SOHC.co.uk Forums > CB500/550

Electrical help needed

(1/3) > >>

stidds:
Oh God I hear you groan.

I have a 1978 CB550K which I am rebuilding.  I have finally gotten to the dreaded wiring and I am having a real problem.

I have put a new battery on, and wired everything up as per the Haynes manual, however I have no life.

I have a new battery, and I have used a multimeter to trace the current.  The red cable at the ignition switch is live and when I put the key in the P position the brown wires have current and will light up the rear light.  Problem is that when I put the key in the On position I lose all power (even to the red cable).

I have looked at the ignition itself and it looks fine, I have even quickly directly wired the red cable to the black cable at the ignition switch and again I lose all power immediately.

Can anyone give me a direction to go?

Thanks



Sean

K2-K6:
Try metering the black cable (if that's the power route into the loom) disconnect the battery and see if the black runs to earth with a continuity check to see if it's plugged wrongly somewhere. If not running to earth then try to find where it is going to make sure it's connected to something sensible.

Check main fuses are ok and meter through to the entry and exit wires of the fuse box.

Do you get any lights on with the ignition or nothing at all?

See what you get and post again for others to see if you get nowhere.

stidds:
Will do many thanks for your reply.

Just a quick question though, after looking at the loom a bit more some of the dodgy wiring is very thin wire, it looks like 5amp cabling (I have some that I used for comparison).  Would this cause the problem?

mickwinf:
i also have a k3 which was off the road for many years and when i fitted the new battery nothing much happened.i found that the fuse connections were not good they must be absolutely spotless, also dont forget the earth wire that fastens on the coil bracket, make sure it has clean metal to earth to.Another issue i had was one of the block connecters behind the fuse box was dirty and if not yet fitted it interupts the earth.Hope you get it sorted, electrics can be a nightmare! Actually i may have a spare loom in my shed,think it maybe a f1 though.Cheers, Mick

stidds:
Thanks for your reply Mick, that is excellent advice I will start checking the connections.

I think the 1st job is to take the loom off of the bike, remove the tape holding it together and see what I have and where it goes.  That way I can do some continuity testing of the cables.

I will get a supply of good quality wire and replace any bad parts.

Navigation

[0] Message Index

[#] Next page