I have a 25watt Alpine head unit that the display dims on with every heavy bass beat(basically flashes along with the beat)
even when the truck is on (battery charging)

I have 6x9 140 watt's in the back and original 6 1/2's (20 watt) in the front. The more I turn it up, the more noticable the flashing is.

The stereo seems to work fine....What is going on?

Matt
1978 F250 4x4 - 351M
Don't crush them, restore them!

 

You are taking more power from you truck's radio circut thatn it was origianlly rated for. There are a few things you can do. You can re-wire the stereo so that the constant power line to the radio goes straight to the battery. You can purchase a larger battery or alternator or both, or you can but a large capacitor that would fuel an amplifier during surges of power. Or, you could just leave it. My Bronco did it for 2 years, even with the battery, alternator, and Capacitor.

Good Luck

Murph

 

Battery, Alternator, or a cap will not help this condition your speakers are asking for more than your deck can give them the only way you could solve this is to put your high watt speakers (the 6x9's) on a small amp or just leave it as it probably wont hurt anything

 

Hi
It sounds to me like you have the deck illumination lead hooked in with the power leads (on Alpine I beliieve it is orange).
An illumination lead is hooked into your dash light curcuit so that when your dash lights come on your deck display dims. Why? Well it is because during the day your display needs to be bright so you can see it and at night when your head lights are on the display does not need to be so bright to be seen. What would be happening in this case is you deck needs the power to make the bass audible and is robbing the power it needs from the display. If this is not the problem , let me know. I'll try to respond but my computer recently caught a bug.
tonka