1974 Aermacchi 350 not charging

ascot500

New Member
I recently resurrected this SS350 from perhaps decades of storage
All is well except the battery is not being recharged
I have a bar mounted volt meter to verify this
The original R/R was toast so I am using one of the pit bike units as shown below
The 'Macchi has two alternator coils - one for the headlight and one for everything else
The HL coil leads are black and green, and the other coil is black and brown
Per the original schematic, when the HL is on, the brown and green are spliced, essentially making both coils parallel and supplying the extra amps
At idle, there is about 9 volts AC coming from both coils but it increases to over 15 v with increased rpm

I have a three position switch that turns on the ignition in one position and ignition and and HL in the second position
This allows me to kick start it and then turn on the headlight after it's idling
I have a jumper between brown and green so that both coils are feeding the R/R

Did I do something wrong here? Did I ruin the R/R by sending it too many AC amps?
Should I use a separate R/R for the lighting coil?
 

Attachments

  • regulator-rectifier.jpg
    regulator-rectifier.jpg
    218.5 KB · Views: 239
  • pit bike reg.jpg
    pit bike reg.jpg
    17.4 KB · Views: 424
OK. Setup is not dissimilar to a Honda twin. I'm not sure that four pin R/R will work for you, but it might. I would have expected to see a five wire unit, but it's possible that the voltage sensing on your R/R is done internally and they were able to do away with that wire.

Here's what I would do:
Stator appears to have two brown wires and a green wire. Splice both brown wires together and run then to yellow on the R/R. Green goes to the other AC wire (blue? green?). Other two wires on the R/R look good; red to battery positive and green to ground.
 
The two brown wires are already spliced together from the factory
The black is the AC common, so voltage is between black and green, and black and brown

Here is how I currently have it wired:
 

Attachments

  • regulator-rectifier.jpg
    regulator-rectifier.jpg
    154.3 KB · Views: 282
I think I maybe misread the diagram (my eyes aren't cut out for small fonts anymore)...

So alternator is black, brown, and black?

I think your hookup is correct. Brown and green together to connect to yellow.
 
You said: "So alternator is black, brown, and black?"

I think you meant black, brown and green - which is correct
So if my connections are correct, then the R/R must be suspect

Thanks for the help
 
ascot500 said:
You said: "So alternator is black, brown, and black?"

I think you meant black, brown and green - which is correct

lol... yeah.

Time for another cup of coffee.
 
Back
Top Bottom