So, I'm chasing a DRL/Foglight issue on a 99 Blazer (along with a few other things as well) and bought a switchdoctor MFS off Amazon for $25. Lifetime warranty made it a no-brainer I though. Here's the issue, there's a directional on the factory plug and no relief on the Switchdoctor. Any reason I shouldn't shave the nub off the factory plug?

Original factory switch

Switchdoctor switch w/o cutout next to the 3 pin side of driving light switch.

 

For the time being, I decided to shave the mechanical interference tab off and use the switch as-is. I DID get a call back from Switchdoctor shortly after posting this and talked to one of their techs who was unaware of the different styles of male plugs. They're going to look into it further to see if maybe there was/is an issue with the fog light switch provider and see what they can do going forward. It seems like they just started carrying this particular switch and the tech (Chris) was really helpful trying to figure out what was going on. I was having some trouble describing the difference and sent him here for the pics which literally show the difference better than my 'there's a nub that sticks out on the factory plug and fits into a slot' ever could. He'll either call me back later with more information but I also encouraged him to post anything he finds here as well. The switch itself worked fine and is identical in shape and size to the factory unit and it was nice to feel some positive detents on the 3 headlight settings again along with working lights behind them. Took less than a minute for me to shave off the mechanical tab and with the locking latch, there really isn't any need for a 'one way' tab to prevent reversing the plug. I don't think I'll have any concerns about buying other switches from them as others fail and supplies dry up at the picknpulls.

 

Useful post. Be sure to give a review for how it performs after a while.