Amp gauge reading too high, car runs normally.

[hursst]

Hello,

   I have a '74 Camaro Z-28, all stock.  When I started it this morning to try to drive about 100 miles to a VCCA show, I noticed that my Amp gauge was reading around 25 and up to 40 when revving the engine.  I gave it a 5-minute test drive to see if it would settle down any and it went to about 20 and stayed there.  The car ran fine the whole time.  I didn't want to risk the trip, so I went home. 

 

   Battery test revealed about 12.8V, which is good.  Alternator test revealed about 13.9V at the battery when car was running, which is expected.  However, the Amp gauge read about 19 when the car was running at this time.  The battery is about 7+ years old.  Any ideas on why my Amp gauge is reading so high when the battery seems to be reading as expected?

 

-Chris

[TerryB]

You are getting normal voltages so that is good but not the whole story.  You need to get a load test done on the battery to see what it amp output is.  The amp gage is showing the battery may have issues with delivering enough power to keep everything running.

 

Terry

[hursst]

Terry,

  Thanks for the advice.  I do suspect the battery, since it's over 7 years old.  I usually average 6-7 years on a battery, so I'm on borrowed time. 

 

-Chris

[TerryB]

Item, old batteries can be a problem.  You have a great car, one of my favorites.  In 1983 I bought a new z28, red, 5 speed, 305.

Terry