How did you know that your alternator was dying?

[speedoflife]

For those of you that did not get stranded on the side of the road when your alternator suddenly stopped charging, how did you know it was about to give out?

My charging system has been fluctuating from 13-14 volts and dips into the 12's occasionally. I know there is a good amount of fluctuation naturally present in a charging system, but even during highway driving it's all over the place. The dips in voltage don't seem to be related to current draw (lights, A/C, etc. all off during random drops). I can visually see my lights (headlights and dash) wavering during idle and sometimes driving.
I'm thinking my alternator is on it's last legs, but I want to be sure before I pull it out (it only has about 25k miles on it).

 

[Huachipato]

The one time it left me stranded - I was on the highway and thought it odd that my radar detector as indicating less than 12V. I thought it a fluke. I had driven over 100 miles without an issue. But the battery finally ran out of juice and the car died rather suddenly on me. It started with the dash flickering different lights at me (ABS, SRS, Brake) and then quickly moved to loss of power. In this one situation - I was too stupid to see the signs before it was too late. I did manage to put the car in neutral and coast off the highway and into a parking lot - car was dead.

In that same trip - my resolution was to get a new battery in the car and drive the rest of the way home. About 30 miles. It worked out alright for me. But since then - I have added the Aeroforce gauges and always keep a keen eye on the voltage.

The more recent time the battery light would start to come on when the car was idling on a warm engine. Aeroforce gauge confirmed the low voltage readings. Trickle charging the battery every night bought me a few days to get the parts I needed. Swapping out the alternators quickly corrected my issue this second time.

 

[nxhappy]

auto parts store can test it ...

 

[2011 gtcs]

I noticed at night my gauges would start to dim, than I checked voltage and it was at 13.1 volts. So I knew it was done.

 

[Black02GT]

Like mentioned above usually see the idiot lights flick on and off, headlights dim and with HIDs eventually cut out right before you coast to a halt. If you have a tuner, log one of your next trips and check out the min values. When mine were tired you could load the alt and get it in the 11 volt range at idle.

Fun story, one time I was alerted by a electrical burning smell. Internal regulator shit the bed I suppose and with my overspun alt. was making 14 volts and idle and 15 volts at 2,000 rpm. Happened on the way home from my friend's after putting in my TKO Magnum if its not one thing, it's another.

 

[speedoflife]

Well thanks for the information guys. Will an auto parts store bench/load test your alternator for free?
At the same time, it's always simply a matter of time before the alt. goes out, and it sounds like it will happen suddenly. I think I might just get it rebuilt to prevent it from going out completely.

 

[Bdubbs]

I noticed my alternator was going out while watching volts on my aeroforce gauge.

 

[speedoflife]

I noticed my alternator was going out while watching volts on my aeroforce gauge.

How low was it dropping at cruise and/or idle? What range was the voltage in?

 

[Bdubbs]

How low was it dropping at cruise and/or idle? What range was the voltage in?

I'd watch it religiously and it was always in the 13.3-13.8 range once everything was up to operating temp. When it started going south it was good in the 12's and as low as 11.9 for a little bit.

 

[speedoflife]

I'd watch it religiously and it was always in the 13.3-13.8 range once everything was up to operating temp. When it started going south it was good in the 12's and as low as 11.9 for a little bit.

Thank you for letting me know. I've been watching mine like a hawk lately - I'm nervous of getting stuck on the side of the road.

 

[Bdubbs]

Thank you for letting me know. I've been watching mine like a hawk lately - I'm nervous of getting stuck on the side of the road.

I said good in my last post, but it's not letting me edit. I meant to say, when it started going south it was reading in the 12's. I recently went with a nations alternator which has a external regulator.

 

[Comp04svt]

I had just gotten an areoforce gauge beginning of summer and right off the bat when it was warmer outside I was seeing as low as 11.7 volts. Voltage on mine would never get higher than 13.5 volts even from a cold start, and will continuously drop as the engine warms up. 60 degrees and under outside I see 12.8 ish max when the engine is warm. Don't know how long I've been having this cause I just got the gauge this past season, but before mine comes out of storage I'll be doing an alternator lol. Ill be going with a Justin Wheeler 200a FYI.

 

[SID297]

Had one rebuilt a couple weeks back that was making quite a bit of noise and had to be spinning pretty hard to make proper voltage.

 

[quad]

A few years ago my 2 year old battery would run flat often and one night we barely made it home and the car died right at the top of the driveway. Fortunately I was able to push it back in the garage. The warning signs were there - flickering lights etc.

I took it to Alternative Auto and the issue was quickly resolved. Turns out my dumbass got into the habit of disconnecting negative quite often on the battery and never tightening the terminal properly when reconnecting it. I just became too relaxed about it. It failed to make a proper connection and the battery consequently ran flat since I was driving around with a loose connection. I was so pissed at myself!

Now I connect a trickle charger if the car is going to sit for a while instead of just disconnecting the negative terminal.

I also keep an eye on the voltage with my Aeroforce.

 

[hotcobra03]

Just posted in engine section..

I'm installing alt now..

Radio going off and gages sweep..

My volts are all over 10.5 to 14.4

When below 12 radio goes out
Below 11 car shuts off

It will restart as your driving..backfire than at any time do it again

 

[P49Y-CY]

the first thing i noticed was that the car would not go into boost. i was on my way to work. then, as i got closer to work, the radio and lights started doing weird things. and by the time i got to work, it died. i just barely made it lol

i am convinced what killed mine was the wrong size (too tight) belt for my pulley. i think it was too hard on the bearings. i think it is important to keep the tension indicator right in the middle or on the slightly looser side.

but my other car (bought it new) has 120k, and still on the original alternator.

 

[RI-SVT]

I have a spare stock alternator, I'm planning to have rebuilt with higher amperage to try out first before I look into a aftermarket option.

 

[hotcobra03]

After my install found out mine wasnt alt causing issue.


Ground wire from battery to radiator support was broken inside..

I found it going around and rechecking connections..i did a wiggle test when i pulled all 12v grounds and positive to clean..

I pulled a little harder and wire broke in half...

With a new wire im seeing 14v with everything on..

Its always been 13 to 13.5 inside car reading volts vs battery 14 plus

 

[mr. b_98GT]

I ordered a Ford Reman Alternator, part # 2R3Z-10V346-BDRM, recently because of some fluctuations with the voltage. It is an upgraded 130 amp alternator. Price with a $75 core charge and shipping from Autonation Ford White Bear Lake (Tousley) was cheaper than my local Ford dealer by a long shot. Paid $207.57 + shipping (ordered a few other things). I don't know if I'm going to send the core back, might keep it and have it rebuilt to have a spare in the garage.

The old alternator is still running good, but when I first start the car, the voltage will sometimes start out at around 11.4-11.7, and once I rev the motor a bit, it moves to 14.1-14.2. It will also sometimes just start and read 14.1-14.2. I did notice a couple of times in the last few months that the voltage would drop if it's idling in a parking lot, but it jumped to 11'ish and jumped right back up into the 13's. While driving, the voltage stays between 13.4-13.8, and there is no flickering of the lights or any other signs yet. Battery is new. I've been watching the voltage closely as a I drive the car, and I'll probably swap out the alternator soon just to be on the safe side.