is this possible on an SC400? when i stop on a rainy cold day say at a light, and my heat is blowing, my heated seats are on and my wipers are going as well, my dash lights really start to dim. the lights also dim every single time i use the wiper on a single wipe, or if i'm lowering or closing the windows, or moving the seats. i had my alternator checked at autozone when i got a new battery but they said it's good, and my battery reads 14+V when the car is running.

i'm not sure what it could be, maybe the wiring? i'd like to stay away from replacing the alternator since they're not that cheap so hopefully i can find the issue somewhere else. any ideas?

 

Do they dim when you have the radio on as well?

It sounds like you want to draw more power than you can. Audio guys use a capacitor to help, which in this case may be all you need. Other options that I know of are a second battery, larger battery, alternator with more output current/power. It is just odd that you would have to take these steps for stock items such as wipers and headlights.

Stock seat heaters? radio? Could be an okay alternator, but with all the accessories and the age of the alt. .it could be less effective,

Sub'd to see what others say about any odd issues.

 

i just now installed some amps, but they're low output and it was happening before the installation. before that i didn't even have a radio. i think the alt is just old and needs to be replaced even though autozone tested it fine.

 

Well enjoy the new tunes.

I would think you are correct. I don't know if they test the current it can output, but just the voltage which with 14V sounds okay so I would see if someone local may rebuild them.