CB750F1 Wiring loom problems and ignition switch

[martin_uk]

Just finishing off my last F1 and had bought a new repro wiring loom from DS and a repro ignition switch.

I had to use one of the US spec position wires (Orange/White) to feed switched live to Black in headlamp bowls.

Tail light and pilot would not work although tail did come on in park position on key.

Wiring diagram shows 2 brown wires join by ignition switch but mine did not have a connection in loom, so put in a jumper wire.

Still a problem with tail coming on with handle bar switch.

Fitted an old ignition switch and works fine inc pilot light.

I assume some of the repro ignition switches do not have internal connection required so something to look out for.

[martin_uk]

Another electrical problem as not charging

I had fitted a solid state regulator/rectifier so suspected that,

One of the quick checks is to see if the field winding screws on outside of alternator case are magnetised with ignition on, meaning power is going to field winding.

If the battery is at higher voltage or too low may not work as regulator not calling for charge.

You can use a metal screw or bolt on the screw heads.

In my case not magnetised.

Swapped  new solid state reg/rect for a spare original, but same problem.

Suspected field winding, but resistance within spec between white and green tested at sub loom.

Mmmm maybe the old regulator is faulty, so tried another spare, but same problem.

Checked continuity on sub loom and earth and switched power to regulator.

I had disconnected sub loom that connects main loom to alternator and this was also new.

Checking the orientation of wires and noticed that the White wires did not line up !!

I have the old loom and the new loom from DS had white wire opposite to original.

Removed the White wire after depressing tang that holds in block and refitted in correct position and connected everything.

Now the field windings are magnetised 

Hope this helps other with problems with repro parts.