Dimming lights-is this normal?

[DblA]

While driving in my new-to-me 2001 SR5, I noticed that the head and dash lights dim at idle. If the heater is on, the blower backs off a lot too. When I step on the gas, everything gets brighter. It's not a huge difference, but definitely a noticeable change. I checked the battery and it was at 12V. The alternator looked ok too - I can't remember the exact voltage but I think it was around 13.5V with the truck idling. Has anyone else noticed this or is it possible that I have some other type of electrical problem?

 

[sharp4runr]

How old is the battery? Also do you have a lot of electronics (Subs, Amps etc) that may be drawing a lot of power?

 

[DblA]

Not sure about the battery age. I'm at 89k and it's possible that it's the original. I don't have any amps, subs etc. so that's not a problem.

 

[marko3xl3]

I get the same thing happening here in the cold mornings. It's nothing to worry about. The fix? Beef up all your battery cables, especially ground ones and the problem should oh-so magically disappear. There should be threads about this already too.