You have a short circuit. make sure a bare wire is not touching metal Found the answer: I had a bad daytime running light module.
The correct grammar would be "Why would both of your headlights blow out at the same time".
your headlights will burn out faster and could possibly blow a fuse, but you would go through headlights and a drastically increased rate if you use headlights when they are unneeded.
There is a voltage regulator located on the internals of you alternator replace the altenator. Voltage regulator keeps voltage constant and stops spikes in power output, this is what is causing your headlights to blow.
blow fuse, bad motor, bad switch or wiring
sounds like a short circuit in trailer plug or wires to it?
It is possible that both of the fuses are bad for the low beam headlights and the cruise control. A loose ground wire could cause the fuses to blow.
There is a electrical short somewhere...
Replace the high speed relay.
Your headlights may not dim because you don't have dimmer lights. Dimmer lights can blow and leave you with just the high beams.
Leak in heater core. Replace core.
The fuse will blow when the current draw in the circuit that the fuse is protecting is more than the rating of the fuse. It usually indicates a faulty componet in the circuit or grounded wiring.
Check the Horn wiring and if this is good then replace the horn.