volt meter issue

[Zwoof]

my voltmeter (in dash) will be holding steady at 14 then drop to 12ish then it will go back to 14, I drove most of the way home today and it was sitting on the low end...I tested the battery with the engine off and it was 12ish (my meter scale is small and hard to read exactly) With the engine started its reading 14 (even though the in dash volt meter is reading low)

I started it again and this time it was reading 14 again..The batery terminals are clean and tight and the car runs well....Any Ideas? Thanks in advance of any replies

[j cAT]

Originally Posted by Zwoof

my voltmeter (in dash) will be holding steady at 14 then drop to 12ish then it will go back to 14, I drove most of the way home today and it was sitting on the low end...I tested the battery with the engine off and it was 12ish (my meter scale is small and hard to read exactly) With the engine started its reading 14 (even though the in dash volt meter is reading low)

I started it again and this time it was reading 14 again..The batery terminals are clean and tight and the car runs well....Any Ideas? Thanks in advance of any replies

I would look at the back of alternator and make sure all connections there are clean and secure and measure at this point with meter for voltage of 14.25 with engine running.....if your alternator has a connector with small wire remove and inspect as these tend to get corroded...

[drdd]

12V with a voltage tester is too low. It should be 14V without the truck running

if your dash voltmeter flickers or jumps down and then up, it could be your belt tensioner needs replaced --- easy to do and cheap!

Originally Posted by Zwoof

my voltmeter (in dash) will be holding steady at 14 then drop to 12ish then it will go back to 14, I drove most of the way home today and it was sitting on the low end...I tested the battery with the engine off and it was 12ish (my meter scale is small and hard to read exactly) With the engine started its reading 14 (even though the in dash volt meter is reading low)

I started it again and this time it was reading 14 again..The batery terminals are clean and tight and the car runs well....Any Ideas? Thanks in advance of any replies

[Spectria, L1 MT]

Originally Posted by drdd

12V with a voltage tester is too low. It should be 14V without the truck running

if your dash voltmeter flickers or jumps down and then up, it could be your belt tensioner needs replaced --- easy to do and cheap!

In a perfect world, the voltage at the battery should be 12.7 at rest, engine off. If it has 14 volts, that would be very strange as the battery is rated at 12 volts, actually 12.7, or about 1.265volts per cell.

State of Charge Voltage12V
100%1.265
75%1.225
50%1.190
25%1.155
Discharged1.120

Good luck reading the chart I posted, this forum doesn't format cut and paste.

Charging voltage should be 13.6 to 14.2 volts.

I am not sure with the electronic dash, but poor grounds for the cluster used to cause flickering gauges and incorrect readings with many vehicles, including my 94 jimmy with electronic dash.

Also alternator brushes worn to the end of their life (at the end of the spring) often cause varying outputs.