Alternator? Starter?

[JDanW]

I have found some great information on this forum and thank all involved, but now I am at a point where I am not sure which way to go.

BACKGROUND: I replace the alternator with an Advanced Auto reman. This was diagnosed by checking battery (it died and was replaced) with a multimeter. Read fine while sitting, but was not right once started, so I replaced the alternator.

CURRENT PROBLEM: The car won't start. Lately it has seemed like the battery was weak, as in starter seemed weak. I checked again with multimeter and it actually reads a little high, like between 12.5-13.5v. It still reads this while sitting, but the car won't start. When cranking, the multimeter drops much, I remember seeing 2.6v. And since replacing the alternator, the lights "pulse" and dim, getting progressively worse.

QUESTIONS:
1) Would a weak/going-out starter act like a weak/dead battery?
2) (I'm going to ask Advanced Auto this as well) Is there a way to test the alternator without removing it?
3) Are the regulators integrated in the alternator? Would those be the likely source of lights acting up? Or the alternator itself?

Thanks for reading this and any help. I am not so sure I want advise like "don't buy Advance Auto parts, they're junk" or similar, unless I can get better quality for nearly the same money. I know I am fixing a problem that might be caused by their alternator, but I have lots of time, but not a lots of money. My choice, just so you know, but now that I say that, maybe someone can convince me to treat the Q better. Also, I hope I don't want to sound like an idiot, but honestly I think I know what's going on, but want some reassurance and/or better advise form someone who has experience this kind of crap...

[Lokim]

Will it start if you jump it? If so, take it down to the parts store and ask them to do a starting/charging system check. Almost every store has a snazzy little doohickey that'll prompt you through all three tests (Battery, alternator,starter) and they are usually pretty accurate. Report back with results.

[Q451990]

If you're seeing your voltage drop down to 2.6 volts when the starter is engaged, you definitely have a charging or battery issue. It should drop some... maybe to 11VDC while the starter is turning, but that's about it.

If you can get the car started again, check to see what kind of voltage you're getting at idle at the battery. You should see something slightly above 14VDC.

To answer your other question, - yes, the voltage regulation is built in to the alternator...

Good luck!

Heath

[LoxMurda]

Raise car. or turn wheels left all the way. Right between lower manifold and trainy is starter on passenger side. Hit a couple times with something stiff. yeeeahh.... she likes it stiff. Start car. Car start? Replace starter. Car no start ...not starter...look elsewhere.

[Skibane]

1) Would a weak/going-out starter act like a weak/dead battery?

Yes. If the starter is binding up or the brushes are worn out, no amount of battery power will spin it at full speed.

2) (I'm going to ask Advanced Auto this as well) Is there a way to test the alternator without removing it?

They should be able to use a load tester on it - Basically, they apply a heavy electrical load to the battery while the engine is running, and measure the voltage being produced by the alternator. If the alternator can't supply enough current to replace what is being drawn by the load tester, the voltage will measure lower than it should - which means that the alternator needs repair or replacement (or you've got an alternator belt slipping).

You can also do a more basic "load test" yourself - Turn on your high beam headlamps with the engine running at idle, and measure the voltage at the battery posts. If it's down in the 12's (assuming your battery is fully charged), your alternator isn't cutting it. Ideally, the voltage should be in the high 13's or low-to-mid 14's.

3) Are the regulators integrated in the alternator? Would those be the likely source of lights acting up? Or the alternator itself?

Yep, the regulator is built into the alternator housing. If either it or the alternator fails, you could see problems like you're experiencing.

[JDanW]

WOW, was waiting to go to store tomorrow, but now have a few things to try...thanks for the responses, will hit back with any news...JDanW

[JDanW]

Does anyone have a comment on the battery while off reading 13.89v? Am I doing something wrong to get this reading? I have not gone to the parts store yet, because they said they have to turn it off to run some of the tests and I really don't want to be stranded there if it won't start again...

Also would heat make a difference? As in it starts better later in the day, or after it has been driven somewhere?

[Skibane]

Does anyone have a comment on the battery while off reading 13.89v?

It's probably not anything to be concerned about. If the engine has been running recently (and the alternator is working), the battery voltage may be a lot higher than its normal "resting" voltage of around 12.7 volts. Basically, the battery retains the alternator's higher charging voltage for a while after the engine's been shut off, until it's had a chance to bleed off. If you let the car set overnight and then measured the battery voltage the next day (without running the engine beforehand), you'd probably measure something closer to 12.7 volts (assuming your alternator is working normally and your battery is fully charged).

Also would heat make a difference?

Yep. The starter can spin a warm engine a lot easier than a cold one, because the engine oil is a lot thinner after the engine warms up. Also, the battery is capable of supplying more cranking current in warm temperatures - and a hot engine compartment will warm it up nicely.

[JDanW]

Skibane, thanks for the thorough responses. Unfortunately, the car has been sitting without starting for a few days and the reading is still 13.89v. I guess I'll roll the car out in the sun and see if I can get it a little warmer. Thanks again.

Any differing views? (I doubt it, as this sounds pretty solid)

[Skibane]

If the battery voltage is still reading 13.89 volts after sitting for several days, I would suspect a problem with the meter.

Any chance of buying or borrowing another meter to get a "second opinion"?

[Q451990]

Also make sure the battery in the meter is good... they do all kinds of weird things when they get low voltage.

Heath

[JDanW]

Well, this was a good exercise in thinking...BUT, the battery was defective. New about 6-8 months ago. AdvanceAuto says laternator giving 14v, said started was good, and 700CCA battery as reading 112CCA. Battery read 13.89v, just as my MM said, so no need for new one of those. Thanks to all for the responses and help...I have another thread about the antenna, if anyone wants to pipe in about that and I will be asking about some more upcoming work to be done. Thanks again...