Author Topic: 1978 CB550 Electricals  (Read 2315 times)

Offline cb550k-aaron

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1978 CB550 Electricals
« on: October 03, 2018, 11:20:42 AM »
Guys,

Having problems with my electrics, basically the new solid state Reg Rec i fitted, on the Black wire coming back into it is showing 1v Less than the Battery, therefore its telling the rectifier that the battery needs charging more when it really maybe doesn't.

Ill list what I have changed,
1) New Loom
2) New Fuse Box
3) New Coils
4) Dynatek Ignition in place of Points
5) New Hand Controls both sides
6) New lithium Battery

I've been through everything, earths, everything being wired properly, the stator everything!
I came to the Conclusion last night, that it's the Dynatek drawing the extra power because if I unplug it the 1v appears on the Black wire again.

I basically have to Run a new Black or Splice into the System before the White & Black that goes to the Coils that the Dynatek Connects to, has anyone got any idea where i could do this?

Rear light or horn maybe? The White and Black goes the the RH Switch which is Connected to Black as well.

I just don't want to Ruin a new Battery or anything else, so any suggestions at all would be appreciated!

Offline Bryanj

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Re: 1978 CB550 Electricals
« Reply #1 on: October 03, 2018, 03:52:47 PM »
The black is a switched power and nearest place,electrically, to battery is at the ignition switch

Offline cb550k-aaron

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Re: 1978 CB550 Electricals
« Reply #2 on: October 08, 2018, 04:38:04 PM »
The black is a switched power and nearest place,electrically, to battery is at the ignition switch

Will give it a go, thanks!

Offline cb550k-aaron

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Re: 1978 CB550 Electricals
« Reply #3 on: October 08, 2018, 08:18:17 PM »
Still having issues. The Black wire that goes into the Reg Rec is reading roughly 1v under what the battery says. Is this correct or should it not be basically the same as the battery voltage? I'm scared of over charging basically

Offline Bryanj

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Re: 1978 CB550 Electricals
« Reply #4 on: October 08, 2018, 08:36:32 PM »
1v is a bit much of a loss through the wiring suggesting a bad connection somewhere. With the pos probe on the battery check voltage on the bat, earth lead at engine, engine cases to see if earth connection is good ( should be same voltage at all points) Then assuming ground checks out ok with neg on battery work from bat + to solenoid, fuse(s) both ends, ignition switch input, ignition switch output etc to see where voltage is being lost

Offline cb550k-aaron

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Re: 1978 CB550 Electricals
« Reply #5 on: October 08, 2018, 10:07:58 PM »
So, with the Ignition on and bike not started.

All earth's seem perfect, All the same readings there.

Then Mulitimeter on battery Negative, Solenoid perfect, fuses perfect both ends, all red wires in and around battery all good.

Then,
Battery: 12.7
Key switch Red in : 12.0
Black Out: 11.8

If I unplug the Keyswitch, Battery is 12.7 and Red in Plug at Keyswitch is 12.6

Offline Bryanj

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Re: 1978 CB550 Electricals
« Reply #6 on: October 09, 2018, 12:16:24 AM »
Dont forget that there will be a voltage drop if anything is taking power e.g. coils, neutral/oil light etc. There should not be  that much of a drop on the red line with no load and with your results taken as is

That means the contacts in the switch are high resistance.
Option 1 fill it full of wd40 and work it a lot and retest

Option 2 if 1 does not work take switch apart and manually clean contacts and retest

Option 3  if neither 1 nor 2 work new switch
« Last Edit: October 09, 2018, 12:21:12 AM by Bryanj »

Offline cb550k-aaron

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Re: 1978 CB550 Electricals
« Reply #7 on: October 09, 2018, 09:12:24 AM »
Fair enough I might just take a punt on a new one tbh as I need it sorted out.

Another question, I installed the new wiring loom but for some reason I can't get the Starter button to work. I don't have a neutral switch or clutch switch and think that's the problem, do they need earthing or? Thanks again

Offline Bryanj

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Re: 1978 CB550 Electricals
« Reply #8 on: October 09, 2018, 04:03:15 PM »
Depends on if you have the starter safety box or diode fitted and also what year loom and switches as the operation changed

Offline cb550k-aaron

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Re: 1978 CB550 Electricals
« Reply #9 on: October 09, 2018, 07:20:31 PM »
There's a small 2 pin diode/rectifier thing is that what you mean?

The loom is for a 78 from David Silver and Switch is a replica of the Original with the Starter button and Red kill at the top and the Headlight modes.

If that's any help at all

Offline BigAl (Alan)

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Re: 1978 CB550 Electricals
« Reply #10 on: October 09, 2018, 07:23:40 PM »
Maybe I've not read the posts properly, but is your bike a CB550..K..or.. F  wiring looms are different
Current bikes:-
Honda CB750 K4 (1974) USA
Honda XL500S (1980) UK
Honda CD175 sloper (1968) UK
Honda CB1100A (2013) UK
www.alans-electrics.co.uk

Offline cb550k-aaron

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Re: 1978 CB550 Electricals
« Reply #11 on: October 09, 2018, 07:29:18 PM »
Maybe I've not read the posts properly, but is your bike a CB550..K..or.. F  wiring looms are different

It's a 550K3

Offline BigAl (Alan)

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Re: 1978 CB550 Electricals
« Reply #12 on: October 09, 2018, 07:44:27 PM »
The earlier CB550K had a 5 wire safety switch, its possible that the later CB550K3 had a 2 wire safety switch which was also fitted to the F model.
Have you fitted a diode (as image) to the 2-way socket?
Current bikes:-
Honda CB750 K4 (1974) USA
Honda XL500S (1980) UK
Honda CD175 sloper (1968) UK
Honda CB1100A (2013) UK
www.alans-electrics.co.uk

Offline cb550k-aaron

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Re: 1978 CB550 Electricals
« Reply #13 on: October 09, 2018, 07:53:28 PM »
The earlier CB550K had a 5 wire safety switch, its possible that the later CB550K3 had a 2 wire safety switch which was also fitted to the F model.

Have you fitted a diode (as image) to the 2-way socket?

Hi mate. Yes I used the old one from the Original wiring loom. It's as you have pictured there. If I measure the red and yellow wire attached to the starter Solenoid it's 0v until I hit the button it goes 12v+ but nothing happens.

Offline petermigreen

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Re: 1978 CB550 Electricals
« Reply #14 on: October 09, 2018, 09:19:37 PM »
If I measure the red and yellow wire attached to the starter Solenoid it's 0v until I hit the button it goes 12v+ but nothing happens.
That proves the starter button is doing it's job.
You could prove the solenoid by shorting across the two large terminals with a meaty screwdriver, if it doesn't turn the starter over then either the solenoid is duff or the starter is. If nothing happens right away pull away or you could do damage.
You could prove the starter by putting a jump lead directly from the battery positive onto the the heavy cable that goes to the starter motor.

 

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