Short in harness????? By glutton4punishment (Read 659 times)

[glutton4punishment]

Hi, everybody. Before I joined, I did a lot of lurking, and you guys are the smartest around!

Anyway, I've got a 2001 SYM Joyride 150 (I believe it's Taiwanese).

It blows the main fuse when ign switch is turned on (before trying to start anything).

Using a VOM (one lead attached to the frame), I've found that the wires that lead to the license plate light and the left turn signal are grounding out. To my great dismay, when I unplug the harness next to the rear lights, and unplug the harness next to the steering head, that the shorts are not in the lights themselves. (I am also getting a short from a black and white wire that goes to unit the CDI unit. I wish I could give more info on this wire, but the only wiring diagram I have is out of focus, and I can't attach it)

i.e., the short is in the harness that goes along the frame to the steering head. When I test the harness, that is where the VOM beeps when .

I've looked inside the front part of the scooter, and there doesn't seem to be any movement of anything against the harness.

WHAT TO DO?? (I don't want to buy a new harness).

[Cruiser]

Welcome to the forum, g4p. The black/white wire you mentioned is usually connected to the ignition and kill switches. When the ignition is off, this wire will read as a short to ground. This will also happen when the kill switch is put into the no-run or kill engine position.

The short appears to be associated with the wire or wires that feed the left turn signal and license plate lights.

Here's a service manual for your scoot from our files:

www.chinesescooterreference.com/jr/Sym_Joyride_Service_Manual.pdf

The wiring diagram should help narrow down which wires to concentrate on. Good Luck!

[rob63]

Electrics are all black magic to me but here`s my two penneth.
At some point in your system an earth is crossing over to a positive wire when it`s not supposed to, either in a unit or by bare wires touching each other in the loom.
Bearing in mind that I`ve no idea if the wiring diagram in the service manual is identical to the wiring on your bike, but looking at the wiring diagram it seems that the battery positive feed goes via a thick red wire to the starter solenoid, then a thinner fused red wire (presumably spliced onto the thicker one), goes to the main fuse box assembly, through another fuse, then splits to two red wires. One goes to the regulator/rectifier, the other goes through a multiplug to another multiplug attached to the main speed/fuel/temp display on the dashboard.
It might help to try and isolate by disconnecting each of the components in turn (reg/rect, dashboard, starter solenoid) and switch on the ignition each time to see if the fuse still blows. This may help to isolate the problem to a certain unit or to a certain point in the loom.
As Cruiser mentioned, the black/white wire is the kill wire and will be showing an earth with the ignition and kill switch off. If the wire shows an earth with both ignition switch and kill switch in the run position then it might be wise to disconnect the kill switch to check if that is causing the fuse to blow.
Good luck

[Bashan]

How about the ignition switch? Maybe it's shorted out. Those switches are usually pretty complex. And yes, that diagram is unreadable. Rich