Author Topic: CB550F wiring harness questions (Read 4584 times)

Scott S · « **on:** April 12, 2019, 09:14:46 AM »

Working on a 550F and have some questions about where the handle bar controls connect at the junction box, under the coils.

I picked up a new, aftermarket LH control that is supposed to be correct for this bike, but there are two wires that I can't make sense of.

But first: There's a Brown/Blue wire that is looped back into a Black plug. Br/B is for the turn signal buzzer, which I will leave omitted. There's also a Br/B with Yellow tube.
Is this just where someone bypassed the turn signal buzzer? Is this OK?

BROWN/BLUE plugged into BLACK

BROWN/BLUE with YELLOW tube

Scott S · « **Reply #1 on:** April 12, 2019, 09:27:03 AM »

Most of the other wires are easy

LIGHT GREEN for horn
GREY for flasher relay
ORANGE & ORANGE/WHITE for LH turn signal
BLUE & BLUE/WHITE for RH turn signal
BROWN/WHITE that goes to ignition switch (I assume this is on the LH control because of the clutch safety switch? Allows power to ignition when clutch switch is pulled in?)

WHITE for headlight
BLUE for headlight

There is a BLACK/YELLOW on the main harness that goes to the 7A fuse for the headlight. I don't have a BLACK/YELLOW on the aftermarket harness.

What I DO have is a BLACK/RED stripe, but that is shown in the wiring diagram as being on the RH control as part of the "engine stop-starter switch". It also goes back to the 7A fuse for the headlight.
I have the BLACK/RED from the RH switch plugged in already.

Also shown in that pic is a BLACK/BROWN stripe wire. I can't find that on the diagram.

Any idea what these are for?

Scott S · « **Reply #2 on:** April 12, 2019, 09:27:38 AM »

And the 550F diagram:

Scott S · « **Reply #3 on:** April 12, 2019, 09:38:58 AM »

I opened up the LH control and it appears that the BLACK/RED goes to the Hi/Lo switch for the headlight.
The BLACK/BROWN appears to go to the turn signal switch.

What would be the corresponding wires on the diagram I posted above?

Scott S · « **Reply #4 on:** April 12, 2019, 09:54:51 AM »

And while we're at it: This bike came to me with a Dyna ignition. I assume I can connect the BLUE and YELLOW to the points wires on the RH side of the bike, near the air box and rear brake switch wires.
The RED.... just make a jumper to attach to the BLACK power wire right there at the rear brake switch?

Scott S · « **Reply #5 on:** April 12, 2019, 03:55:06 PM »

Anybody?

TwoTired · « **Reply #6 on:** April 12, 2019, 05:04:31 PM »

BR/B should connect to BR/B with that yellow connector. The turn buzzer should have its own black wire routed to it.
Like color coded wires usually connect to each other.

My wire diagrams don't show any Bk/red wires to/from the LH control, only Bk/Y. Does your control have a headlight dip function like euroversions?
Bk/Y connects to the PR terminal.

Do you have a BK/Y on your fuse block? What does it connect to?

Scott S · « **Reply #7 on:** April 12, 2019, 06:18:18 PM »

Quote from: TwoTired on April 12, 2019, 05:04:31 PM

BR/B should connect to BR/B with that yellow connector. The turn buzzer should have its own black wire routed to it.
Like color coded wires usually connect to each other.

My wire diagrams don't show any Bk/red wires to/from the LH control, only Bk/Y. Does your control have a headlight dip function like euroversions?
Bk/Y connects to the PR terminal.

Do you have a BK/Y on your fuse block? What does it connect to?

I won't be running the turn signal buzzer. I guess that's just how they bypassed it? No need for the BR/B to be connected to BLACK, is there?

My diagram doesn't show any BLACK/RED on the LH switch either. I guess since the BLACK/RED is coming from the Hi/Lo switch then it should probably connect to the BK/Y for the headlight fuse?
There is a Bk/Y on the fuse block but I cant tell where it goes. According to the diagram, it's for the headlight fuse.

What would the BLACK/BROWN coming from the turn signal switch be for?

TwoTired · « **Reply #8 on:** April 12, 2019, 10:03:51 PM »

Which year model do you have?

If I understand correctly, your blinkers won't flash if you connect BR/B to black. They'll just stay on regardless of power coming from the flasher unit.

But if you don't run black to the buzzer, it won't buzz. IF you want the OPTION of connecting a buzzer later, connect the BR/B male to the BR/B female.

