HUD won't stay fully illuminated

[Vetteforfun]

My HUD brightness goes from full to about half and it stays that way until I shut the car off and restart. But then then the display dims again within a minute or two. Any one have thoughts as to what this may be related to?;help

 

[navy2kcoupe]

My HUD brightness goes from full to about half and it stays that way until I shut the car off and restart. But then then the display dims again within a minute or two. Any one have thoughts as to what this may be related to?;help

The HUD is supposed to adjust (get brighter) as it gets brighter outside. Maybe the sensor for the ambient light is faulty. Just my 2 pesos.......
Andy

 

[Vetteforfun]

The HUD is supposed to adjust (get brighter) as it gets brighter outside. Maybe the sensor for the ambient light is faulty. Just my 2 pesos.......
Andy

I didn't realize that it should be automatic. I have been sliding the the display bar to max. I'll check out that possibility. Thanks

 

[Roc]

I don't know of any C5s with auto dimming on the HUD. Perhaps if twilight sentinal is on it may dim or brighten but I have always used the slide rheostat to adjust HUD brightness and it's independent of the dash cluster dimmer.

Often when electrical gremlins start showing up like sudden dimming, gauges suddenly changing, warning lights popping on and off, it's a sign that the battery is going bad. The charging system may still be working but the battery can't support the bus voltage under draw. This is most prevalent in cold of winter and mid-end of summer. It's a mistake to think that the alternator will keep a battery fully charged. I routinely put cars on a tender over night just to push the battery back up to full; makes them last a lot longer.

My .02 but I have had low use vehicles have batteries last up to 8 years+ just by taking some reasonable precautions with them.

 

[navy2kcoupe]

I don't know of any C5s with auto dimming on the HUD. Perhaps if twilight sentinal is on it may dim or brighten but I have always used the slide rheostat to adjust HUD brightness and it's independent of the dash cluster dimmer.

Often when electrical gremlins start showing up like sudden dimming, gauges suddenly changing, warning lights popping on and off, it's a sign that the battery is going bad. The charging system may still be working but the battery can't support the bus voltage under draw. This is most prevalent in cold of winter and mid-end of summer. It's a mistake to think that the alternator will keep a battery fully charged. I routinely put cars on a tender over night just to push the battery back up to full; makes them last a lot longer.

My .02 but I have had low use vehicles have batteries last up to 8 years+ just by taking some reasonable precautions with them.

Roc, from page 2-89 of my 2000 owners manual.....
Section 1. "Start your engine and slide the HUD dimmer control all the way up.
The brightness of the HUD image is determined by the ambient light conditions in the direction your vehicle is facing and where you have the HUD dimmer control set. If you are facing a dark object or a heavily shaded area, your HUD may anticipate you are entering a dark area and may begin to dim".
Andy

 

[Roc]

Roc, from page 2-89 of my 2000 owners manual.....
Section 1. "Start your engine and slide the HUD dimmer control all the way up.
The brightness of the HUD image is determined by the ambient light conditions in the direction your vehicle is facing and where you have the HUD dimmer control set. If you are facing a dark object or a heavily shaded area, your HUD may anticipate you are entering a dark area and may begin to dim".
Andy

I have read lots of things in owners manuals over the years...doesn't mean that the item actually works as written. I have yet to see a HUD that automatically functions that way. I routinely slide the dimmer down in dark areas and at night because the autodimming is either non-existent or minimal.

I get to drive A LOT of C5s and C6s and that's been pretty consistent for me. YMMV

 

[Vetteforfun]

Thanks guys for your input. It must have been the battery. It finially died last night. I'm pretty sure it's the original battery from 99. The car only has 32000 miles, not a daily driver. I'll get another battery and hopefully this will take care of the problem.