Is It My Battery Or Alt.

[Rosedog]

alright this is a weird one. i am out tonight and while on the freeway I noticed that I was in 3rd gear vs. drive. I made the shift into drive and noticed that my headlights got brighter. I quickly look at my voltage and saw it come up from below the mid mark (14) to its normal position. this scared and intrigued me. I decided to test this again and when I accelerated in 3rd my voltage would start to go down (WTF!). I already had my alt replaced a few months ago. Could it be my alt, battery or what?

[pm26]

If you got the replacement alternator at Auto Zone, it is probably bad. Defective voltage regulator, causing erratic voltage output. Attach probes of a direct voltage meter on he battery terminals. The voltage should be about 12.5 to 12.7 volts for a fully charged battery. Record the voltage, then start the engine and read voltage again. You should see 13.5-14.5 Volts. Rev up the engine and see if the voltage changes. If yes, you most likely have a defective regulator. Note: Switching on accessories that use a lot of current could cause a temporary voltage drop. Do this test without turning on accessories such as lights or A/C.

[svensk]

If you got the replacement alternator at Auto Zone, it is probably bad. Defective voltage regulator, causing erratic voltage output. Attach probes of a direct voltage meter on he battery terminals. The voltage should be about 12.5 to 12.7 volts for a fully charged battery. Record the voltage, then start the engine and read voltage again. You should see 13.5-14.5 Volts. Rev up the engine and see if the voltage changes. If yes, you most likely have a defective regulator. Note: Switching on accessories that use a lot of current could cause a temporary voltage drop. Do this test without turning on accessories such as lights or A/C.

Yeah, your engines sucking more juice in 3rd than OD that's for sure.

[Rosedog]

If you got the replacement alternator at Auto Zone, it is probably bad. Defective voltage regulator, causing erratic voltage output. Attach probes of a direct voltage meter on he battery terminals. The voltage should be about 12.5 to 12.7 volts for a fully charged battery. Record the voltage, then start the engine and read voltage again. You should see 13.5-14.5 Volts. Rev up the engine and see if the voltage changes. If yes, you most likely have a defective regulator. Note: Switching on accessories that use a lot of current could cause a temporary voltage drop. Do this test without turning on accessories such as lights or A/C.

Yeah, your engines sucking more juice in 3rd than OD that's for sure.

 

 

Its never done this before either. Maybe it is a bad voltage regulator.

 

As for my Alt. being replaced, I had that done by the dealer. I'll start by taking it back to them either tomorrow or monday.