The Black red from the RH control runs back to the HL fuse. The other side of the fuse, is BK/Y, which runs to the LH switch group, where H/L is selected. And routed to either the white or Blue wires to Headlight.

None of my Honda Wire diagrams show a BLACK/BROWN for the LH control group. You'll have to buzz it out or take it apart to see what connections in provides.

Cheers,

Scott S · « **Reply #9 on:** April 13, 2019, 04:35:39 AM »

Bike is a 1975 CB550F. It came to me without a wiring harness or controls. I picked up a used F-model wiring harness and aftermarket controls. I looked up the part #'s for the controls and these are supposed to be correct for an F model.

I though that the RH control is fine, but upon closer examination it too has a BLACK/BROWN wire that I don't know where it goes. I thought it was pure BLACK, but it's not.
The LH control has those two wire colors that don't match the harness.

It's obvious that power needs to be fed to the headlight switch. You said that "The Black red from the RH control runs back to the HL fuse. The other side of the fuse, is BK/Y, which runs to the LH switch group, where H/L is selected. And routed to either the white or Blue wires to Headlight."
My RH switch doesn't have a headlight switch. Only the kill switch and the starter button. All of the headlight controls are on the LH switch.

I guess I need to open up the RH switch and see where the BLACK/RED and BLACK/BROWN are feeding from as well. If I can understand the function of those wires I can probably figure out where to route them.

Scott S · « **Reply #10 on:** April 13, 2019, 04:41:26 AM »

My diagram shows the BLACK/RED and YELLOW/RED on the RH switch going from the starter button to the starter motor solenoid. That same BLACK/RED is routed to the 7A fuse for the headlight (?).

Scott S · « **Reply #11 on:** April 13, 2019, 05:04:08 AM »

Quote from: Scott S on April 12, 2019, 09:27:38 AM

And the 550F diagram:

In the bottom left section of this diagram is the LH control, labeled "headlight dimmer-turn signal switch".
Can anyone help me read and understand the tiny abbreviations?

B = buzzer? (I'm eliminating this)
Lo = Goes to white wire, so Low beam
Hi = Goes to blue wire, so Hi beam
HL = Goes to Bl/Y, which goes to the headlight fuse on the fuse box, so headlight power?
R = Goes to LB, which is RH turn signal
L = goes to Orange, which is LH turn signal
W = Grey, goes to "winker relay"
PR = LB/W, so that's the "parking light, right" or the RH running light (won't be using)
PL + O/W, so "parking light, left", or LH running light
TI(?) = I think that's an I. Brown/White, goes to ignition switch. Turn Indicator power?
H = horn
E = earth? It's a ground, with no wire color showing.

If I can identify and eliminate the running lights and the buzzer, I have all of the other wires connected properly.
I just need to identify what the BLACK/RED and BLACK/Brown are for.

Yamahawk · « **Reply #12 on:** April 13, 2019, 05:25:59 AM »

Scott,
I don't have a CB550, but on the 1974 CB750 harness I used, it had two bullet connectors that were not used at all. Matter of fact, when I removed the factory wrap, and re-wrapped the harness, I found those two wires were not hooked to ANYTHING in the harness! I agree with Lloyd, ohm them out, and see were they go, if anywhere. Are you absolutely sure that the harness you got used is really a 1975 CB550F harness?
Charlie

Scott S · « **Reply #13 on:** April 13, 2019, 05:29:56 AM »

Okay, here's what I'm thinking...

On the LH switch, the BLACK/RED coming from the Hi/Lo switch is the same as BLACK/YELLOW and is what feeds fused power to the headlight dimmer switch.

The BLACK/BROWN is coming from the turn signal switch and is probably the same as the BROWN/BLUE that feeds power to the buzzer when the switch is activated.

I moved the buzzer jumper wire they had in there and just made a loop on the BROWN/BLUE wire.
I connected the BLACK/BROWN from my LH control to BLACK for power to the turn signals..... correct? TwoTired, you said the signals need that to flash....right?

Also, that extra BLACK/BROWN on the RH control goes to the starter button. It isn't shown on my diagram and all other wires on the RH control are accounted for. Maybe just leave it unplugged until I can get a battery and start doing some testing?

Scott S · « **Reply #14 on:** April 13, 2019, 05:31:11 AM »

Yes, I'm sure the harness is a correct F model harness. It has the connections for the junction box under the coils.

