Headlights dim/electrical draw?

[Brandon2489]

Vehicle info. 2011 Tahoe LS 4x4. Bought with 80k and now has 136k.

On to the concern. For the 4 years I have had the tahoe I have always noticed the headlights would randomly dim while driving at night. Tonight I realized they dim when the electric fans kick on. I also noticed the voltage gauge was reading around 12 volts and the headlights seemed dim. After about 5 miles or so the voltage was back to 14 volts and headlights seemed brighter. This may be my eyes playing tricks on me as well. I should note I usually don't look at the volt gauge often. So I can't say if it normally does this or not. Has anyone else noticed this with the headlights? I will be honest and say I am pushing my luck on my battery. I have never replaced the battery and I do not know the last time it was done. The date is no longer legible on the sticker. Although I do not think it is a battery issue at the moment.

 

[RedInCo]

12 volts is low.

On my 2010, when you turn on tow/haul mode, the voltage holds at a higher level than normal. That is so it does a better job of providing power to a travel trailer. You could try tow/haul mode and see if that gives you brighter lights/higher voltage.

 

[Doubeleive]

my fix would be:
new battery, ground headlight harness to frame on each side.
oh ya, that is my fix, lol that and some nice hid's, they don't dim.

 

[Brandon2489]

my fix would be:
new battery, ground headlight harness to frame on each side.
oh ya, that is my fix, lol that and some nice hid's, they don't dim.

Thanks for the advice. Question for you? Are you using projectors with you hid's or just the hid's in stock reflector?

 

[Joseph Garcia]

These trucks have internals that reduce the draw on the alternator, when not needed, so you will see some occasional fluctuations on voltage on the gauge, bringing it below 14 volts. That is normal.

I do not believe that your light dimming issue is directly associated with the changes in voltage that you are seeing on the gauge. As suggested above, replace your battery and clean up any electrical connections associated with the battery/alternator/ground circuit. Once your battery is replaced and all primary wire and ground connections are clean and tight, if the dimming issue still exists, then we can further troubleshoot with you.

 

[Doubeleive]

Thanks for the advice. Question for you? Are you using projectors with you hid's or just the hid's in stock reflector?

hid's in the stock housing, some guys do the whole bake them in the oven and install projector thing but not my cup of tea so too say.

 

[Doubeleive]

if you go hid do it right with a couple relays and wired to the battery and it will work great, the stock wiring isn't really hid friendly

 

[CaptainAmerica1]

The way the light sensor works will wear hids out with all the flickering at vehicle startup, I wired in a 10 second timer to my light sensor so they come on after the truck is already started.

 

[petethepug]

You’re due for new battery cables. It’s can be considered a maintenance item after 100k mi. The dimming effect is the BCM (ECM) tied into the entire system that works as a regulator.

The new cables will help to eliminate the draw down you’re experiencing. A HID kit is the way to go in the future for adequate lighting. As others have stated make sure you relay the HID to the stock switch. That flickering on start up can wreak havoc on other systems and is a side effect of inadequate voltage or ground on start up. The relay will help isolate the HID igniter from the system.

 

[avalonandl]

I installed Sealight LED bulbs, they work well. Not as bright as HID but doesnt draw as much juice.