I take off to work this morning & find out my low beams aren't working &^%^& I had no time to tinker with it so I drove to work using just the driving lights. Not as bright as low beams but, got me to work lol

The high beams work fine... and because the driving lights DID work that tells me something, right? Because they normally only work with the low beams only, so that circuit is ok. Because both lowbeams don't work (they did last night) I'm assuming BOTH low beam bulbs can't be shot. The switch does work to allow me to use highbeams & running lights so, I guess that's OK too. What else to check?

 

you can always pull the
connector and measure
with a voltmeter

 

My F150 did that, and there was actually a seperate hi and low beam fuse, it was wierd, you may have the same thing and that may be the problem.

Ryan

 

Thanks guys. I looked thru the shop manual and, according to it I have 2 low beam fuses, 1 for the left 1 for the right,, GEEZ is that overkill or just a safety feature to prevent both lights from piffing out @ the same time??

Anyway I checked ALL the fused & they were all fine. All this time I assumed the problem probably wasn't the bulbs, because what are the odds both lowbeams would pop at the same time?? Well, apparently Murphys law strikes again because thats exactly what was wrong. BOTH lowbeam bulbs were blown!!?!

I replaced both bulbs and now all is OK. But I'm still nervous if there's still a root problem that caused both bulbs to pop like that(?) It's a good thing the driving lights can be used for backup if/when these bulbs blow [:@]

Oh, and the bad bulbs were Sylvania Silverstars I put in about 2 years ago, so they weren't very old.

 

Bulbs typically blow when you turn them on. The current spike kills the filament that is already weak.
It is neraly imposible for both of them to go at the same time but it can ( as you have proven) happen......

Check your alternator output and grounds.
I have seen the oscillations caused by a loose ground blow bulbs