Strange alternator issue

[gmcman]

I call it strange because generally I have an alternator just crap out or have sometimes just have low output.

I left work Monday and I had the 'Alternator not Charging" warning on the DIC. I went out and the positive cable was not loose but I could force it slightly so after that it was fine. The cable was tight but I did snug it some more.

All week it was fine but tonight I lost the alternator but it came back on sporatically. I haven't had one act like this and makes me think of a loose connection but they are all tight with no corrosion that I can see.

Battery is tight, cables are tight, do these alternators have a history of this when they are fading out?

Battery is Optima Yellow top and is 5 years old. the alternator is the original with 175K miles.

I have never had a hint of electrical problems, makes me think the alternator is suspect.

 

[CaptainXL]

Try replacing the battery bolts. Just replaced mine and found they were corroded inside so you can't see. Remove the old bolts using a flat blade screwdriver and then pull off the black and red boots. Then use a wire brush and some ammonia to clean off the lug terminals. The bolts are $2.50 at autozone. Its a good first step.

Also, your battery is getting up there. Would recommend you replace it just as a preventative maintenance thing.

If neither of those work I would start looking into getting a new alternator. That is if the wiring checks out.

Edit: while the age of your battery has me the most concerned I have read that Optima yellows last quite a while. If it's not a connection and your getting in and out voltage then the alternator would be a good bet.

 

[Wooluf1952]

The alternator is a PITA to R&R, so if it's close to time for a coolant, t-stat and coolant temp sensor change, now would be a good time.

 

[northcreek]

An intermittent alternator problem can also be caused by it's brushes near the end of their life or hanging up in the holders.Also a bad belt or tensioner can cause slippage,there is more load on the alt/belt connection than most people realize...Mike.

 

[Mooseman]

Mine did the exact same thing, 2 or 3 times before it finally gave up the ghost completely. Time for a new alternator.

 

[gmcman]

The alternator is a PITA to R&R, so if it's close to time for a coolant, t-stat and coolant temp sensor change, now would be a good time.

I agree, however I had just changed the T-stat, ECT, and coolant earlier this year.

I should have changed the alternator or had it rebuilt just for the fact of the miles on it

Try replacing the battery bolts. Just replaced mine and found they were corroded inside so you can't see.

I am going to pull the cables off today, ran out of time yesterday.

 

[gmcman]

Well, at least I believe I have found the problem. Battery terminals were clean, I wiggled and reseated the signal wire....all is good. Was low on volts and when I moved the wire the motor loaded up.

We shall see.