Lights Flicker

[kconnor]

Did a search on this but did not find a definitive answer. The inside and outside lights on my son's 95 ATX flicker. It has a new battery and alternator which were replaced at different times. Pep boys replaced the alternator a week ago under warranty, but this did not happen with the old one before it went bad. All the cables and connections appear to be clean and secure. I noticed that the voltage at the battery terminals is about 14.1V with lights and accessories off and 13.0V loaded. It also fluctuates about 0.175V - 0.200V. Seems like a lot for a regulated supply. Any input is appreciated, thx.

 

[shoshirtsandhat]

Swap alternators,or bench test the new one1...I hope it helps man...Joe

 

[Storm-Chaser]

Have the alternator tested [again].

"Flickering" is usually a sign of a bad voltage regulator . . . .

 

[Eric VerValin]

Or a loose belt... Your voltage drop sounds ok too... see if maybe you might be able to take it to a shop who rebuilds them and have them test it versus an Autozone or something. They can tell you better whats going on with it, versus, a simple pass or fail light.

 

[kconnor]

Thanks guys. I had a feeling it was the alternator but since it is a week or so old I wasn't positive. I'm not sure how valid a check this is but with the engine off and the lights and accessories running off the battery the lights burn steady. Pep boys service was kind of aggravated when he brought the car back to get a new alternator under warranty. I know they are really going to break his balls this time. I can hear it now, "It got to be something in your car that frying them".

 

[Storm-Chaser]

And I've been trying to get AutoZone to warranty their piece-of-shit battery that won't hold a charge, since February. I believe these fall under the [stall until it's out-of-warranty] "looks good to me" testing procedures.

The last time I went in, the AutoDrone ***** stated, "see, it tests fine!"

That's was until I pointed out to him, that the placard on their testing cart indicated my battery had failed the test and needed replacing, to which he then replied, "well, ah . . . , I guess we need to charge it and retest. That will take at least and hour . . . .".

He was kinda surprised when I stated, "I'll wait . . . ."


Here's to you, AutoZone . . . .

 

[Storm-Chaser]

Go to Advanced Auto, if you have one nearby. Most of their stores now have alternator/battery testing equipment that also provides a printout of whether the alternator/battery passes/fails the test(s), as well as why.

A bad alternator and/or faulty voltage regulator that results in low output, will generally result in hard-to-start or needs-a-jump-start situations during short trips (the alternator does not have time to recharge the battery-drain from the initial start). A faulty voltage regulator that results in high-output will result in occassional "bright lights" periods where the headlights and interior lights appear much brighter than normal. A voltage regulator that cannot control output, will result in the "flickering" you described, as it cannot maintain voltage within either the high- or low- limits of the system (~13.5-to-14.5 volts).

If you do a "search", you will find a number of threads on dead-out-of-the-box, defective-out-of-the-box, and failed-shortly-after-installed posts for alternators and batteries. So your case is by far from being an "isolated event" . . . .

Thanks guys. I had a feeling it was the alternator but since it is a week or so old I wasn't positive. I'm not sure how valid a check this is but with the engine off and the lights and accessories running off the battery the lights burn steady. Pep boys service was kind of aggravated when he brought the car back to get a new alternator under warranty. I know they are really going to break his balls this time. I can hear it now, "It got to be something in your car that frying them".

To which you reply, "Nope, it appears it's your piece-of-shit parts that's the problem. If you have a problem with that, I'll be more than happy to take this discussion to your district manager . . . ."

 

[kconnor]

I always thought that a lead acid battery needs at least 2.25V per cell to properly float charge. That's 13.5V, this thing drops to 13.0V with the lights on and the blower motor on max. The voltage jumps around a couple of tenths too. My car, also a SHO is rock steady. If I recall correctly most of the cars I've measured over the years were at 13.8V under load. I guess the only way to be sure is to take it to Advance Auto and let them check it out. It might be marginal but still good enough to pass a test.

 

[kconnor]

It was the alternator. The Pep Boys mechanic who changed it out said it is very unusual to get two bad ones back to back like that. He hinted that someone probably tried to repair the first bad one and threw it back on the car.

 

[Storm-Chaser]

Realize that most stores are reluctant to simply change-out a warranty item, as it represents a "hit" on their daily store revenue.

On my slightly related story above . . .

I took it by again for testing this week. With the colder temps I've had to get a jump as often as twice a day. Leaving the radio or lights on for more than a "few" minutes and it needed a jump.

Well, to make this long story short, they tested it this time and I watched as the battery voltage dropped to 5.88 volts during the simulated "starting" test. Their damage machine FINALLY came back with "BAD BATTERY".

I now have a new battery, and the starting issues no longer are !

:woo-hoo:

And I've been trying to get AutoZone to warranty their piece-of-shit battery that won't hold a charge, since February. I believe these fall under the [stall until it's out-of-warranty] "looks good to me" testing procedures.

The last time I went in, the AutoDrone ***** stated, "see, it tests fine!"

That's was until I pointed out to him, that the placard on their testing cart indicated my battery had failed the test and needed replacing, to which he then replied, "well, ah . . . , I guess we need to charge it and retest. That will take at least and hour . . . .".

He was kinda surprised when I stated, "I'll wait . . . ."


Here's to you, AutoZone . . . .