Last week my husband's truck mysteriously blew it's headlights, so I had them replaced. This morning he goes to drive to work and the headlights are blown again! Does anyone have any ideas as to what's causing this? It's a '98 Dodge RAM 1500 5.9 V8.

 

Has anyone checked the headlight switch in the dash? Common weak point.

 

+1 on the switch. sounds like your gettin a voltage spike and its poppin them. is the fuse still good and rated for the right amount? and check the voltage coming into the headlight connector and see if its steady while your turnin the switch on and the high beams and what not.

 

There really isn't a way for the lights to get MORE than alternator output voltage, DC current with common ground cannot double voltage, only source of higher voltage is the ignition coil circuit from the ECM other than the high tension secondary ignition system...so you need to check SYSTEM voltage. There is however the incorrect headlights, for instance dual element lights with both elements stuck ON will burn them out pretty dang quick, so in that way it could be the high beam circuit and/or headlight switch circuit.