89Ru Posted June 22, 2005 Share Posted June 22, 2005 Just finished a major repair which involved alternator removal and when I started up the dash voltmeter is running low. Have read good posts that suggest replacing the body ground (all my wiring is original ) Meter across battery reads 13V at idle, goes up to 13.6 at 2000 rpm. Slight (0.15V) increase if I measure voltage at the alternator (battery terminal to alt body) My '89 GL had its alternator replaced 2 years ago w/o problems so far and I took measurements of 14.24 volts at idle so I'm suspicious here...the belt is good and tight (if anything its too tight so maybe the bearing is getting hot?) Is the alternator overloaded or is running hot 'normal' (too hot to touch after a few minutes of idle) My non-stock fuel pump may be a power hog but other than that nothing should load it badly. Might there be a marginal short that doesn't blow a fuse - would have to be only when running (switched relay or otherwise) since the battery isn't dead. I might try a clamp-on current meter if I can borrow one Link to comment Share on other sites More sharing options...
Cougar Posted June 22, 2005 Share Posted June 22, 2005 Your battery may be low on charge or has a problem. I would suggest you have a load test done. Link to comment Share on other sites More sharing options...
mudduck Posted June 22, 2005 Share Posted June 22, 2005 Hvae a load test done. You battery might be almost shot. Do you have any aftermarket lights or stereo on when it is getting hot that quick? You should be able to touch it after just idleing for a few minutes. I have a stock alt. and I run a 200 watt "footwarmer" on my cb radio and it draws ALOT of power from the alt, but it takes a good while to get it to the point of where I can't touch it. Link to comment Share on other sites More sharing options...
89Ru Posted June 22, 2005 Author Share Posted June 22, 2005 Battery sat during a month of many failure-to-start cranking cycles (took me that long to correctly diagnose the problem) so it could be just doing a deep charge...or could have plates shorted together? (batt is a discount-store special, two years old, no abuse other than recently) the load test is a good idea, I'll do it before doing something drastic Link to comment Share on other sites More sharing options...
Cougar Posted June 22, 2005 Share Posted June 22, 2005 You should recharge a low battery using a charger. Using the alternator to charge a low battery puts undo load on it and can possibly damage it. Link to comment Share on other sites More sharing options...
89Ru Posted June 23, 2005 Author Share Posted June 23, 2005 Great advice. Jehovah Jirah. I come to find out that my neighbor has one of those commercial battery chargers. Put 20 amps in for 40 minutes, now the battery reads 12.5 volts. Manual says not to charge if the capacity goes above 75% (12.4V) or spits excessive gas Seems like the alternator was having a hard time with my low battery. Wooh. The more I learn the more I find out I don't know. Poor little alternator, she's not strong like Atec. Now I digress... Link to comment Share on other sites More sharing options...
555Ron Posted June 23, 2005 Share Posted June 23, 2005 Great advice. Jehovah Jirah. I come to find out that my neighbor has one of those commercial battery chargers. Put 20 amps in for 40 minutes, now the battery reads 12.5 volts. Manual says not to charge if the capacity goes above 75% (12.4V) or spits excessive gas Seems like the alternator was having a hard time with my low battery. Wooh. The more I learn the more I find out I don't know. Poor little alternator, she's not strong like Atec. Now I digress... Sounds like an excessive charge. I would be reading it its last rites and getting rid of it. Some of the cheaper batteries will fail quickly. Also, when leaving the car for extended periods the battery should be left fully charged. It might have a faulty cell which means the charger and alternator will work non stop to recharge it... though it never will. Link to comment Share on other sites More sharing options...
89Ru Posted June 23, 2005 Author Share Posted June 23, 2005 Sounds like an excessive charge. I would be reading it its last rites and getting rid of it. Some of the cheaper batteries will fail quickly. Also, when leaving the car for extended periods the battery should be left fully charged. It might have a faulty cell which means the charger and alternator will work non stop to recharge it... though it never will. Sorry to mislead, I was reading a quote from the manual, it didn't actually outgas. Powered up fine this morning at 14.24 volts just like its happy state before. Dashboard voltmeter was back at its normal level. Car got out of the driveway for the first time since May 20th. Brakes were rusty! but that was cured after a handful of stopsigns. Thanks for the overall concern. I will definitely keep an eye on battery health since it is listed as one of the worst performers Link to comment Share on other sites More sharing options...
Recommended Posts
Please sign in to comment
You will be able to leave a comment after signing in
Sign In Now