alternator problems
 

I have a general question about alternators. I have had the same daily driver a 1986 El Camino since 1991. Back in the early 90s my first alternator failed. I bought a AutoZone lifetime warranty alternator. They seem to last about 6 years, but replacements are free. My last alternator worked fine once you hit 2,000 RPM the first time. After that, even at idle it ran 13.5 volts. As it aged it got to the point I had to hit 2,500 RPM to get the alternator to start to charge.

I swapped the alternator which only takes 20 minutes and the new one is really strange. Sometimes is charges sometimes it does not. Yesterday going to lunch it did not charge. On the way back it was fine. This morning on the way to work it jumped to 13 volts after startup. Half way to work it stopped charging.

I double checked the grounds last night. The battery is one week old. Obviously a part time alternator is not acceptable. Should I just go demand yet another alternator or it there something I am missing?

Is the voltage regulator internal to the alternator? Seems like that is where the problems are.

Usually an alternator that doesn't start charging (bootstrap in Alternator parlance) is due to a faulty field exciter. In our 911's the alternator lamp did that. I the voltage reg is external start there. Maybe also look for a loose connection or flakey connection to the exciter.

Your Elky's alternator is internally regulated. As you've checked the battery cables, I'm assuming that includes the cable and wiring to the alternator. The regulated is very likely flaky. When these are rebuilt, only the parts that are worn are replaced. If the regulator is replaced at all, it is tested - if good - then it's done. If it's reused, again it's tested once - if good - then it goes into the alternator.

Yes, get a new one. The argument will start when they test it and the "flaky" is working at that moment... Their contention will be that there is something wrong with the car (battery, wiring, ignition, etc). Make absolutely sure that nothing is causing a poor or intermittent connection to the supply voltage for the alternator. The connector at the alternator goes bad all the time. It's a piece of plastic crap and you can usually replace it for about $1. This is an 86 - it probably is beneficial to replace this item even if the issue proves to be the alternator itself.

angela

Put on your best pissed off face and go demand a new one... Hell are they open after 5? I'm gunna be up there early tonight I'll go do it for ya...

I stopped at AutoZone at lunchtime. They stuck the tester on and it showed failed. So no problem with getting a new one. On the way up there it was showing 13.25 volts but when I restarted it for the test it was not charging. On the way back it was charging.

I will swap in the new one tonight.

Just let everyone know.... Glen got his new alternator in and I verified the quality of work. :D It fired up charged and we went to a PCA meeting....

Yep the new alternator was the cure. It instantally goes to 13.2 volts and stays there.