Weird Electrical Problem With My 95 Sc 300

[SEAN_VANCE]

Hello guys,

I have this weird problem that is hard to explain... Ill try my best...

Sometimes, and it can happen at any time, my car gets the feeling it wants to turn off... but it seems to be an electrical thing because what happens is that the dashboard, radio, lights, and everything that is electrical dims in flashes, like if something was sucking power away from the electrical system, and sometimes it dims so much that the car just turns off. The car starts right back up though. Sometimes it continues doing the problem, sometimes it gets fixed for a few days...then it does it again.

For example, I may be driving then I press the brakes and it dims a little, then I press the brakes and it dims again...etc, etc... then sometimes I press the brake and it just dims so much that it cuts off...but it doesnt only happen with the brake. I can be pressing the cluth, going on reverse and it just dims or turns off...

I have been trying to get this car hooked on the computer but everytime I go to the mechanic, the problem hides away and wont come out for anything, so the computer doesnt read anything wrong.

The other day I was a block away from my mechanic and the problem went away...Ironic...

But yeah, if anyone has ever had this problem and could help please post a reply or email me... Any help would be greatly appreciated! email me at amontano5@excite.com

PS- I checked both battery and alternator and both are good.

[MichaelNeier]

I've been having this exact same problem and any help would be appreciated. I was about to ask about it today and saw this.

Thanks in advance,

Mike

[SKperformance]

i would say an alternator problem

that is intermittent

i used to not be able to idle my car as it wouldn't keepenough chrge to restart

i would also check the wiring

which may need to be replaced if damged for the alternator and starter plus body ground

[shnookie]

Check your main grounds from the Alternator and the battery. Atrn't too many things besides a bad ground that can effect the whole system across the board. Pull the grounds off and have the contact points cleaned.

[Bubbles]

The alternator is probably part of the problem. When I shift gears and sometimes I let the rev drop back to idle, the heater dims a bit. Also, for me the battery terminals were dirty. I took sandpaper (or a wire brush) and just lightly sanded it so the shiny metal is exposed. Don't scratch it too deep or else there won't be enough contact surface between wiring harness to battery terminal. Once I did that my headlights wouldn't dim anymore when I hit the brakes.

[SEAN_VANCE]

Thanks alot guys,

I will check all my grounds and stuff.... I will keep you guys posted....

also...is there any way to check your alternator without having to take it to tha fancy mechanics machine?

Im wondering because if its an intermitent alternator problem, it would be great to just pull over and check if the alternator is working while its doing the problem...it has been impossible to have the car doing the problem while at the mechanics...

Thanks again guys!

[SEAN_VANCE]

Ok...

I checked out my grounds and everything looks great... nothing loose or corroded...

I have a question for MIKE....the guy who's having the same problem as me....

When the problem comes out, have you noticed that your antena doesnt retract sometimes? I mean, you turn the car off and the antena stays up...

Also, do your fog lights work? For some reason my foglights dont work and there is no power going to them... I checked the ends and no current is going through...

I tried to follow the wires for the foglights but it gets too complicated since it goes between the quarterpanel and chassi....

they were working fine before but not anymore.......

If anyone has any ideas please let me know..thanks!

I checked to see if there was a fuse for foglights and I didnt find one....

BTW, I dont have the owners manual so I have ANOTHER question...

Are the only fuses for the SC found under the hood of the car? OR are there any fuses inside the car hiden somewhere.

Thanks! ;)

[MichaelNeier]

Yes, there are fuses under the hood. Both on the driver's side. One is a small one for the trac system and the abs, the other requires !Removed! out two screws. I have not noticed any problems with my fog lights as of late, but have noticed that the warning light for a light out has been coming on and haven't found a light out. I haven't noticed a problem with the antenna, but usually only listen to CD's. I have checked the battery and tried sanding the connectors and terminals and tried driving around and haven't noticed a problem. I will try again later tonight with the lights on and after sitting for a while. Usually the problem eventually would go away after the car has been running for a while.

Thanks,

Mike

[JPI]

Check your connection and wires again. Look over everything really good. When was the last time you do anything to your car? Is your alternator putting out enough ? Take it to autozone or some other place for them to test your alternator. Also tell them to do a load test on your alternator. Let me know how it turn out.

JPI

[SPORTcoupe300]

I agree with JPI about checking the wires again (and again, and again).

I've had this problem (not on a Lexus) but this exact same problem.

I checked the wires and all seemed fine.

Have you guys ever gotten into the car and upon turning the key, just got a click?

Well eventualyy that's what happened to me and I went out and got a new started (stupid me), intalled it and nothing. Still click.

My dad ended up fixing the problem by taking off my positive connection off my battery and cleaning all the crap inside. It was one of those that the connection actually screws into the battery.

I didn't do this because I was told only the negative corrodes.

Anyways, as I said, take off first the negative, then the positive off the battery. Clean them both with a wire brush, wipe em off with a clean towel, and put them back on.

Good luck!

btw...test for working alternator is simple.

1. Start your car

2. Take off negative terminal off battery

a) Car Stays On - Good Alternator

B) Car shuts off - bad alternator

[MichaelNeier]

As I said I cleaned the terminals and connectors today and drove around town tonight with no problems and no dimming headlights. Thank you all for helping. This was driving me crazy.

