No tach,no charging

[Ifishmuskie2]

1994 mariner 115hp on StarCraft.
Boat worked fine then next trip no tachometer and no battery charging.
I pulled the rectifier and it has a burn spot in the clear underside.
So I put a new rectifier in and water tested.
Still no tach or charging.
What do I do now?

 

[Mc Tool]

I would say at a guess that you have also got a fried alternator , For the reg to have a hole burnt in it something has got very hot , usually a short in the reg and that will cause high current flow in the alt windings and fry them too . you need to disconnect the 3 wires from the alt and measure the resistance between them, and to earth . Winding resistance should be between 0.2 - 1 ohms ....not a dead short or open circuit ( with such low resistances you need to touch your meter probes together to see what the resistance reading is and then factor that in when you test the windings ) . Resistance between windings and earth should be totally open circuit.

 

[Ifishmuskie2]

I’m going to check it right now.
I have people wanting to go fishing.

 

[Ifishmuskie2]

I can’t see any access to the stator wires.

 

[Ifishmuskie2]

I disconnected the red, red and white, blue, blue and white.wires. They are open circuit to ground.

 

[Mc Tool]

there should be 3 yellow wires .... these are the 3 phases from the alt and should go to the reg / rect you replaced . resistance should be between 0.1 ohm and 1 ohm between any two yellows ( check them all ) and open circuit between any yellow to ground .

 

[Ifishmuskie2]

Ok thanks. I see the three yellow wires.
I had to stop for dinner. I’ll be back at it first thing in the morning.

 

[Dukedog]

bad stator.......... maybe regulator also.. it sounds like ya don't have tha right stuff ta check all three pieces so.......... replace all three pieces, regulator, rectifier, stator and be done with it.............

 

[Chris1956]

According to Crowley, lower serial numbers of that motor have a unregulated charging system consisting of a stator and rectifier. Higher serial numbers have a stator and voltage rectifier.

Stators are usually tough enough to easily survive rectifier burning. Usually there are 2 yellow wires of the stator that connect to the two AC terminals on the rectifier. Most OEM rectifiers are grounded to the block. You might check your connections and if correct, test the new rectifier.

The tach signal wire is connected to either of the yellow wires on the rectifier.