was ruined because ur alternator is shot...ur lights are on the dash due to ur alternator going out..the burnt rubber smell is exactly what lengender described...

LScowboyLS

before worrying about fuse links, first measure the voltage across the battery, if it is 13.5V or more at idle then your alternator is still working well - did your son hear any screeching or loud noise to go along with the rubber burning smell? - an alternator or idler bearing freeze up is not typically a quiet event, quite the contrary!