merc 115 question

[fordmugg]

i have a 1973 mercury 115hp outboard ....my question is are these motors suppost to rechage the battery because mine doesnt ....so when i go out i have to make sure the battery is fully charged ....i dont know if somthing has been taken off of it or thats the way they are .....thanks

 

[Tech]

Re: merc 115 question

The short answer is yes, it should charge the battery. Check your rectifier (small block with 3 wires, 2 yellow and one red) by doing a simple voltage test. at idle you should see somewhere around 12vdc and the voltage should increase with RPM. If not, either the rectifier or stator could be suspect. Check the service manual for proper test procedures for both.

 

[fordmugg]

Re: merc 115 question

ok thanks i'll need to check that out

 

[cell]

Re: merc 115 question

Facing the prop look on the right side of the engine....with the cowl off.you should see two wires coming down from the top.these wires should be screwed on a small block.Check that the connection is good there too.I had a loose connection fixed it and now Im charging.
If you do solve the problem,and it starts to charge keep in mind the charge will be about 16 volts.

 

[fordmugg]

Re: merc 115 question

thanks im going out there in a bit to check it out ....i hope i can fix it because it never worked and i always had to charge the battery before i went out

 

[Jim662]

Re: merc 115 question

Look to make sure that the two wires coming from the stator on the right side (described in the last post) are not corroded through. I bought a parts motor and they were rotted away at the stator. Be gentle in checking though, you don't want to create a problem where you didn't have one. The insulation is old, brittle and bad.

 

[fordmugg]

Re: merc 115 question

well here is the thing ...i keep the boat at my moms and im going up there in a little bit .....so i was wondering if i get confused and cant figure it out the charging system is if one of you minded if i called you to kind of walk me through it ....you can pm me your number ..

thanks

 

[cell]

Re: merc 115 question

If you cant call any one just print some diagrams out and take em with you.hold on ill post a link were you can find some.


Sorry man I cant find the diagram.Im sure theres on on here if you search for

stator diagram

 

[cell]

Re: merc 115 question

http://www.maxrules.com/MERCwireindex.html


Just look for your hp engine,and there you go.Be sure to check out the other stuff on that site.

 

[fordmugg]

Re: merc 115 question

ok i checked the volts at the rectifier .......it bounced around but seemed like it was around 17v .....all the connections were good so can it be in the big plugs ....maybe the wire came loose in there .....its hard because they dont come apart .......looking at the diagram the power from the rectifier ties in with the main wire inside the plug....so can i splice it to the power wire going to the starter seliniod and see if that works

 

[cell]

Re: merc 115 question

Make sure the wires are good,and be careful not to tug on em to hard!Usually...but not always, an electrical part will just not work when it fails.

Id check to see if you have 16 volts at the battery first.You might just have a bunk batt.