I think I need a new alternator. The other day at the end of a two hour drive the "dummy lights" came on & off every few minutes CEL,ABS and few others. I remember when the belt broke the same lights came on and stayed on. When I put the ac & lights on the voltage drops approx 1volt at the cigarette lighter.

I have two questions:

1) Does the above symptoms indicate an alternator?

2) If so where is a good source for an alternator? new/rebuilt?

 

Hi Tom,

Sounds like an alternator. Check your belt tension and make sure it's not slipping. But to be sure, put a voltmeter across the battery terminals with the car running. You should have around 13.5-14.5(max!) volts w/o accessories, and 13+ volts with all accessories on (assuming you have a standard alternator pulley and not the RS one). Any less volatage and you need an alternator.

Source: local parts places like Napa or Autozone. I got one through my local indep mech (who is also a good friend of mine). If you have a good relationship with your wrench, ask him to get you one as it'll most likely be cheaper.

Edward

 

Check your battery first. This is a good way to tell they are about dead. It could be because of a bad alternator, or just a bad battery.

 

Edward, I do have the RS pulley, I left the voltage #'s at home i'll have to ck them later. How lower do u think the voltage would be with the RS pulley?

Bob, I have the Optima red top that is 1 year old & I keep it trickled charged so I don't think it is the battery. How do I check it?

 

Tom,

Haven't a clue as to how much the RS pully alters voltage output ...except that it does, and it's worst at idle. Have someone rev the car to a "cruising rpm" of say 3K and check the voltages. Anything above 13+ volts with all accessories turned on is adequately charging the battery.

Edward

 

I will ck it tonite
thanks

 

1) Go here and buy a plug-in voltmeter (replaces your cigarette lighter)
http://www.cetsolar.com/voltmeter.htm

2) With engine off, plug it in. Shoould read no less than about 11.5V if battery is charged.

3) Start the engine and go for a drive. While driving, voltmeter should read minimum of about 13V; if it's less than that, alternator is bad. If it's more than about 14.5V, voltage regulator is bad.

4) At end of drive, shut the engine off. With no loads, voltmeter should read about 12.5V if battery is good and got charged.

 

When you do the (mandatory ) voltage checks at the battery, stick the probes on the cable ends ... and then into the lead terminal posts: if there is any deviation, remove and clean the surfaces. Sometimes, even a loose connection is found this way ....

 

I took measurements tonight.

Engine off at battery=12.3v (no difference before or after terminal
At idle no load 14v
At idle with load 11.92v

Do I need to order an alternator?

 

Hi Tom,

Your voltages look ok to me. I assume that 11.92v was at idle --the RS pully is just turning too slowly to keep up. Did you try it revved to 2500-3000rpm with all accessories on? The reason I ask is that you are obviously discharging the battery at 11.92v., but who sits around at idle long enough to discharge a battery (do you do a lot of stop-and-go commuting; maybe that's it?).

If you find that you measure at or above 13v at cruising rpm, then your alternator is ok. I'm starting to think your battery is going south on you and is either not maintaining a charge, or not accepting a full charge --pretty common either way. I know you said you have an optima at <1year old and you keep it trickle charged, but in my yeeears of replacing batteries over numerous cars/motorcycles, I've seen 'em go bad (to my frustration) in as little as a year or two. Luck of the draw you know. Let me know what you find

Edward

 

I just checked the voltage at 3,000 rpm with full load and it was over 13v. The only thing I can think of is the RS pulley at idle is below 12v and I was stuck in bumper to bumper traffic with the AC going for about and hour. Maybe the the abs, abd and check engine lights went on because of the slow discharging of the battery? The only thing that confuses me is that after the stop & go I went for another 45 to 60 minutes at highway speed and the abs, abd and check engine lights came on and off at least 5 more times. You would think that if the battery is getting over 13v the lights would stop coming on???

 

The car has been sitting for a few days with no trickle charge and it still measured 12.3v could it still be the battery?

 

Did ALL the dash warning lights illuminate kinda like a christmas tree or just the ABS/ABD related?

 

I dont remember all trhe lights, but I know abs, abd & cel. It looked like it did when the belt broke a couple years back but this time the lights would come on & off not constantly on.

 

Hi Tom,

I'm no expert, but what I've learned and found over the years is that the static, unloaded voltage of a battery is only one measure of a battery's health. Voltage under load is a more accurate picture of it's health --that and it's ability to maintain a charge. Moreover, a meter across the terminals tells nothing about how much of its capacity is available to you. I've had batteries in the past register over 12v static, and take a "full" charge (or so I thought), only to fail days later. I recharged it, all seemed fine, then days later again DOA. I surmised from those instances that the battery did not have 100% available to me, so when recharging I was recharging a battery of lesser potential. Then I read about plates sulfating which is an irreversal degredation of the battery's guts. Cest la vie ...that's what batt warranties are for! Since your Optima is under warranty, albeit prorated, you may want to try claiming in. Worth a try if all else checks out. Did you try checking the voltage with accessories on and revved up yet?
BTW, when my alternator croaked, I got the same christmas tree as you. I replaced the battery thinking that was the culprit as it was several years old. Then realized the next day (DOA) that my alternator was bad. So I do think your dash lights are an indication of something battery/alt related.

Edward