Dim lights on AC controller?

[swagfu]

So the other day I get in the truck and it's raining like crazy. So I turn the wipers on, get the ac going. I turned the headlights on, as i usually just keep it on automatic. I looked down after a minute of driving and noticed the lights in the controller looked either very dim, or completely out. AC still worked perfect...well, what I consider perfect. Anyway, I took my brother and his family to that airport and on the way home it was lit like it should be. Then the rain came and I turned on the lights and wipers again. Dim light again. Then when I got home and turned the lights and wipers off, they were bright again. So today I had a loose connection in my door speaker. When I was done fixing it I took it out for a ride and it started to rain. Not too much, but enough to use the lights and wipers. I noticed the dim light again. Then I started to think it was connected somehow. So it seems that if I turn on the headlights the ac controller lights go dim.

Is this normal operation? I have never noticed it before until lately. But I do keep it set at automatic lights 98% of the time.

 

[docraymund]

You may have a low alternator output voltage and an old battery.

 

[swagfu]

You may have a low alternator output voltage and an old battery.

I actually figured it out. My brother borrowed my truck last week and had the automatic lights off and the dash dimmer set as low as possible. Thankfully it wasn't something worse.

 

[stamp11127]

Glad you didn't throw an alternator and battery at it.......

 

[swagfu]

nah..i could have lived with them dim. but if the ac quit working, that would be a different story. gotta have ac in florida.

 

[stamp11127]

I hear you on that. I lived in S.Fla for 15 years - I know all about sweating during the summer.