I need some help! One of the bulbs in my cargo light cluster on the cab above the rear window keeps burning out with in a week of replacement. It turns all black inside and sometimes even seems to explode! I can't figure this one out.

Rooter

 

Rooter,

The problem is moisture. There is a leak some where and water is getting in and blowing the bulb.

Regards

Jean Marc Chartier

 

He lives in the desert, JMC Rooter, there is "something" wrong with the cargo lights on these trucks, my sockets are melting and turning black. I tried some superwhite bulbs, and they burned out in a week. Regular bulbs seem to last a little longer for me. I don't know why they do it either. I don't remember metal sockets being this much trouble, maybe they should go back.,,,,98

 

Rooter,

How often do you wash your truck?
For a bulb to burn the filament must burn up or break. One cause is moisture, another is too much current and a third is excess vibration or shock to the filament. A black bulb is a sign of moisture. If there was too much current both bulbs would burn as they are wired in parallel. If there was too much vibration or a shock so violent to break the filament , I would suspect that both bulbs and the Stop lamps would also break.

Regards

Jean Marc Chartier