Golf Alternator or Battery?

We have a 1999 VW Golf, that had a dead battery the day before yesterday and required a jump. I put it on a charger all night and it still was dead in the morning. The battery (Interstate) is 16 months old. We jumped the battery & I put a Volt Meter on it and it read ~ 14.25 volts. We then took it to the Interstate Store and they put their "Wizard" on it. It was showing 12 volts with the car off.

They put in a new "loaner" battery, as their policy is to charge the existing one to try to find out if it is the battery. Then they measured the voltage with the car running with the new battery in and it was ~14.5 volts. I measured it with mine at home and it was 14.62 volts. The technician said the old battery showed signs of venting...acid from the vent on the battery case, and suggested that the alternator was possibly running too much voltage and could have "cooked" the battery. Incidentally or coincidentally, the right brake light bulb was burned out, something that happened in the last two days or so. This car has had a history of weird electrical problems.

The question is: is 14-5 - 14-6 Volts too high? My 2001 Jeep Wrangler reads 14.23 volts running, measured across the battery terminals.

Thanks for any advice,

Campbell Freeman South Carolina

Reply to
Campbell Freeman
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The spec. for the voltage regulator is 14V +/- 0.5V. Were the 14.25V and

4.62V measurements done at idle or at higher RPM? Try measuring with all electrical accessories turned off. Increase the engine sped gradually to about 3000 RPM. The voltage should remain within the 14V +/- 0.5 V. If not the regulator is not work>
Reply to
Randolph

General rule of thumb:

Battery at rest should read at least 12.45V

Battery with engine at an idle should read 13.5V to 14.5V.

Sounds definitely like a "bad" battery. The Interstate is not a great battery....

Reply to
Simplstupd

The measurement was done at idle. Will try at higher rpm.

Thanks very much.

Campbell Freeman

Reply to
Campbell Freeman

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