Low Voltage

[Brad B]

Just indivually charged both batts. with external charger. Cranks with good speed but it takes about 2-3 seconds for it to fire off. GP's seem to be firing ok but I haven't but an ohm meter on it yet. Dash gauge indicates very low after initial start up (below the N in "normal" on the gauge). While at idle the needle hangs about straight down with no load other than stock radio. At nite, needle reads between "N" and "O" with low beam headlight and low speed AC blower running. Hardly any difference with the blower off or without the lights. Reads more towards positive at around "R" or "M" with the engine revving around 1500-2000.

Alt. new about a year ago I think (have to check the records). Terminals are clean and tight. Cables are in good shape as well.

Any ideas?

 

[DaveBen]

The only way to tell is to use a volt ohm meter. Get a cheap one at Radio Shack and test it. The alt will not come on line immediately after starting and that is normal. It takes about a minute or two, so don't panic. Good Luck.

Dave

 

[Brad B]

I realize that the alt. doesn't come online for a while after the initial start. That's not my question. The problem is, that the gauge reads n the negative range at idle and only comes up to about mid range when RPM's get to around 1500+. Sorry for any confusion in my initial post.

According to my battery charger that has an alternator test function, it test good.

 

[95_stroker]

How old are the batts?

 

[Brad B]

Had the system checked by mechanic shop last June. They replaced one batt. at that time.

 

[95_stroker]

Youve gotta replace the batts in tandem, if one of your batts is weak (Old) it will soon kill the new batt.

 

[dzl_x_4x4]

I had the same problem. The best way to test the batteries is to leave your doors open/interior lights on for a afternoon, then try to start it. Mine would start and hold enough of a charge to start again, but if I left my doors open it would kill the batteries in a few hours, even with the 2 batteries. If I would put a charge on it, they would last for a month and then I would have to re-charge them. I also had mine tested last year and replaced the alt. and again this year. I think because the alt. tried to keep the batt's charged.

 

[Brad B]

I had the same problem. The best way to test the batteries is to leave your doors open/interior lights on for a afternoon, then try to start it. Mine would start and hold enough of a charge to start again, but if I left my doors open it would kill the batteries in a few hours, even with the 2 batteries. If I would put a charge on it, they would last for a month and then I would have to re-charge them. I also had mine tested last year and replaced the alt. and again this year. I think because the alt. tried to keep the batt's charged.

That may be the ticket. While I had one batt. disconnected and charging, I played the radio and it only lasted about 2-3 hours and it completely killed the battery. Not even enough left in it to light up the clock.
Guess I'll go get two new batteries !! Thanks