FZRSupport: the FZROnline Archive

How comparable are the FZR400 and FZR600 wiring harnesses? I have a perfect FZR600 harness and a new FZR400 with questionable wiring.

They're pretty close. Yamaha coloured the connectors so most of it is easy to change over. The differences came when the 400 got the exup.
Before you remove the old one lay the 600 loom over the bike and you'll see any differences. Then unclip and reattach the connections one by one.

The relays are quite different, with the 600 bundling several functions that use discrete components on the 400. Also, the plugs are different on the TCI; the tach has a dedicated wire on the later 600s, while the 400 and early 600 taps into the 2-3 coil control wire.

Sit down with the harnesses and the wiring diagrams, and start following wires. Take lots of notes.

+1 to Don's advice. Having both bikes myself, I can assure you that the harnesses are not nearly close enough to be a quick swap. His description of the primary differences is spot-on so you'll just need to take the time to sort out which modifications you'll need to make.

What does this connector go to? I can't identify what is missing.

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I'm assuming that's the 400 harness since it's on the bike, but - looking at the wiring diagram - I don't see anything with that shape or wire color combo on either the 400 1WG or the 600 3HE.

Rear brake light switch? (Its yellow/brown + black plug on the 250)

Maybe I was looking at the pic wrong; it looked like a 4-way with only 2 positions in use. If it's a 2-way plug, then yeah - I agree with Grey Import.

That IS the rear brake light switch connection and is identical on all 1WG configurations and at least the 600 3HE.

Yes, that is the 400 wiring harness. Now I have to search for the opposite end to match up to it. At least I know where to start looking. The bike has spent time as a race bike so there may not be a rear brake light switch. The taillight is currently working though.

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Last unidentified connector. In the tail piece. Three wires. Red with white stripe, gray, black. All connections to the taillight and turn signals seem to be accounted for.

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That goes to the stand-alone EXUP controller. Just about every other bike that had an EXUP integrated the controller into the TCI box, but the 1WG 400s had an external box. If that plug is flapping in the breeze, I'm going to assume you have a) no EXUP servo, and b) an aftermarket pipe on the bike.

Yes to both a and b. It has a Vance & Hines full system so it all makes sense. Thanks.

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