Charging circuit diagram 1985 yamaha riva 180?

Im looking for a wiring diagram for a 1985 yamaha riva scooter that I am trying to fix for a friend. It does not charge the battery and i am not sure what part is needed to fix it.

You don't really need a diagram for a charging system. Charging systems have only three parts; Battery, Charge coil and regulator rectifier.

Now to the problem.

Step 1: put your multimeter on the battery set to VDC and check for state of charge. Should be between 12-13.5 VDC. If this is not the case charge the battery. A poorly charged battery may not take a charge from the motorcycle.

Step 2: With multimeter on battery turn the key on, brights on and hold the brake. If the charge drops like a rock (say .2 or so volts per second) he needs a new battery. A bad battery will not take a charge from the motorcycle.

Step 3: The stator should have 5 wires coming out of it, 3 yellow, 1 red and 1 black, black with yellow tracer or green (in the case that the system is full wave it may only have 2 yellow leads, and half wave 1 yellow, if half wave do all tests from lead to ground). Take the multimeter set to Ohms setting and connect it to your stator yellow leads. Check between all three leads the resistance should be less than 10 ohms. More than that it needs a new stator and reg/rec.

Step 4: Now check each yellow lead to the black, black yellow or green. All should have infinite resistance. If a wire is shorted replace stator and reg/rec.

Step 5: Check the yellow wires from the connector to the regulator/rectifier for a short to ground by touching one multimeter lead to each yellow lead and one to a chassis ground. If a lead is shorted will need to replace reg/rec. But proceed to step 6.

Step 6: Disconnect all five stator wires and start the bike. Set your multimeter to VAC and check voltage lead to lead on all three leads. Should be above 90 VAC output on all three connections. If less than that replace the stator and reg/rec.

If i have to replace a stator i always replace the reg/rec. More times than not when a bike comes to me with charging system issues it is the battery that needs to be replaced.

oldbikebarn.com or bikebandit.com

try here..

http://www.dansmc.com/shopmanual2.htm