Author Topic: Wiring from PO-how bad is it?  (Read 440 times)

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Offline Irish Aussie 550-4

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Wiring from PO-how bad is it?
« on: July 08, 2015, 05:09:01 AM »
So folks,  my 550 4s wiring is looking a bit of a sad show, even my beginner eyes can see it.
I'm tossing up the idea of getting some professional help in but I'm asking you guys first.
As I can see it I have at least 5 wires loose without a home and a number of newer red wires with mods on them.
I have;
-A thin black wire from bolt holding the fuse box, melted sheath, unconnected, looks like it was once connected to the batt + terminal. Obviously too small for the load.
-2 small red wires with clamped connectors, unconnected, from the fuse box to connector to tail light/rear indicators
-a larger gauge red wire out of that same connector block (top right of pic) looping into a 20amp single fuse casing and back to the connector block (this bypasses the fuse box I'm guessing so is the fuse for the tail lights replacing those two loose reds?)
-a red wire,  with black paint on it (under seat, unconnected) out of harness, also looks like it went back to batt, possibly - terminal.
-a single blue wire soldered to a black wire with a thin rubber sleeve over it,  goes from starter to ground on the bolt holding fuse box? (you can see the silver of the shoulder in the pic)
Fuses-2x20amp 1x15amp,2x10amp. These are well higher than the required stock fuses for the bike.
Close up shows the wires at the back of the fuse box fuse brackets, sitting in the connection holes, unsoldered


With these unconnected wires I was still getting power in the controls and lights and starter,  up until an hour ago where,  on my second attempt to start her, it went ok for a few go's (turning engine over but no firing) but suddenly there's no power or lights anywhere. Am changing out fuses tomorrow.
Any one any diagnosis on what these loose ones are meant to be doing? Are some of these bits and pieces unsafe?
Is a motorcycle electrician or a new harness recommended?
There's other known issues with headlight and horn switches along with some strange goings on when I turn on the keys (the headlight stays on, switches do nothing) so im lost as to where to start. Losing power in the controls today has forced me to get into the wiring at last. I've been avoiding it like it's my mother in law!
1975 CB550-4

Offline calj737

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Re: Wiring from PO-how bad is it?
« Reply #1 on: July 08, 2015, 05:23:56 AM »
The wiring on these bikes is pretty simple really. There are ample color coded diagrams that will aide you in re-establishing the correct circuitry and routing to restore stock behavior. Also, replacing the stock glass tube fuses with a modern blade type block is a good choice at this point.

Grab a soldering gun, some vintage connector kits and unwind the rats nest around the electric panel. Remove all PO alterations and clean each of the plastic connectors well, reinstall the stock wiring, and check with a meter as you go.

Proper gauge wire and proper fuse ratings are essential to a safe and reliable motorbike.

It should take you less than 4 hours to completely repair and upgrade that panel. I don't know what shops charge near you, but at nearly £100/hr, that's a hefty bill and they won't finish in 4 hours with your credit card as an air line to their deep-dive excursion. (If you get my drift).

'74 550 Build http://forums.sohc4.net/index.php?topic=126401.0
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"Of all tyrannies, a tyranny sincerely exercised for the good of it's victim may be the most oppressive. It may be better to live under robber barons than under omnipotent moral busybodies. The robber baron's cruelty may sometimes sleep, his cupidity may at some point be satiated, but those who torment us for our own good will torment us without end for they do so with the approval of their own conscience." - C.S. Lewis

Offline Irish Aussie 550-4

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Re: Wiring from PO-how bad is it?
« Reply #2 on: July 08, 2015, 06:41:55 AM »
Fair call, I had a guy in mind at 75 an hour but am loathe to use him as I got the bike to ride and learn, not take shortcuts and ride. That said I'm worried I'll do more harm than good.
4 hours? Really? I'm pretty fresh,  I have tried to piece stuff together but these anomalys are cropping up a bit and it makes me wonder why he's installed them in the first place. I'll take your advice on and upgrade the board and try to rewind the PO changes made.
Possibly a related question but is a slight crackling from the in the stator normal after trying to get her started for the first time in a while?
1975 CB550-4

Offline calj737

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Re: Wiring from PO-how bad is it?
« Reply #3 on: July 08, 2015, 06:54:30 AM »
Crackling? No, that's not a proper sign. Here's a troubleshooting diagram to use while you are repairing the harness to help assess the health of your charging system. If you don't already have one, purchase a decent multimeter. Spend a couple minutes getting acquainted with its proper use, and you'll be astonished at how truly simple this electrical stuff is!

http://www.electrosport.com/media/pdf/fault-finding-diagram.pdf
'74 550 Build http://forums.sohc4.net/index.php?topic=126401.0
'73 500 Build http://forums.sohc4.net/index.php?topic=132935.0

"Of all tyrannies, a tyranny sincerely exercised for the good of it's victim may be the most oppressive. It may be better to live under robber barons than under omnipotent moral busybodies. The robber baron's cruelty may sometimes sleep, his cupidity may at some point be satiated, but those who torment us for our own good will torment us without end for they do so with the approval of their own conscience." - C.S. Lewis

Offline przjohn

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Re: Wiring from PO-how bad is it?
« Reply #4 on: July 08, 2015, 02:33:48 PM »
Crackling? No, that's not a proper sign. Here's a troubleshooting diagram to use while you are repairing the harness to help assess the health of your charging system. If you don't already have one, purchase a decent multimeter. Spend a couple minutes getting acquainted with its proper use, and you'll be astonished at how truly simple this electrical stuff is!

http://www.electrosport.com/media/pdf/fault-finding-diagram.pdf

I agree whole heartedly. Get a decent meter and use the wiring diagrams available. It is like a puzzle,  once you start finding the faults and putting pieces together it is kind of like a good golf shot, oh-yeah got that one! Electrical is easy if you have patience, can read a wiring diagram, and use a meter, you just need a little practice.
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