Scott S · « **Reply #15 on:** April 13, 2019, 06:08:05 AM »

Quote from: Yamahawk on April 13, 2019, 05:25:59 AM

Scott,
I don't have a CB550, but on the 1974 CB750 harness I used, it had two bullet connectors that were not used at all. Matter of fact, when I removed the factory wrap, and re-wrapped the harness, I found those two wires were not hooked to ANYTHING in the harness! I agree with Lloyd, ohm them out, and see were they go, if anywhere. Are you absolutely sure that the harness you got used is really a 1975 CB550F harness?
Charlie

Yeah. It makes sense that the BLACK/RED is the same as the BLACK/YELLOW that feeds fused power to the headlight switch. That's one color that is missing from the LH control (BLACK/YELLOW).
Those two BLACK/BROWN wires on each control are weird and I'm not sure where they would go. The diagram only shows two wires going to the starter button, not three. And I'm not sure why the turn signal circuit in the LH control needs that extra wire, either.

TwoTired · « **Reply #16 on:** April 13, 2019, 11:34:18 PM »

Its late and I am pretty tired. So, I'll just say this now. The right hand control starter button interrupts the power to head light when button pushed.
The switch is a rocker, routing power to bk/r or y/r from the black wire depening on button position.

You controls don't have color codes matching Honda diagrams. You'll have to buz out what you have to determine functions and what wire does what.

Cheers,

Scott S · « **Reply #17 on:** June 04, 2019, 10:55:33 AM »

Got a battery in and it looks like I was correct on connecting the mystery wires. Everything at the front of the bike works. Mostly.

I have headlight Hi and Lo.
All dash lights and idiot lights work.
Front turns light up but don't flash (yet).
Horn beeps, weakly.

But I dont have power at the rear of the bike. I'm not getting any power to the brown wire that feeds the tail light, or to the rear turn signals.
Checked the fuse and it's good. I have power at the main fuse and headlight fuse, but no power to the taillight fuse.
All connections look good. Fuse holder looks good. Solder on back looks good.
How do I go about tracing out the BROWN/BLUE and BROWN/WHITE wires for the taillight circuit?

I don't have the front master cylinder on yet, so that wiring isn't connected, but I should still have power to the fuse, right?

Scott S · « **Reply #18 on:** June 04, 2019, 11:06:46 AM »

I partially answered my own question. I had the BROWN/BLUE looped on the line with the Yellow tracer. That's the circuit for the turn signal beeper, which I won't be using. Supplied power to the BROWN/BLUE by connecting it to BLACK, per the diagram, and I have brake and tail light.

No rear signals yet, but I'll work on that.

And I haven't checked for spark yet, though I did spin it over enough to make the oil light go out.

Scott S · « **Reply #19 on:** June 04, 2019, 11:09:08 AM »

And I need to order a new POS battery cable. The one I found in my stash is too short to actually bolt to the battery, though I can touch it to the terminal for testing.

Scott S · « **Reply #20 on:** June 09, 2019, 08:12:34 AM »

Moved the BLACK/BROWN on the RH control to BLACK and now I have spark as I should.

So, for future reference, those mystery BLACK/BROWN wires go to BLACK for switched power.

TwoTired · « **Reply #21 on:** June 09, 2019, 08:56:55 AM »

Quote from: Scott S on June 09, 2019, 08:12:34 AM

Moved the BLACK/BROWN on the RH control to BLACK and now I have spark as I should.

So, for future reference, those mystery BLACK/BROWN wires go to BLACK for switched power.

On a stock bike? Or, a hybrid wire harness/controls?

Scott S · « **Reply #22 on:** June 09, 2019, 09:28:04 AM »

Well..... both. Sorta.

It's a 550F and it came to me with no wiring harness or controls.
I found a good, used F model harness. I couldn't find any good F model controls at the time so I cross referenced the part numbers. Found a RH control from a Goldwing that was being parted out locally. Found a reproduction LH control on Ebay that had the same part # as the F model.
But when I got them in hand, both had that extra BLACK/BROWN wire that isn't shown on the F model wiring diagram. Everything else matched up.
The length on the Goldwing control was good, but the LH control was short for an F model. Probably would have fit in the headlight bucket just fine. I used Super Bike bars and notched the front of the junction box under the tank to get the LH side to fit. Definitely would have been too short for stock bars.

News:

Author Topic: CB550F wiring harness questions (Read 4584 times)