Author Topic: Was there a Light switch on the 1974 CB750? (Read 2287 times)

redbug2 · « **on:** January 04, 2018, 01:58:38 PM »

Hello,

Working on a 1974 CB750.

Previous owner butchered the old switch harnesses in his attempt to put ape hangers on the bike. I'm trying to bring it back to stock but I don't see a headlight control switch on the right controls as shown in my clymer manual wiring diagram.

Maybe previous owner switch out the controls to a non-switch control?

I see the left side has a high low switch. Would that have an off position?

Also, a little confused about the turn signal indicator on the handlebars. I guess it grounds in the switch. Are there any pictures on the net of the wiring in the headlight? I can't make sense of the clear and white female shielded blue and orange connectors.

Thanks in advance for any information.

Regards,

redbug2

evinrude7 · « **Reply #1 on:** January 04, 2018, 03:52:35 PM »

i haven't verified that this is absolutely correct but here... https://www.cmsnl.com/classic-honda-fansite/honda_wiring_diagrams/CB750(K3-K7).jpg

Stev-o · « **Reply #2 on:** January 04, 2018, 04:18:13 PM »

Quote from: redbug2 on January 04, 2018, 01:58:38 PM

Hello,

Working on a 1974 CB750.

I see the left side has a high low switch. Would that have an off position?

My K4 has an on/off headlight switch on the RH control.

TwoTired · « **Reply #3 on:** January 04, 2018, 04:59:47 PM »

Quote from: Stev-o on January 04, 2018, 04:18:13 PM

Quote from: redbug2 on January 04, 2018, 01:58:38 PM
Hello,

Working on a 1974 CB750.

I see the left side has a high low switch. Would that have an off position?

My K4 has an on/off headlight switch on the RH control.

And a Hi-Lo switch on the left, correct?
That's the way my 74 Cb550 is, anyway.

Cheers,

DV Red Herring · « **Reply #4 on:** January 04, 2018, 05:52:17 PM »

Quote from: TwoTired on January 04, 2018, 04:59:47 PM

Quote from: Stev-o on January 04, 2018, 04:18:13 PM
Quote from: redbug2 on January 04, 2018, 01:58:38 PM
Hello,

Working on a 1974 CB750.

I see the left side has a high low switch. Would that have an off position?

My K4 has an on/off headlight switch on the RH control.

And a Hi-Lo switch on the left, correct?
That's the way my 74 Cb550 is, anyway.

Cheers,

This how my K4 is set up as well. The Hi/Lo is on the left side switch.

Yamahawk · « **Reply #5 on:** January 04, 2018, 06:39:56 PM »

Quote from: redbug2 on January 04, 2018, 01:58:38 PM

Hello,

Working on a 1974 CB750.

Previous owner butchered the old switch harnesses in his attempt to put ape hangers on the bike. I'm trying to bring it back to stock but I don't see a headlight control switch on the right controls as shown in my clymer manual wiring diagram.

Maybe previous owner switch out the controls to a non-switch control?

I see the left side has a high low switch. Would that have an off position?

Also, a little confused about the turn signal indicator on the handlebars. I guess it grounds in the switch. Are there any pictures on the net of the wiring in the headlight? I can't make sense of the clear and white female shielded blue and orange connectors.

Thanks in advance for any information.

Regards,

redbug2

On my harness that I am using, it has the clear and white end covers in the headlight shell, on the orange and lt.blue wires(usually turn signal colors). I found these were not actually connected inside the wiring harness, as when I removed the wrapping on it, I found they were just laid in there, and were not actually connected to the harness. They must be extra wiring for some kind of option, like flashers, used on perhaps a Police bike or something, but weren't implemented on my harness. I believe my harness is a 1974 also, it came in a bin of parts, and I decided to use it. The starter safety module is connected by a red 6 pin connector on this harness also.
You do have other wires that are orange and lt.blue, use those for the turn signal wiring, and not the half white/clear wire ends. I am attaching a picture showing the wires in question, not hooked up.
Charlie

DV Red Herring · « **Reply #6 on:** January 04, 2018, 07:11:56 PM »

I used the extra blue and orange leads to trigger the turn signal indicator on the bar clamp.

carnivorous chicken · « **Reply #7 on:** January 04, 2018, 07:14:23 PM »

Extra blue and orange could be for a deleted turn signal buzzer, although '74 is a bit early. And if I'm not mistaken, '75 was when Honda started deleting the off/on switch for headlights but some 75's have 'em, some don't. Again, IIRC...

disco · « **Reply #8 on:** January 04, 2018, 07:30:17 PM »

I thought the extra orange/white & light blue/white were for the daytime ‘running lights’ that are used (or were used ?) on turn signals in USA?

I’m in Aus & we don’t use daytime running lights,so I just ignored those two wires in the repro harness, when I recently did mine. All works good for me.

Yamahawk · « **Reply #9 on:** January 05, 2018, 02:42:14 AM »

Quote from: DV 750 on January 04, 2018, 07:11:56 PM

I used the extra blue and orange leads to trigger the turn signal indicator on the bar clamp.

