Alternator Problem in MR2

[mister_two]

Hi there,

my battery light keeps comin on, was thinkin maybe the alternator was stuff but the problem started when my spare wheel came in contact with the positive terminal of the battery, could it just be the wires?

any tips before i pull the alternator out ( which is a damn hard job )

cheers

[Twolitre]

Spare wheel incident was probably coincidental, measure the voltage of the battery while the engine is running and if it's between the 13.5 - 14.5 volt range then the chances are the alternators probably fine, if not replace it before you get stranded somewhere.
How old is the battery? Maybe it's not holding a charge anymore?

[mister_two]

dont really know how old is the battery, never replaced it though ever since i bought it, but yeah I'll try the volt meter see if its charging
I prefer the battery dying than the alternator, its so damn hard to removed them..cheers anyway bro

[mister_two]

allright, not reallyan expert with the volt tester anyway

tested the battery at AC/ Volt and its about 19.5

but tested it on DC/Volt its about 11.5

whats the meaning of this? is my alternator gone

please help

[Dragger_Dan]

You should have about 13.5 to 14.5 volt when the car is running, and about 12.8 volt when the car is not. Is your DC reading of 11.5 when the car is running or not? Don't forget, most auto electricians or battery shops can test your battery for free. Check the level of the battery, if the water is not 3mm or so above the plates, then add distilled (boiled and cooled will do if you can't get distilled) up to that level. Also don't despair, charge circuts have relays and fuses in them, so check all those before comitting yourself to a new alternator.

[mister_two]

Yeah I am reading some where around 11.5 DC
is that good or bad

well, maybe i'll go get my baterry check out first..then go from there...

i cudn't find the fuses aswell anyone know about the MR2 setup of fuses and relays? lookin for the one called IC regulator

[sopachrga]

BAD!!

Your alternator is not charging. you should have about 14.5 volts.

The battery itself is 12 volts (a bit lower depending on the drain)

Time to get an alternator rebuild!!!!

[sopachrga]

There is not much point in getting the battery checked, the alternator should be putting out a lot more voltage than that.

You could look at the wiring and see if there is anything broken but it does not sound too good.

the Brushes in the altrnator wear and that will cause that problem.

If there was a problem with the battery you would still have the voltage there, but the car would still go flat. The battery can get to the stage where it can not hold the charge.

PS, You did have the car running when you tested this??

[mister_two]

yep , the car was running when i tested it...DC/volt aroun 11.5

so maybe its really time to pull out the alternator

[sopachrga]

Sorry to say it, but it sounds that way

[matt dunn]

Hi there,

my battery light keeps comin on, was thinkin maybe the alternator was stuff but the problem started when my spare wheel came in contact with the positive terminal of the battery, could it just be the wires?

any tips before i pull the alternator out ( which is a damn hard job )

cheers

The spare wheel came in contact with the battery?

Was the car running at the time?
If so it will/may have blown the main fuse for the power to the alt.
This will cause the same symptoms.

Should be an 80A fuse, and will be bolt in type.

Matt

[sopachrga]

Hmmm? I did not read that far up....

That could have a lot to do with it

[Dragger_Dan]

I'll scan haynes for you in a few minutes.

**hang on, is this mark 1 or mark 2 MR2?

[mister_two]

hiya this is the SW20 one mark II, I think

anyways thanks for all your help guys,

just pulled out the damn alternator today, man its so frickin hard!!

got it tested on an alternator shop and bingo it was STUFFED!

cheers again for the help

[RomanV]

When topping up the oil, try not to spill any!

If you look where the alternator is positioned, any oil that gets spilt drips straight down onto the alternator.

Im sure its a cause of many alternator deaths in SW20s.