I would like to answer your question one by one as below.

1. what’s bulb size of 2017 ford f150 fog light bulb replacement

I have checked our auto lighting system, 2017 ford f150 light bulb replacement shall be 9140 bulb.

Frankly speaking, Almost of 9140 bulb can be replaced by 9005 because they are same sockets.

2. halogen headlights ford explorer

In USA, halogen headlights for ford explorer only one type that’s 9005 bulbs.

When you replacement 2017 ford fog light bulb and halogen headlights ford explorer, please wear gloves in advance.

If you would like to get more information about 2017 ford fog light replacement and halogen headlights ford explorer, please contact my factory quickly.