Were they live or did you have to attach them? Mine were 'dead' as they had never been attached inside the harness. The lt.blue wire was folded in a hook shape, and the orange was straight, but never attached to the harness, as my picture shows. I may unwrap the harness again, and attach them to the turn signal wiring, in case i need more attachment points for the turn signal indicator also since I have the lights on the handlebar clamp too.
Charlie

DV Red Herring · « **Reply #10 on:** January 05, 2018, 09:07:05 AM »

Mine had been used previously, but at the time I got the bike the wiring was a rats nest. Using a wiring diagram I was able to get it all dialed in.

DV Red Herring · « **Reply #11 on:** January 05, 2018, 09:18:21 AM »

I'm not positive, but I think these bikes had parking lights? Maybe that explains why yours were unused? I do know that using the stock wiring harness I was able to attach front and rear turn signals and the indicator all inside the headlight bucket.

redbug2 · « **Reply #12 on:** January 05, 2018, 01:09:02 PM »

Thanks for the posts, they have been informative. I certainly have the wrong RH switch. The bike did have a rigged toggle switch in the headlight so I guess that's how the PO got around having the wrong switch.

Good to know that the two wires I've been scratching my head about are inert. Maybe I'll use the two female connectors in each as a coupling.

I'm going to tackle the turn signal indicator next. Since that light has an orange and blue wire going to it I assume its meant to take either right or left current and the switch will ground it. Orange on, blue is ground. Blue on, Orange is ground. ...?

Going to have another crack at it soon... Just having a cold snap here in Pennsylvania, -12 F wind chill tomorrow. My barn is unheated and I can only take about an hour before my toes get cold!

Regards,

Redbug

Yamahawk · « **Reply #13 on:** January 05, 2018, 01:51:27 PM »

I am thinking that the orange is left turn, light blue is right turn... green is ground. What part of PA are you from? My youngest daughter and her husband live just across the line in Sharpsville, Hermitage area. I also lived in Shrewsbury in York County, in H.S.
Charlie

Stev-o · « **Reply #14 on:** January 05, 2018, 02:35:36 PM »

Quote from: DV 750 on January 05, 2018, 09:18:21 AM

I'm not positive, but I think these bikes had parking lights?

The K4 has a park light, the tail light.

The ignition has 3 positions: 1.off 2.on 3. park. I've never used it.

Of course we are talking stock here, who knows what has been changed on his bike over the years?

redbug2 · « **Reply #15 on:** January 05, 2018, 03:06:00 PM »

I'm in Southeastern PA. Pottstown.

Sorry if this is long, just thought I would share my findings for the Dash turn indicator.

Figured it out.... Here's my take on the situation. The front bulbs are double filament. They are passing current through both sets of Filament's. So, Positive going to light the bulb for one filament and I believe the other is used to pass ground back through.

Two wires into the front turn signals. Shell is ground. For the Left front turn there is one black wire with a small blue plastic collar and another black wire with a blue collar plus a white collar.

Dash panel Turn signal indicator has orange and blue wires. No dedicated ground.

Coming out of the witch harness you have 4 wires that matter for the turn signals. Orange, Blue, Orange and white, blue and white.

I'll just comment on what happens on the left orange side, same setup for right, just blue.

I took the orange wire from the switch and put that in the orange multi female connector. Any black with orange collar also was plugged into the multi connector. I also took the dash indicator solid orange wire and put it into the orange multi connector.

I took the black wire from the turn signal with ORANGE AND WHITE collar and put that into the inert orange wire double coupler with the white and clear plastic shield. I then took the Orange with white strip wire from the switch and put it in the white and clear plastic shield.

For orange, when you turn the switch to the left it sends 12v down the orange wire energizing the signals (one filament on the front) and energizing the orange dash indicator wire. At the same time the switch then also grounds the blue wire with white strip which grounds the filament on the right turn sending ground into the blue multi coupler in turn sending ground to the blue dash indicator wire......

I also found the original RH switch with headlight on/off. It's butchered. I may take the time to repair it or I may just put in a toggle switch.

Regards,

redbug

Yamahawk · « **Reply #16 on:** January 05, 2018, 05:44:53 PM »

Hmmm.... so the Orange/White/Clear and lt.blue/White/Clear shielded bullet female connector wires are just used as a hub connector for the extra wires to the dash light?It might be why they just terminate in the harness without being hooked up to the harness...
Charlie

Yamahawk · « **Reply #17 on:** January 05, 2018, 05:53:48 PM »

Here is the switch I used for throttle side with on/off switch, it is for the 74-76 models I believe.
https://www.ebay.com/itm/Honda-CB750-Switch-Assembly-Right-Brake-Side-OEM-Ref-35300-341-671/201755877473?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m2749.l2649
Charlie

TwoTired · « **Reply #18 on:** January 05, 2018, 06:09:09 PM »

Quote from: Yamahawk on January 05, 2018, 05:44:53 PM

Hmmm.... so the Orange/White/Clear and lt.blue/White/Clear shielded bullet female connector wires are just used as a hub connector for the extra wires to the dash light?It might be why they just terminate in the harness without being hooked up to the harness...
Charlie

The Org/wht and lt. Blue/white wires are power routing for the running/ position lights filaments, sourced at the bar switch. The dash turn indicator gets a connection to the org and lt blue wires. It will illuminate when either the right or left signal lamp is lit because the switch grounds the not lit signal lamp. Ergo the indicator blinks with whatever signal is blinking.

