Alternator wiring question.

[kaherc]

I have an 82 mercruiser 898. Recently spent way too much time and money upgrading parts and pieces, one of them being the alternator. Had a 3 wire (I guess) with an external voltage regulator and now have a new one wire with an internal regulator. Can anyone tell me how to wire this thing up? The old one had 4-5 wires going to it and now the new one has a nut to attach a wire to and a black and red wire sticking out of it and thats it. <br />Also I could really use some help figuring out how to wire the batteries up. Theres a selector swith already hooked up with the black going to the starter and a red to each of the numbered positions on the switch with the bitter ends laying on the deck. Theres a black wire from one negative to the other negative. Dont know what else to do. Is there anyone that has or knows how to get the wiring diagram for this stuff. I have the manual for the motor, but its not clear. To me anyway. Help me out please.<br />Korie USCG

 

[Silvertip]

Re: Alternator wiring question.

Lets start with the batteries. The switch allows you to use either or both batteries for starting and operating accessories. The NEG terminal on each battery must be connected together. The NEG battery cable from the engine should connect to the NEG post on either battery. The POS post on each battery should connect to one of the numbered posts on the switch as you indicated. The COM (common) terminal on the switch should have a large cable that runs to the starter solenoid on the engine. It appears that part of the system is correctly wired. As for the alternator, the bigger of the posts (the one with the nut) goes to the starter solenoid. The other two wires are the "sense" wire and probably the alternator "Idiot light" on the dash. I assume this is a GM alternator so any GM car shop manual from the 80's will have a diagram how this is wired. Your library probably has many of these manuals.