How do you tell if the main beam bulb has blow.

[2007 Denali XL]

Hi,

I've lost my main beam, both headlamps. All other lights work fine, including high beam. Check fuses/relays noting doing there so pulled the bulbs. My question is how do you know if this is blown, both main and high beam are delivered from this guy and high beam works great.

Help please, before I waste money on new bulbs.

 

[avalonandl]

The low beams are used for the daytime running lights so it makes sense that you lose those first. New bulbs are only $30 a pair

 

[Doubeleive]

connect 12volts to the bulb, should have 3 legs, 1 for high, 1 for low, 1 ground

 

[kbuskill]

Hi,

I've lost my main beam, both headlamps. All other lights work fine, including high beam. Check fuses/relays noting doing there so pulled the bulbs. My question is how do you know if this is blown, both main and high beam are delivered from this guy and high beam works great.

Help please, before I waste money on new bulbs.

View attachment 252954

It appears blown to me. There is nothing connecting the filament to the positive lead inside the bulb...


It should look like this....

 

[2007 Denali XL]

connect 12volts to the bulb, should have 3 legs, 1 for high, 1 for low, 1 ground

You were right Bro, did the test as you described and hey **, both low beam filaments blown.

2 nice new ones installed.

 

[2007 Denali XL]

It appears blown to me. There is nothing connecting the filament to the positive lead inside the bulb...
View attachment 253040

It should look like this....
View attachment 253041

right on, well spotted

 

[wjburken]

Love the contrast of people’s attitudes on this forum. Here, we have @2007 Denali XL wanting to fully test light bulbs before throwing money at it with new bulbs. On the other hand, we have folks that have come on here and swapped out $100’s of their hard earned money without any hint of diagnostics.

 

[2007 Denali XL]

Love the contrast of people’s attitudes on this forum. Here, we have @2007 Denali XL wanting to fully test light bulbs before throwing money at it with new bulbs. On the other hand, we have folks that have come on here and swapped out $100’s of their hard earned money without any hint of diagnostics.

man, I have wasted so much hard earned money by not taking the time to work out the root cause, I learned the hard way. Measure twice cut once!!!!

 

[Joseph Garcia]

Love the contrast of people’s attitudes on this forum. Here, we have @2007 Denali XL wanting to fully test light bulbs before throwing money at it with new bulbs. On the other hand, we have folks that have come on here and swapped out $100’s of their hard earned money without any hint of diagnostics.

We all learn in different ways.

I have 2 grown sons, and their learning experiences were completely opposite. One son would listen and take away the recommendations, and use these experiences of others to chart his own course in detail, before moving forward. The other son would hear, but not listen, and have to learn on his own through trial and error - like finding out that a stove element turned on was HOT by touching it; like finding out how shocking an invisible fence dog collar electrode was by touching it when close proximity to the trigger wire.

You can guess which one took after me in learning experiences.