5 pin plug on quicksilver remote

[Sneed-0]

I am new to the boat game, so please forgive my ignorance. In the process of completely restoring an 89 alumacraft. It has a 115 merc on it and the original remote was toast. I found one on ebay fortunately. My question is, what is the purpose of the 5 pin plug on front of the remote? I've read its tach, and trim. Is this correct?

 

[haventaclue]

It's tach which is grey,Purple is 12v+ for guage lights,black is ground,tan is temperature gauge and brown/white is trim gauge

 

[Sneed-0]

thank you