When the bright signal filament is lit, the dim run filament is unpowered. This is so it will flash bright to dark instead of bright to dim.

This is how the stock left hand bar switch controls lighting. Your link points to a right side bar control, which controls general lighting aside from the turn sigs.

Cheers,

754 · « **Reply #19 on:** January 05, 2018, 06:58:48 PM »

I think in 75 lights on became mandatory.. 74 as far as I know, last year of the switch..

Yamahawk · « **Reply #20 on:** January 06, 2018, 03:40:58 AM »

Quote from: TwoTired on January 05, 2018, 06:09:09 PM

Quote from: Yamahawk on January 05, 2018, 05:44:53 PM
Hmmm.... so the Orange/White/Clear and lt.blue/White/Clear shielded bullet female connector wires are just used as a hub connector for the extra wires to the dash light?It might be why they just terminate in the harness without being hooked up to the harness...
Charlie

The Org/wht and lt. Blue/white wires are power routing for the running/ position lights filaments, sourced at the bar switch. The dash turn indicator gets a connection to the org and lt blue wires. It will illuminate when either the right or left signal lamp is lit because the switch grounds the not lit signal lamp. Ergo the indicator blinks with whatever signal is blinking.

When the bright signal filament is lit, the dim run filament is unpowered. This is so it will flash bright to dark instead of bright to dim.

This is how the stock left hand bar switch controls lighting. Your link points to a right side bar control, which controls general lighting aside from the turn sigs.

Cheers,

Yep, thats good to know, but the wires I was referring to and kinda confusingly, are the ones in the picture I posted, that have no connection down inside the harness. If you look at the pic, the ends are female double bullets, and have a half clear and half white covering on the double female bullet connectors. The lt.blue one is bent double at the harness end, about 1" and didn't connect to anything at that end, where the orange one with the clear/white cover at its female double bullet is straight and also didn't connect at its other end inside the harness... I thought that was peculiar.

Quote

I also found the original RH switch with headlight on/off. It's butchered. I may take the time to repair it or I may just put in a toggle switch.

As for the link it is because the OP has a butchered rt. hand switch, and I gave him a link to the one I ordered.
Charlie

KeithB · « **Reply #21 on:** January 06, 2018, 06:50:27 AM »

Quote from: TwoTired on January 05, 2018, 06:09:09 PM

When the bright signal filament is lit, the dim run filament is unpowered. This is so it will flash bright to dark instead of bright to dim.

This is how the stock left hand bar switch controls lighting. Your link poin
Cheers,

Quote from: TwoTired on January 05, 2018, 06:09:09 PM

Quote from: Yamahawk on January 05, 2018, 05:44:53 PM
Hmmm.... so the Orange/White/Clear and lt.blue/White/Clear shielded bullet female connector wires are just used as a hub connector for the extra wires to the dash light?It might be why they just terminate in the harness without being hooked up to the harness...
Charlie

When the bright signal filament is lit, the dim run filament is unpowered. This is so it will flash bright to dark instead of bright to dim.

This is how the stock left hand bar switch controls lighting. Your link points to a right side bar control, which controls general lighting aside from the turn sigs.

Cheers,

This is done by a "breaking" contact in the LH switch.
There are a pair of wires in that switch loom that go to the turn signal filaments and a different pair that go to the "running" light filaments.(front only)
When you switch on the signals, the contact to the "running" lights is broken.
It makes for more wiring and the signals will work just fine without the "running" lights. (not parking lights!)

It's always easier to have an electrical schematic to work from.

mrbreeze · « **Reply #22 on:** February 10, 2018, 09:20:08 AM »

I'm in the process of putting my bike back together and having trouble understanding how the wiring for the turn signals works. I have all my signals working but the indicator only works on the left side. I had it working before but I don't recall what I did to do it. I recall having to jump something. I'm not running my front markers so the blue and orange with white stripes aren't being used. I have aftermarket signals front and back. The fronts don't have the grounding rings in the bucket. the ground wires on each side run to one of the ground buses on the main harness. I am having a hell of a time trying to get my brain around how the indicator bulb switches to ground the circuit when going to right turn position. Do I need to do something with those wires with the white stripes? My bike is a 1975 USA 750K with a born on date of 9-74 and has the headlite on/off switch on the right control.

Don R · « **Reply #23 on:** February 10, 2018, 10:49:33 AM »

I go to old man Honda and print out the color wiring diagram on two sheets of paper, then tape them to a piece of cardboard so I can stand it up and refer to it while I work.

HondaMan · « **Reply #24 on:** February 10, 2018, 11:15:44 AM »

The post-1973 CB750 lacks an Off-On switch for the headlight. It is only Hi-Lo, with a START button that disconnects the headlight during electric start cycle.

News:

Author Topic: Was there a Light switch on the 1974 CB750? (Read 2287 times)