Battery amperage

Tiny
ZEMORZEMOR
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  • 2000 MAZDA PROTEGE
  • 1.6L
  • 4 CYL
  • FWD
  • MANUAL
  • 174,000 MILES
I hooked up amp meter clamp on the positive battery cable. The clamp did not read zero amperage?

i hook up to another car at idle with headlights on and ac on it read 44 amps.
Sunday, July 10th, 2016 AT 3:44 PM

6 Replies

Tiny
WRENCHTECH
  • MECHANIC
  • 20,758 POSTS
That is right. It will only read amperage if current is being pulled from or put into the battery.
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Sunday, July 10th, 2016 AT 5:01 PM
Tiny
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When I hooked up the clamp the car was running with the headlights on, but no amps. I am confused.
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Sunday, July 10th, 2016 AT 5:50 PM
Tiny
WRENCHTECH
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The headlight were taking out and the alternator was putting in. They may have balanced out. The only other explanation is you were just using the meter wrong.
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Sunday, July 10th, 2016 AT 5:52 PM
Tiny
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I hooked up the clamp at the positive battery cable coming from the alternator.
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Sunday, July 10th, 2016 AT 6:14 PM
Tiny
KHLOW2008
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Try adding the electrical load or lowering it to see if there are any differences. Eg, turn on A/C or off the headlights
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Friday, July 15th, 2016 AT 8:04 AM
Tiny
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There is no difference when I turn on headlights
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Saturday, July 23rd, 2016 AT 6:48 PM

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