Voltmeter gone crazy!

[TheJMan]

It seems like almost all the time now, the voltmeter in my X jumps around. I mean it will go from 14 to about 16 and down to 10. It never seems to end, but sometimes it will hold at around 10 volts and I can feel the RPMs drop and the entire car bucks. The turn signals take forever to "click", and the lights on the dash and the headlights change with the voltmeter. Any ideas what's wrong? The battery is almost 2 years old, and has plenty of water in it, and the alternator was replaced on December 28, 2003 with a remanufactured one.

 

[Bill Kemp]

After cleaning the battery terminals I would take it to AutoZone or some shop to have the alt. tested. If that checks out OK test the battery. I think the voltage reg. is in the alt. so there isnt much that would cause the fluctuations other than bat. & alt., dirty term., bad battery cables.
I notice yours is first gen. & I seem to remember that there was some concern with the bat. cables going bad.

 

[TheJMan]

The battery terminals are pretty clean, every time I change the oil I spray some battery terminal corrosion protector stuff on there, and it has done its job.

 

[MrShorty]

It can be hard to say for certain that the battery cables are good from a visual inspection. In many cases, the cables corrode from the inside out. Best way to check battery cables is by measuring the voltage drop across the cable.

 

[Opera House]

The voltage right at the battery might be rock solid. This random problem can happen when the ground straps from the engine block to the body go bad. The voltmeter on the dash measures voltage from the + to the body. Try running a new #12 wire from the engine block to body and see if that cures it.

 

[ifixairplanes]

also check your big red wire on the back of the alternator, the one that goes over to the solenoid on the drivers side. that wire is what delivers the charge to the battery, if it is loose the symptoms you described will occur.

sean

 

[TheJMan]

Just took it to Checker and they tested the battery and said it was "toast". Anyway, they put in a new battery for only $20, as the last one only lasted a bit less than 2 years. Runs great now, no more gauge dancing around.