Heres my problem: The voltage is usually just above 13 on the guage. However when I put the windows up or down the voltage drops to 8 but goes right back up when I let off the buttons. When I turn my headlights on the voltage drops to 8 and my lights inside and out get very dim, voltage stays down for a few minutes then jumps up and my lights get bright. Few minutes later voltage goes back down, and then will go up. My lights continually dim and fade dim and fade. Anyone had this problem or no a spot to start trouble shooting? Any help will be appreciated. THanks

 

I know nothing about cars, but sounds like something is wrong with your alternator.

It seems that it is making the car rely more on your battery then it kicks in, and keeps going back to battery, back to alt. etc.

 

you either have a ground problem....check ground straps on engine to frame.
or your voltage regulator is failing to keep the battery fully charged when a load is placed upon the system

 

If you have a meter that measures voltage check the voltage at the battery cable ends with .....

The engine Running.. accell engine one time and then let idle ... check the voltage at the cable ends. Should be between 12.8 - 14.2 volts and stay steady. If not replace alternator.. if it does ...

Have someone duplicate the problem with the lights and check the voltage. Voltage should never drop bellow 12 volts with the engine running and the lights on. if it does.. make sure the cables are clean if ok... Replace alternator.. Might wanna check the battery too...

Shut car off ... battery voltage should be about 12.4 volts.. Have someone turn over engine while you check the battery voltage at the cable ends while cranking. Should not drop below ( or not much below ) 9.8 volts. If it drops much bellow this the battery's bad....

It's not unusual for the power windows to show a major voltage drop on the gauge. They draw a lotta ampreage, especially when the window motors get older.

 

I just bought a new optima yellow top battery about 3 months ago, I hope it isn't he battery, htey run about $200.

 

Probley isn't the battery anyway.. I just basicly gave you a complete charging analysis there like I might do on what's called a VAT's tester at work. Your using the car to put a load on the battery instead of the VAT's tester is all..

 

Im having basically the same problem, but my lights are dim and flicker, and the headlights get brighter when i step on the brake. I was thinking maybe its my tensioner cause it makes alot of noise so i need to replace it but though that the belt was slipping on the alt, causing voltage drops maybe.

 

ever find out what was the problem?