After completing the rewire exactly as pictured (using 10amp fuses in place of 15amp), the mod works great. I can use my fog lamps with only the parking lights on.

However, after about 15 minutes or so, the lights turn off (the interior indicator goes from green back to red as well). Any reason for this? Is something heating up? The fuses are not broken and if I shut the car off and come back later it works for a while again.