Had new trolling motor Altrex and new (2) Hummingbird grafts installed at same time.   The bolts on trolling motor head and jack plate have oxidization    Any help would be greatly appreciated as  to where to look for problem

 

 

Oxidation or corrosion?

Could be several things if the fasteners are not 316 SST.

Dissimilar metals create electrical current creating oxidation before serious corrosion occurs. Aluminum is dissimilar to Stainless steel it needs to be sealed using a sealant like 3M 5200. Your TM motor has a zinc anode to be sacrificial protecting the less noble metals like aluminum, check the zinc anode.

WD-40 was developed for this issue, clean the oxides off use it.

Tom

Are you fishing brackish water? Minnkota’s warranty is void if you use the motor in brackish water. 

It could be corrosion    And clear water

 

It also might be road salts causing filiform corrosion. Common in snow states & eventually shows up on most aluminum wheels. Usually looks like the image below when growing under a coated surface. The worm-like tendrils with some blistering are common identifiers. Will be a grayish brown, black or white growing under clear coat or on uncoated metal surface, usually steels, aluminum or magnesium.