08 Double cab 4.0 TRD offroad 6spd. Headlight bulbs burnout every 2-3 months, and usually just the low beam. It alternates between driver side and passenger side, for the past two years I have gone through 4-5 bulbs a year. I always wear new latex gloves when I replace them, I have cleaned the connectors, I replaced both housings suspecting the cracks in the originals were letting moisture in. I just replaced the battery after my old one failed, cleaned the terminals and actually had to undo some wiring ˟˟˟˟ery which was basically a homemade extension wrapped in electrical tape on the positive lead to reach the terminal of the wrong battery that was installed. I did a running voltage test on new battery and it was 13.76V, what else can I check for? I see no loose connections, no frayed or exposed wiring. I at one point wanted to upgrade to LED bulbs but not if ˟˟˟˟ keeps burning out.

 

What kind of bulbs are you putting in?

 

The Silvania Xtravision 9003 type bulbs.