Alternator round 2!? + new rotors!

[Crimson Fury Z]

well, today i slapped new rotors on the front and was happy that the infamous pulsation was gone. in town, i hit the brakes and the car dies. last time this happened i cleaned the + terminal and all was well. it took a couple of minutes to get the car to start(the guages and lights weren't coming on during that time), after tinkering w/the + terminal. the battery guage reads 1/4(whatever volts that equals). so far the battery is taking the charge from the charger. i haven't noticed dimming lights of any kind, just a periodic power loss/cut out when i'd hit the brake pedal, then electrics would come back on after letting off the pedal. what do you guys think?

 

[chadz34]

It could very well be an alternator starting to go, when the check engine light comes on, you probably won't make it to the shop, so I'd take it there now.

[Crimson Fury Z]

haven't had the ses come on......yet! nor did it when the 1st alt went.

[chadz34]

haven't had the ses come on......yet! nor did it when the 1st alt went.

That's werid the light should have came on, it did on my 92' Lumina Z34 when it went out. It died 3 days after the SES light came on. I'd go to a shop and have them test your alternator.

[Crimson Fury Z]

definately getting that checked.

[pitzel]

These alternators (CS-130) are pretty easy to diagnose and repair (if necessary). There are only 4 failure modes, and 2 of them aren't that difficult to fix:

 

1) Flickering of digital displays when the car is running -- diode failure, replace diode assembly.

2) Significantly changing voltage when brake pedal is depressed or another load applied -- voltage regulator failure, replace voltage regulator.

3) Brushes, these things rarely fail before the voltage regulator/diodes do. But not hard to replace either.

4) Bearings -- shows up as physical noise from the alternator under the hood.

 

You clearly have a case of #2. So either pull the alternator apart and replace the voltage regulator (some soldering might be required), or get a new one.

 

Do it quickly -- if you leave this for a few weeks, the result will be that you probably will need to buy a new battery in the process because of the deep discharge cycles you are exposing the battery to.

[slick]

I have a fully rebuilt alternator from my shop back home. I gave him one of my bad ones, and he rebuilt everything in it with much better parts, still puts out stock voltage output. If you want it, you can have it for $75 plus shipping.

[Crimson Fury Z]

dropped off tuesday afternoon, went in wednesday & finished wednesday, picked up today! i asked about using my own alt. but he said there'd be no warranty if something went wrong w/it(= no free repair)

[slick]

You didn't change it yourself????

[Crimson Fury Z]

....nope............

[1990lumina]

FYI my SES light didn't come on until AFTER the engine died when my alternator died. But my cluster doesn't have a voltimeter so maybe that is why....I think in '91 GM replaced the oil pressure guage with the voltimeter one...

[slick]

If the vehicle senses low voltage, usually the ABS light(if the vehicle is equipped) will come on.

[Crimson Fury Z]

and i thought my abs was on its way......................