For a challenge, I'm trying to repair a bad tach amp for a friend.

I picked away at the white silicone potting compound and found a badly burned out compoent that I cannot identify. Is there shematic of the tach amp somewhere? How about a wiring diagram of it in the car? I was not able to find a new one on Fastlane. Is it called something else? How much is a new one?

Here are a few poor quality pics I took while taking the tach amp apart:

Attached Thumbnails

       

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