Someone Pleaseeeee Help With A Fuse Question

[i_need_help]

OK.....yesterday, my 1990 Lexus LS400 started acting up. First the panel lights flickered, and the radio went out, then the headlights went VERY dim, then the car just shut off in the middle of driving. The lights STILL come on (barely), the automatic locks still work....but the car will not start at all, so I KNOW its not the battery. For a little, the car would TRY to turn over, but now its not trying to turn over at all. I have had some people tell me, its the alternator, and others tell me, it could be just a simple Engine fuse or Starter fuse blown (which would be the easy way out). My question is, WHERE THE HELL IS THIS STARTER FUSE AT!?!? I looked all night and could not find it, the manuel says it is RIGHT next to the other 15 fuses in the drivers side under the steering wheel and all that...but its not there. Does anyone know where to find the starter fuse?!?!? THANK YOU SO MUCH!!!!!!! :cries:

[larryp]

Probably an alternator problem, but right now the issue is your battery doesn't have enough charge to turn the engine. Have you tried jumping it? You may want to take the battery out and have it charged and tested. If you can get it running and there's an auto parts store close by, they can test both the battery and the alternator while still in the car. If you can't get it running, address the battery first and you may have to take the alternator out to have it tested.

More than likely the engine died because the alternator wasn't charging the battery and you were running off battery alone until it became too discharged to continue to run the car.

Based upon your description, i doubt it's a fuse.

[SKperformance]

Alternator is suspect otherwise a ground wire to it or the battery.

[1990LS400]

It sounds like the battery to me. Is it over 3 years old? I had very similar symtoms several times over the nearly 14 years I had a 90 LS (and once on my 00 LS) and it always turned out to be the battery. Do you have a battery (specific gravity) tester? Consider buying a cheap charger and see if the battery will hold a charge.

[sha4000]

this sounds like your alternator just forthe simple fact that your car was running when it went dead. the battery supplies the power to turn the starter which starts the car then the alternator takes over to supply most of the power to the accessories while the car is running and charging the battery back up for the next time you start your car.this isa simple problem to figure out, get aboost and take your car to autozone where they will check the battery & alternator for free, then get back to us

[1990LS400]

Just going over a small bump is enough to momentarilly jar a connection between battery cells loose on an old battery and and make the car die. The engine on my 00 LS died a couple of years ago when I made a low speed turn into a parking lot and hit a small pot hole. The battery was just under four years old. I barely got the car running and drove directly to get a new battery. It has not died since.

But yes, it could be the alternator - especially if a defective power steering pump has leaked fluid on it - a very common problem on the gen 1 LS. It definitely pays to make a fluid shield for the alternator out of a plastic bottle. Search this forum for information on how to do this. I should have done this on my 90 LS. I went though several alternators and several power steering pumps over the 14 years. And it was on its 5th battery - they failed like clockwork every three years - even with closely monitoring the fluid and using only distilled water.

[Leadfoot]

I don't think its fuses, but to answer your question the starter circuit is fed by a relay that is found in the engine bay junction box (next to the battery). This relay is fed by a fusible link (use a torch to see into the top of the link to see if it is burned out). The fusible links are next to the junction box and are BOLTED IN so if one of these is blown don't try and pull it out. You have to disassemble the fuse link holder and unclip the side covers to get to the retaining bolts. Might seem like a hassle but they didn't want them to ever come loose own their own!!

I had the same sort of thing happen to me and it turned out to be a failed alternator. To check this take the covers off the battery terminals when the engine is running and check for

13.9–15.1 VOLTS WITH ENGINE RUNNING AT 2000 RPM AND 25°C (77°F)

13.5–14.3 VOLTS WITH ENGINE RUNNING AT 5000 RPM AND 115°C (239°F)

If you don't have the above then you are running off the residual charge in your battery, and you won't get far. Alternators tend to go because they are situated under the power steering pump, so check that the power steering is not the root cause of the failure.

Good luck.

Leadfoot.

[lenore]

I agree a bump in the road could cause the cells to short in the battery if there is crud on the bottom near the plates. This could wipe the alternator diode assembly. Probably a bad alternator and battery.