Alternator going out?

[Tobey]

Yesterday, I took a 200 mile road trip in my '00 Intrigue and half way into it I noticed my mileage display was flickering like crazy and I could hear whining through my speakers which varied with engine speed.

Today, I started it and the flickering and whining was gone. I put a voltmeter on the alternator and it's putting out 14.8 volts when cold, once it warms up it drops to 13.9v, which seems normal to me. I noticed it now squeals when I put an electrical load on it, but I suppose that could just be a loose belt.

Should I be worried? I plan to drive it to California from Colorado in the next 3 weeks, but now I'm kind of afraid to...

[phewop118]

13.9V is nothing to worry about, as the target voltage once a car is warmed up is usually around 13.8V. However, since you are getting flickering, have you replaced your alternator at all? The original ones tended to have issues maintaining a good electric field, causing voltage dips that would be noticeable with light flickering. Also, check your belt when you hear the squealing and see if you have a seized pulley somewhere or a bad tensioner.

[panzer dragoon]

Your voltmeter is stating an average RMS value, when the alternator field collapses you are running off your car battery 12.8v (lights dim, fan speed dips audibly). 15v-12.8V swings = voltmeter reads in the middle.

Notice it more in the winter when it is darker. Alternator electronics were updated and the new ones don't suffer from the field collapse issues. Swapping out the alternator takes a few hours, $140-180 for a new one.

[Tobey]

This is the original alt, and yes I get to experience the regulator reset issue quite often. But this is definitely something different though, the odometer looks like it's receiving some serious interference. The display is actually shimmering...

Today I managed to reproduce the issue by driving it for about 15 miles on the highway. The odo started flickering again and I could hear whining through my speakers.

I'm just gonna assume it is the alternator and replace the damn thing. It doesn't look to be that big of a job, like panzer said. And I'm afraid it's going to destroy my electronics if it's putting out really dirty power.

[panzer dragoon]

Changing that alternator may take all day. -take a good look at that and prepare yourself.

I have a 2000 Intrigue with a funky alternator -haven't fixed it yet, but I don't drive much in the dark either -mine actually got better or I just don't notice it as much.

-check/clean those battery connections also without killing yourself. Should be a noise filter for the radio also. A broken spark plug wire maybe throwing stray voltage all over.

[Tobey]

Well, today I got in and turned the key and it clicked and everything went totally dead. I opened the hood and checked fuses, while I was doing that I accidentally bumped the positive battery cable and the door alarm started dinging. After a huge sigh of relief, I tightened it down hard and all my problems went away. Flickering gone, whining gone, voltage is a stable 14.8 and the engine starts great!

I can't beleive it was just the connection, I already checked them a few days ago and they were tight and clean. Not tight enough, I guess. I ordered an alternator for nothing. Ain't that a bitch...

Thanks for the help guys! Guess you were right Panzer!

[panzer dragoon]

Those connections are lead = if you make it to tight they strip-out and they will loosen up. Clean off the corrosion, use some dialectric (conductive) grease, and tighten them down softly.

There are some battery terminal sprays available also.

[Tobey]

Dielectric is an electric insulator, it's non-conductive. But good idea, maybe I'll try to find some conductive grease to put on them.

[panzer dragoon]

"Permatex Dielectric Tune-Up Grease is a silicone dielectric compound used to insulate, lubricate and protect electrical fittings. It protects against salt, dirt, moisture intrusion and stray current in electrical connections.
Dielectric grease extends bulb and housing life of navigation lights, masthead electrical connections, trailer lighting and harness or any electric connections exposed to moisture and the elements. Prevents voltage leakage around any electrical connector thereby insuring a strong spark in high energy engine ignition systems."

-you made me think, but I always used it as a conductive grease and it always worked that way.