alternator going caput?

[GregCrabb]

I've had my '86 for 8 years now and slowly over time I've noticed when I first start up, the voltage will be kind of low on the meter but eventually go up to 12-13 as I drive. This week, my truck has seen more driving than normal, but tonight I noticed the meter is staying around 9-10 and NOT coming back up. I took it out on the bypass and went up to 70mph for a stretch and it didn't go to normal, moved up from 7-8 after starting to 9-10 but no higher. With the AC on it's pulling more juice but I've always watched it come back to normal at highway speeds. I'm thinking alternator since this has been happening over time, even when batteries were brand new it did this. Anyone second that?

When it rains it pours, window regulator gone out on my spare car, SRS light on in my TDI Beetle, still have that rear main seal leak (haven't had time to fix) on this truck and now probably an alternator. Oh well, at least they are all still drivable.

[JohnC]

I'd check the voltage with a different meter as the dash ones are not the best. Also, have the batteries individually tested as a bad battery will pull the whole system down.

[CleviteKid]

You have to watch some of the technicians at some places (who said SEARS ?? :rolleyes:) because they will NOT want to disconnect both batteries to test them SEPARATELY. I had a heated argument with such a tech over some batteries under warranty. Together, they passed a single battery test (duh !!) but separated, they were both bad.

Learned my lesson. Last time, I took both batteries OUT OF THE TRUCK and carried them into the store (not SEARS) and put them on the counter. Darned if they did not both fail the test when tested separately. :D

[argo]

If your alternator and batteries check out OK, check for a bad body ground. A bad body ground can drastically affect the voltmeter.

[GregCrabb]

Guys I just was thinking today (and I can't find the receipt anywhere...not like me, I usually put them in the glove box) My batteries are at LEAST 6 years old, maybe 7 even (time flies). Even Diehard gold batteries eventually go out. Truck is getting slow to start now so something is definitely pulling it down...working so much lately haven't been able to get out there to take them out for testing. Funny, batteries are more expensive than an alternator...at least in my location. Hopefully will be working on it this coming weekend...have to do that rear main seal too anyway, then I'm probably going to sell ( I hate to ) but I really NEED something with 4x4 or AWD capabilities. This old truck has served me very well for the last eight years, like the energizer bunny, it keeps going and going...

I just found my receipt...August 16, 2003 when I purchased the DieHard Gold's...I guess I've found my culprit.