Use a Digital Multi-Meter DMM and self powered OHMS setting (with no power connection to the lights), and measure each spade lug with respect to bike chassis. You can determine if one of the two spade leads is grounded to chassis; then check your service manual wiring diagram for running lights option and verify color code and plug wiring harness, relay wiring and polarity matchup. Since the fuse does not blow immediately, you are probably exceeding the current rating of your headlamp fuse, or have sneak leakage current due to improper/pinched wiring, and may have to run a separate circuit, fuse, switch/relay for your driving lights (which were probably just wired in parallel for speed, simplicity or laziness if a new installation). Glider has a wiring diagram in his Maintenance Lighting thread... :57:
You should check how much current your driving lights are drawing. Your fuse rating for your headlamps may be exceeded...expecially if you bumped up your standard headlight power 55/60W to brighter aftermarket one 65/70W as an example with the burden of the accessory lighting exceeding the standard 15A fuse. P (Watts) = I (Amps) x E (Volts) :coffee