Thanks,

Mike

[Bubbles]

I don't think you should take out the negative post from the battery while the car is on. It'll strain the alternator so much it's gonna break so you'll end up thinking the alternator is the problem.

[Manolo]

Mine had the same problem, and I checked the rotors and the cap, and they were rusted and corroded. I bought new rotors, and new rotor caps, and my problem went away. I thought It was a wire or something, but after i fixed the rotor problem, everything went away. Myc ar hasnt done that in the past 5 months since it last did it, so u might wanna check that out really quick, u never know.

[MichaelNeier]

The problem returned today. I went to O'Reillys and they said the battery was fine, but it was the alternator. They hooked up a machine to the battery and when i braked the voltage dropped on the battery. I looked at the alternator and the power connection had gotten so hot that it burned through the plastic cover that covered it. I have also noticed my ABS light came on last night and has not turned ooff since. I have no clue what to do. It only seems to be a problem when I brake so I'm thinking that my ABS has a bad ground or something like that and when I brake it causes problems all over or my ABS is just shot. It's probaly my alternator or my ABS. Any opinions?

[SPORTcoupe300]

THe melted plastic on the alternator means that the connection at that point is bad.

Take off the plastic stuff and you should see that the nut holding down that wire is loose.

It heats up because it constantly looses contact and is trying to put 50+ amps through a hair of a wire.

I really don't think this problem is with the ABS.

It is definitely a connection problem.

BTW. Taking the negative off the battery should have absolutely no effect on the car (if the alternator is ok).

While your car is running, the battery charges. It is not used(or shouldn't be) at any point in time while the car is on.

The battery in a car is just there so you can start the car. The alternator takes over from there.

So once again, a valid test of the alternator is to tak eoff the ground while the car is running.

If it turns off, you either have wiring problems or the alternator is bad.

[MichaelNeier]

......

Well,

I went to go work on my car and took off the alternator power contact and cleaned it, after a while i dropped it and many sparks started coming off. I had not disconnected the battery. I disconnected the battery then reconnected everything. Now nothing is working. The car will not start and I cannot even lock the doors. Could this all be because of the alternator or has worse things now happened.

I'm scared,

Mike

[SPORTcoupe300]

Eeeeek. :o

Whenever working with electronics, you need to always disconnect the battery before doing any work.

But now that it's too late to tell you that, I say start (after making sure your battery is disconnected) by checking all your big fuses under the hood.

If that doesn't work, then I'm not sure what happened.

Sparks are bad. :(

[SEAN_VANCE]

Hey Mike,

Hey dude, dont worry....its just a fuse somewhere...all electrical circuits in these cars are protected by fuses, just like homes...you just gotta find it and replace it...

As far as my problem,

Im gonna try that distributor thing. Hadnt thought of that... my alternator seems to be working fine, nothing is corroded or melted so for now Im going to asume the alternator is ok...

Thanks again everyone!

[SKperformance]

i agree

the alt will not get damaged unless it already is

and it doesn't run off the battery except to start

also when checking wires you need to check both ends not just by the terminals

mine corroded on the main body ground under the battery tray

[MichaelNeier]

Yeah, that fuse is toasted. Getting a new one today. It was suggested that it was the voltage regulator which I believe is in the alternator. It's getting more and more likely that I will be getting a new alternator soon.

Thanks for the help,

Mike

[SPORTcoupe300]

the VOltage Regulator can actually be bough separately at a much lower cost than replacing the whole alternator.

If you can find a shop that actually know what they're talking about, you can save some money.

Here's a link:

http://www.partsamerica.com/PartDetails.as...ype=204&PTSet=C

Good luck!

[SEAN_VANCE]

Well....I did the Rotor and cap change and I think that fixed the problem... the rotor was oretty ragged and I think it was the original from factory because it was made by Denso... my car just completed its 100thou mile-iversity, so that definitely needed to go.......

So guys..if your car is acting weird like this, change that damn rotor!

Thanks everyone 4 ur help..I will report any updates.

PS Im going to Orlando all next week so that would be the super test. :D :D :D

[SEAN_VANCE]

Well....sad to say that the rotor was not the problem....my car still doing the same thing........what the hell is going on???

Who knows...I guess I'll have to wait until the car breaks down and leaves me stranded!

:o

[EvaFearless]

Hey everyone,

I have a 1992 Lexus es300.

I am having the same issues practically. All of my dash lights went out when I started my car, and the AC doesn't work, nor the cigarette lighter. They do not flash or turn back on.

The car starts great! It can go on the highway and drive like a dream. But when idling at a red light, stop sign, or pulling into the drive way, I hear a small click (like a light bulb noise) and the car completely shuts off, engine and all.

When all of this happened, here is what we did:

I did have a loose battery cable, so we changed that and both are new and secure now.

I replaced the air filter, which had been rough and moderately dirty.

We replaced the fuse related to the dashboard (not sure which one, but you experts probably already know), and it started working.... until about 10 mins later the fuse blew. And then we tried again and it blew again. So I am guessing I have a short.

Can anyone point me in the right direction? I would appreciate it like nothing else.

Also, this doesn't look right... Don't know what it is or why it's like this. #Helpasistah

THANKS!