Wiring schematics & diagrams

Disclaimer & warning:

Be careful when using these diagrams. The harness changed bit by bit over the years. You can use the schematic to find the wire you're looking for, but don't assume that it's correct. Test any wire for function before splicing into/diverting/eliminating it. For instance, the wiring diagram in the 2002 Service Manual Supplement isn't even 100% correct for the '02 bike, and the '04 is different yet.

Tip: Yellow and black wire is ground throughout the bike.

General schematics

EX250 Wiring Schematic (full color - large & detailed)

Old Wiring Schematic (B&W)

Start & Ignition Schematic (full color)

Start & Ignition Troubleshoot Schematic (full color)

Starter circuit schematic

Ignition circuit schematic

Headlight circuit schematic

Assorted schematics by Anna's Dad

Anna's Dad is pretty good with CAD software, and he has drawn up a number of useful diagrams and schematics for the 250F. The full-color ones listed above are his.

He has set up a site where he can post his drawings and any updates he makes to them. Follow the link below to the table of contents:

Anna's Dad EX250F schematics

As of September 2010, the following drawings were listed:

• Aftermarket Horn Schematic
• Cooling Fan Circuit Discussion
• Hazard Flashers Addition - Rev 1
• Handlebar Heaters Schematic - Rev 1
• Start & Ignition Relay Discussion I
• Start & Ignition Relay Discussion II
• Start & Ignition Relay Discussion III
• Stebel Horn Schematic - Rev 3
• Turn Signal Circuit Discussion
• Turn Signal Schematic - Rev 3
• Wiring Schematic - Rev 2