Big Voltage Drop with AC on?????
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From: Cypress, Tx (Houston)
Big Voltage Drop with AC on????? Ok - so it's a nice day and I'm driving my car. Voltage gauge reads over 13.
Bang - it gets hot outside. I kick the air on while running down the road. Voltage doesn't change much. Red light. I stop. Voltage begins to drop SLOWLY down to maybe 12. Green light. I take off and the voltage climbs SLOWLY back up.
Battery & Tensioner are new, like 3 months ago. Alternator is new, like six months ago.
Any guesses?
Bang - it gets hot outside. I kick the air on while running down the road. Voltage doesn't change much. Red light. I stop. Voltage begins to drop SLOWLY down to maybe 12. Green light. I take off and the voltage climbs SLOWLY back up.
Battery & Tensioner are new, like 3 months ago. Alternator is new, like six months ago.
Any guesses?
Pretty normal. The blower motor is the biggest single draw on your electrical. AC comp on + fan on high will cause exactly what you are seeing. I have an Optima, new alternator, and have done the big 3. Normal. Only way to combat it is to get a HO alt that is wound to give good output at idle.
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Originally Posted by 2MuchRiceMakesMeSick
In the past 6 months you have replaced the battery, altenator, and the tensioner. Why?
Changed the alternator (warranty) a couple weeks after I got the car - lights were flickering (dash lights, headlights, all of them). Dealer diagnosis was bad alternator - they replaced it. Flickering lights were cured.
Was fighting the dealer on some warranty items and had the car checked out by another shop. They spotted a bunch of sprayed on gooey lube on the back of the tensioner (so THAT's where the squeaking is!) and they found the battery to be crap. Armed with my data the dealership caved in a replaced those (along with a bunch of other crap).
Originally Posted by 2MuchRiceMakesMeSick
Voltage in terms of your altenator charging is realitive to your rpm. It charges the least at idle.
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Originally Posted by jmilz28
Pretty normal. The blower motor is the biggest single draw on your electrical. AC comp on + fan on high will cause exactly what you are seeing.
Originally Posted by jmilz28
Only way to combat it is to get a HO alt that is wound to give good output at idle.
