Plastic Connector to Blocking Diode Melting with Heat. Help! By carefulrider (Read 2,405 times)

[carefulrider]

Hello People:
The temp has not risen above freezing & I have chosen not to work on the scoot because I would be coming in so often to warm up.
I might not have been able to describe clearly what the symptom is. Picture in your mind's eye, the diode connected to the wiring harness by a 2-blade female plastic connector. Now pull off/withdraw this connector, revealing 2 blades protruding from the diode itself. These 2 blades are not parallel to each other. They are at 90° to each other. Now divert your attention to the white plastic connector that you just pulled off the diode blades. This connector has 2 wires leading into it from the wiring harness. If you take a VOM/multimeter & insert 1 probe of the meter into 1 female blade sheath of the connector (not the diode), & touch the other probe of the meter to a bare metal frame member of the scoot, you get a 12V or thereabouts reading on the volt meter.
Now if you insert the 1st probe of the meter into the 2nd female blade sheath of the connector & touch the other probe of the meter to the bare metal frame member of the scoot, you again get a similar 12V or thereabouts reading on the volt meter.
Please note that I have not done any checking of the diode itself; only the connector. Therefore, there is current flowing from both those wires leading into that plastic connector from the wiring harness.
I presume from what you have said, that there is a short in those wires. Do I then, have to cut open the harness & follow the wires along the harness to attempt to locate the short? If you say yes, I shall get ready to do this the next day it gets above freezing.
It's going to be March in a couple of days, & I think it's reasonable enough to expect some days next month when it will be above freezing. My patience has worn thin with the temperatures in the north-east this winter.
Thanks for your help thus far.

[JR]

Was both readings on the connector with the key switch off or on? If you have the key off and get twelve volts on both wires then you have the wire from the battery that goes through the 20 amp fuse shorted together with the red wire from the R/R.

If the key is on and you get voltage on both sides then the R/R is shorted out thus passing voltage from the black wire to the red wire on the R/R. You can test that theory by unplugging the R/R, turn the key on and see if you have voltage if your test was with the key on the first time.

[carefulrider]

Finally, a day above freezing:

The red wire has current with the ignition switch on & off.
The yellow wire has current only with the ignition switch on.


The plastic connector was so melted that I had to brake it off in order to access the wire clips. I didn't pay attention & now I don't know to which blade of the diode to connect the red & yellow wires.


That's where I am in the process. More days above freezing predicted this week, so I should be able to apply your advice & suggestions to the scoot daily. Thanks again.

[ellpee]

Re-reading this entire thread it sounds to me as if the plastic connector that plugs into the diode might be the cause of a short -- wires touched, allowing 12v to leak across from the wire that SHOULD have 12 to the one that SHOULDN'T, and oh by the way generating heat that caused the connector meltdown. Certainly a simpler possibility than the innards of the R/R, although that would be next in line in my mind.