Do I just apply it directly with nothing else sealing it? Can I just spray the outside of the controller or do I open it?
I would use it on your connections. I don't know how it would do with the heat. I had one of those cheap garage door openers I took it apart sprayed its down well let it dry and then ran water over it and it worked fine while the water was running over it and it has been on my bike for 2 years and countless rain rides.
Common mistake.
I've found that silicone doesn't stay stuck well to plastics and rubber and can actually trap water underneath over time. Though 3m mentions vinyl and rubber as recommended surfaces, but not plastics.I've had good luck with this Loctite silicone sealant:
Loctite Silicone Waterproof Multipurpose Adhesive Sealant 2.7 oz. Clear Tube (each) 908570 - The Home Depot
Loctite Clear Silicone is a multipurpose adhesive and sealant which creates a permanent waterproof, protective seal that is ideal for metal, glass, rubber, tile and porcelain. Designed for indoor and outdoor use, Loctite Clear Silicone Waterproof Sealant can repair everything from electrical...www.homedepot.com
I use it to seal cable openings, housings and around the outside of connector joints. it dries to a rubbery consistency in about an hour and remains flexible. It can easily be removed to separate parts when necessary.
