88 Corolla Brake/Battery Warning Light On???

4822 Views 36 Replies 10 Participants Last post by homeguard, Jul 14, 2004

Big Chaze

Discussion Starter · Jun 28, 2004 (Edited)

My wife has an 88 Toyota Corolla (4af, I think) and the brake and battey light came on at the same time. Her car was on and all of a sudden, all the accessories wanted to turn off.
We turned the car off, and it would not start again. I assumed the problem was the alt. since it has never been changed, so I replaced it with a new one. The car has started up fine ever since,.. but the brake and batt. light are still on. The brake res. is full just above the max line.
Should I change the battery??? When I used a voltmeter,.. it read 13v's while off,.. and 14v's while on. I turned the headlights on and the volts dipped and went back up fine.
Is the battery suppose to measure 13 volts while off?? I thought it was suppose to measure 12v's???
Could this be the problem???

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homeguard

· #2 · Jun 28, 2004

whats it do when you try to start it?
edit: try jumping it first also.

Big Chaze

Discussion Starter · #3 · Jun 28, 2004

homeguard said:
whats it do when you try to start it?
edit: try jumping it first also.

I replaced the alt. and it started fine. It has started fine for the past week and a half. The alt is charging the battery fine also.
The car cranks and starts right up,... but the brake and battery warning lights are still on.
Now her radio wont' start,.. I'm thinking there's a short somewhere but I cant find it. Why would both warning lights come on at the same time???
Any suggestions????

Tercel GTS

· #4 · Jun 29, 2004

The alternator may still be bad, might be working, but not in a proper manner. Also check the regulator.

homeguard

· #5 · Jun 29, 2004

you check all the fuses?

SR5 Rolla

· #6 · Jun 29, 2004

My brake light wouldn't go off. Check your brake fluid level first. My front pads were fine, but I needed new drums in the rear so check it out.

homeguard

· #7 · Jun 29, 2004

i think the only sensor with the break light is on the hand break im not sure though, i am gussing this is a sedan?

Big Chaze

Discussion Starter · #8 · Jul 1, 2004

homeguard said:
you check all the fuses?

Yes.
But one fuse is bad,...it's the one under the hood that says "CDS".
it's one of those big peach colored fuses.
I replaced it,.. but the lightdidn't go off.

Big Chaze

Discussion Starter · #9 · Jul 1, 2004

SR5 Rolla said:
My brake light wouldn't go off. Check your brake fluid level first. My front pads were fine, but I needed new drums in the rear so check it out.

Brake fluid is topped off.
I have to check the brakes themselves.
The reason I didn't,.. is cause the charging light is on also.

Big Chaze

Discussion Starter · #10 · Jul 1, 2004

homeguard said:
i think the only sensor with the break light is on the hand break im not sure though, i am gussing this is a sedan?

How can I tell if is't the parking brake???
Both lights get brighter when I apply the p brake.
Could this mean something??

REN69

· #11 · Jul 4, 2004

If the break light AND the battery light come on at the same time, chances are its your alternator, I learned that recently from experience. The alternator charges about half the time and the other half it will give low charge, this is why the brake/battery light comes on, it indicates that your alternator is producing a low charge (under 12V) and eventually it will stop charging.

If the brake light alone comes on, that means that your brake fluid is low, not that your brakes are broken or anything like that.. the only sensor is located on the brake fluid bottle and that's it, there's no sensor for worn out pads/shoes(well except for the squealing spring on brake pads) or broken parking brake cables.. you get my drift?

However there is a sensor on the brake lever that turns on when you put your parking brake on, this explains why your brake light gets brighter.

Big Chaze

Discussion Starter · #12 · Jul 5, 2004

REN69 said:
If the break light AND the battery light come on at the same time, chances are its your alternator, I learned that recently from experience. The alternator charges about half the time and the other half it will give low charge, this is why the brake/battery light comes on, it indicates that your alternator is producing a low charge (under 12V) and eventually it will stop charging.

If the brake light alone comes on, that means that your brake fluid is low, not that your brakes are broken or anything like that.. the only sensor is located on the brake fluid bottle and that's it, there's no sensor for worn out pads/shoes(well except for the squealing spring on brake pads) or broken parking brake cables.. you get my drift?
However there is a sensor on the brake lever that turns on when you put your parking brake on, this explains why your brake light gets brighter.

