alternator problems 86 240???

[RandomRiot]

About a two weeks ago all the idiot lights on the dash started flickering on and off, then the radio started losing power. Finally last weekend it was having a hard time starting. It would start with no problems if it was sitting for several hours but if i were run it for awhile, stop and then try to start it up again, it would take a while to catch like the battery was dead. I assumed it was the alternator thinking that the battery was being drained after useage not leaving enough juice to start back up.
I bought a battery/alternator tester from Radio Shack which told me my battery was low and my altenator was fine. Replaced the battery and it ran fine for about 3-4 days. Now I am having the same problem again. After usage it is having trouble starting back up. I replaced the alternator 7 months ago, it was done by a auto shop and they used a 'rebuilt alternator', which probably means that it came from a junk yard.
Does this sound like the alternator is dying again or could it be something else?
Thanks

[dpauto.com]

without a proper test on the charging is hard to say. Sounds like a bad alternator. Could also be bad wirings.

Dave

[Guest]

My volvo (85 240) is doing the same thing, exactly how you discribe. Have you figured it out yet? I would like to know what the problem was with your car...thanks in advance. -Aaron

[baba-booey]

Check the ground wire for the alternator - these constantly get abused by dripping hot oil and crap from the road coming up if your belly pan is missing. My '79 reqires this connection to be done every 2 years or so. the radio is usually the first thing to malfunction at the lower voltage.

[Arete]

Just went through the same thing with my 81 245. After 2 alternators, the mechanic found it was ground wires. I could drive for up to 60 miles and then it would be completely dead. I plan on installing a volt meter and an ammeter. Don't like driving blind.