battery warning light and (!) warning light

[M.T.Pilot]

Hi,

I've got a toyota Starlet (1989) which allover sudden showed two warning lights from start-up on:

*(!)-warning light indicating a problem with the brakes, and:

*Battery/discharge warning light indicating a problem with (charging) the battery

I had driven the car without any warning lights or problems just a couple of hours earlier. Then when starting the car it gave those two warning lights and they stayed on throughout the drive home.

Checked the brake-flued level, was okay. Cleaned the battery connectors.
Then took out the big (three point) connector-plug at the dynamo, turned the ignition key on "ON" and both warning lights were NOT on anymore.

Any idea what conclusion can be drawn from this?

regards,

M.T.Pilot

[ShawnM]

Sounds like your alternator (dynamo) is bad. I would start with the charging system problem first. Once you fix that both lights will probably turn off.

[M.T.Pilot]

cheers Shawn!

I think you are right.

I did a little test that is supposed to tell if the problem lies with the battery or with the alternator: I started the car (without a problem) and unplugged the negative side of the battery. Someone told me that when you do that and the car dies, then you know it is the alternator-side that is causing the problem, as normally, the alternator should keep the car running when you do that..

The battery itself gives out a 12.63 Voltage when the car is not running, and a 12.23 Voltage when it is running (without lights on and such..).

Now, from what I read in other postings on this forum, it could either be the ALTERNATOR, the WIRING, or the VOLTAGE REGULATOR that is causing the problem, if it is not the battery.


I'm not sure how to go about finding out what is the exact cause. I took out the alternator, opened it up (to a certain degree), but did not see anything strange. Well..things are a bit rusty, to be honest..

Also, july 2007 I had already replaced the carbon contacts thingies in the dynamo (don't know the English word for it..), so that is not the problem either (they still looked good anyway..not to worn down and they were not stuck either).

However, I have no idea what a voltage regulator looks like and where I can find it in the starlet..

I want to check the wiring, but I'm not sure how to go about that either. I do have a voltage checker.


What I find strange is that it happened alloversudden.. I had been driving the car a couple of hours before, without any problems.. I then start it again, and the problem is there.. I though alternator dying signs are petering out, instead of a sudden die off..

Anyway, any or all help is appreciated!


regards,

M.T.Pilot

[M.T.Pilot]

Okay, I was able to borrow another alternator, and found out that the alternator is causing the problems.. Anything one can do to repair an alternator? Or should I simply buy a new one? (I believe the voltage regulator is internal.. is there a way to check if the internal voltage regulator is the problem?)

regards,

M.T.Pilot

[toyomoho]

The alternator should put out around 14- 15v when charging the battery.

Normally to test the regulator, terminal F on the alternator would be grounded and the voltage at the battery read (engine on all accessories off). If the reading is more then 13.9-15.1 (everything cold) the voltage regulator is bad, if less then this voltage the alternator has a problem.

Given what you state sounds like the alternator is not making power, Perhaps one of more diodes are bad.

In the future it is better to use a voltmeter to read alternator output voltage at the battery. Disconnecting the battery when the engine is running can damage the alternator regulator, the test is safe for older cars with generators, but not alternators.

[Donald]

Unless you are very electrically inclined I would suggest you take the alternator to an alternator repair shop, or get a new one.

The regulator is internal.

I have been told that the most commom cause of alternators dying are,
(1) loose/corroded battery connectors.
(2) Giving someone else a jump start (boost) with your engine running.
Giving a boost with your engine running can overload your alternator diodes and it might be a long time before it dies. Because of the time span between the two events, many people don't draw a connection.

The solution to #1 is obvious.

For #2, when giving a jump start:
Turn your engine off, connect the cables, try starting the other car.
If your battery doesn't have enough power to start the other car:
Switch off the other car, start your car and let it run for abour 5 - 10 minutes to charge up the other battery.
Turn off your car and try starting the other car again.

[M.T.Pilot]

cheers folks, much appreciated information!

I bought a new voltage regulator, which didn't do the trick, even though the old one was part of the problem (I had it tested). Then I bought another part, which is also a diode, I believe.. I'm not sure how to describe it .. It is basically the part next to the internal voltage regulator (and not the carbon thingies-part).

However, I have not had a change to put the alternator in and test it. Will do so tomorrow. I hope that will do the trick, because if not, I will have to buy a whole new alternator after all, and will loose the money I already spend on the parts...

The reason for the death of the regulator is probably both the points you (Donald) mentioned. I did have a loose connected at the + pole for some time AND I had to jump start my own car with a generator and battery charger..

Thanks again guys, I'll update when I've been able to try out the alternator with the two new parts.

regards,


M.T.Pilot

[M.T.Pilot]

UPDATE:

I have replaced all parts under the "hood" of the alternator that can be replaced, but to no avail...

I guess it must be the coiling part of the alternator...

I replaced the alternator with a second hand one. The car is working fine now..

Still curious as to what in the coiling-part of the alternator could have caused the problem...

Thanks for all your help and advice! Appreciated..

M.T.Pilot