Well,..thats why I changed the alt. first.
But both warning lights are still on.
The new alt is charging fine. I've checked the battery once a day for the past two weeks and it measures the same volts (13v's).
I checked the battery and it's in good condition.
What else could it be??

REN69

· #13 · Jul 5, 2004

hmmm.. bad ground maybe. maybe even a bad fuse.

and yes.. my alternator did charge fine.. but only half the time.

Big Chaze

Discussion Starter · #14 · Jul 5, 2004

REN69 said:
hmmm.. bad ground maybe. maybe even a bad fuse.

and yes.. my alternator did charge fine.. but only half the time.

I checked all the fuse before changing the alt.
How can I tell if I have a bad ground???

CanadaGTS

· #15 · Jul 5, 2004

I had that problem with my 4af also if you changed the battery and the alternator and the light didn't go away, also check the battery terminals if that still doesn't fix it then it this. its the main power wire on the postive side this same wire controls the choke on the car i think its a yellow wire, that wire is corrode or starting to break down over all the years and weather conditions like mine did so what you need to do is jump the wire from the alternator to the main power wire on the battery that way there two way for the power to get through the system. it took me 6 months to figure out the problem. it costed me 2 battery and alternator, over time is will overcharge the battery and burn the inside of the alternator. this should fix your problem like me know the outcome.

Big Chaze

Discussion Starter · #16 · Jul 5, 2004

CanadaGTS said:
I had that problem with my 4af also if you changed the battery and the alternator and the light didn't go away, also check the battery terminals if that still doesn't fix it then it this. its the main power wire on the postive side this same wire controls the choke on the car i think its a yellow wire, that wire is corrode or starting to break down over all the years and weather conditions like mine did so what you need to do is jump the wire from the alternator to the main power wire on the battery that way there two way for the power to get through the system. it took me 6 months to figure out the problem. it costed me 2 battery and alternator, over time is will overcharge the battery and burn the inside of the alternator. this should fix your problem like me know the outcome.

Not sure which wire you're talking about,.. but I cleaned out my terminals already so i doubt thats the problem.
I'll try the wire solution, but I dont know what wire.

Peter

· #17 · Jul 5, 2004

check ur bat then ur alt then come back and tell me

CanadaGTS

· #18 · Jul 6, 2004

ok tommorrow i'll get the exact wire colour and hopefully i can find the wire diagram for the 4af engine. It not your alt or battery on the 4af just the battery light wil come on. for 4ag both those light come on. now i'm like 90% sure that it the same problem i had with my 4af. i'll post if by 10pm wednesday night

CanadaGTS

· #19 · Jul 6, 2004

ok i found it, unplug your alternator there should be three wires from plug a yellow , white and a black and yellow. teh problem is the yellow one cuz it runs to teh choke then to the battery, do you notice that sometimes the car's rpm is low, this wire cuz that problem also. anyways get a new wire a little thicker than the yellow one join that new wire to the yellow but don't cut off the old one you still need it so now the yellow wire splits into two run that new one all the way under the rad support till you get to the postive side of the battery which should have the yellow color and do the same to that wire. so now the power has to ways to get around. but cuting the old wire it messup the choke from the wire diagram the wire passes on both side of it. it a big job to try and renew this wire at that point might as well do and engine swap. anyways that should fix the problem. let me know the out come. oh also when you do all that disconnect the negative also and put back like it was a new battery. why i'm not sure when i did just the postive the light stayed on. when i did both teh light never came back, or it just could be my car.

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Big Chaze

Discussion Starter · #20 · Jul 6, 2004

CanadaGTS said:
ok i found it, unplug your alternator there should be three wires from plug a yellow , white and a black and yellow. teh problem is the yellow one cuz it runs to teh choke then to the battery, do you notice that sometimes the car's rpm is low, this wire cuz that problem also. anyways get a new wire a little thicker than the yellow one join that new wire to the yellow but don't cut off the old one you still need it so now the yellow wire splits into two run that new one all the way under the rad support till you get to the postive side of the battery which should have the yellow color and do the same to that wire. so now the power has to ways to get around. but cuting the old wire it messup the choke from the wire diagram the wire passes on both side of it. it a big job to try and renew this wire at that point might as well do and engine swap. anyways that should fix the problem. let me know the out come. oh also when you do all that disconnect the negative also and put back like it was a new battery. why i'm not sure when i did just the postive the light stayed on. when i did both teh light never came back, or it just could be my car.

Thanks for your help. I'm gonna try that this week.
I'll post back and see if it helped.

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