Author Topic: Wiring - ready to hang myself by the harness! (Read 2033 times)

spmc · « **on:** July 01, 2015, 05:19:57 PM »

So I got a new set of mini gauges for my project and am trying to wire them up... I'm almost there I just can't seem to get it right. The speedo has a backlight and three indicator lights, neutral, high beam, and turn. The tach just has the backlight. And for an oil light I'm running a single red LED.

So I get everything to light up like it should the way it's shown in my makeshift diagram in the pic, yet I don't know where to wire the green red neutral ground... Any help would be much appreciated.

1977 cb750f, have the wiring diagram, still lost. Also I cut all the lights out of the gauge cluster and am soldering them to the aftermarket wires.

UPDATE BELOW (POST #9)

New can of worms opened up, not just a gauge problem any more!

calj737 · « **Reply #1 on:** July 01, 2015, 06:45:10 PM »

The stock Green/Red wire from the Neutral switch is a ground and the Green on your gauge is a current. Connect Gr/RD to one of the Blacks and the Neutral light should come on.

spmc · « **Reply #2 on:** July 01, 2015, 07:07:58 PM »

So you're saying I can wire the Neutral ground (green red wire) in with the black ground from the new gauge that connects to the three other green grounds from the stock harness? Or does it need to have it's own ground?

The reason I'm confused is because if I run one black ground from the New Speedo to the two green grounds from the old speedos backlight wires the new speedo lights up. But if I run those same green wires from the old back light in with the 3 greens from the old harness and one black from the new speedo the backlight does not light up.

This is what hurts my head! Unless the neutral ground from the old harness can be wired in with the grounds for the other indicator lights, I'm not sure how to get everything to light as it should. And to make matters harder I don't have the engine in yet so I can't really be sure it's all working as it should by firing it up just yet!

spmc · « **Reply #3 on:** July 01, 2015, 07:09:33 PM »

Thank you so much for the help by the way, I searched all over the place and can't seem to find the specific info I need. I promise if I get this wired and working correctly I will draw up an diagram for dummies using a non-DCC speedo.

calj737 · « **Reply #4 on:** July 01, 2015, 08:34:39 PM »

There was no "neutral ground" in the old harness. The Neutral wire is a ground and the stock gauge already had power to the light, but was relying on the switch (neutral) to be grounded and complete the circuit.

New gauge: Green to switched power (BR/WHT) and the stock GR/R to new BLK.

The thing that is throwing you off is the info lights in the new gauge are all "powered" by their respective feed wires (HI comes from a powered circuit) but the Neutral light is already powered by BR/WHT but not grounded.

spmc · « **Reply #5 on:** July 01, 2015, 10:27:05 PM »

After staring at multiple wiring diagrams and reading what you said over and over thinking I'm too dumb to get this, I'm thinking this might be the right way... I think including the oil light here is key as well cause I may have that wired wrong at the moment...

NEW GAUGE OLD HARNESS
YELLOW ---------------> LIGHT BLUE
YELLOW ---------------> ORANGE
BLUE ---------------> BLUE
RED ---------------> BROWN/WHITE (from the old Speedo Illuminating harness)
GREEN ---------------> BLACK WIRE
BLACK ---------------> 3 GREEN GROUNDS
BLACK ---------------> LIGHT GREEN/RED

OIL LED OLD HARNESS
RED ---------------> BLACK
BLACK ---------------> RED/BLUE

But then I'm stuck again because with this setup I don't know where to connect the two green ground from the speed illuminating backlight... If all is correct above, where do those go?

turboed13b · « **Reply #6 on:** July 01, 2015, 11:22:02 PM »

Does your neutral light have its own ground? If not you won't be able to wire it to the bike.

calj737 · « **Reply #7 on:** July 02, 2015, 04:17:56 AM »

Spmc - you can't get wrapped up in what was used in the stock harness. you only need to focus on what is required with the new gauge. the extra stock GREEN wires are unimportant to the new gauge.

I like the way you have it otherwise.

spmc · « **Reply #8 on:** July 02, 2015, 06:59:10 AM »

OK thank you very much! I'll try it out in a few hours and report back...

spmc · « **Reply #9 on:** July 02, 2015, 05:47:13 PM »

Well, somehow things got worse!

I switched the fuse block to a blade style setup as I already burnt through the three of the glass fuses and have read they're testy anyway. So after doing that I don't know whats going on because I can't even get the tach backlight or the headlight itself to actually go on. The turn signals work, but the tail light only illuminates when in P, not ON. I bought a tester and get a positive reading on the following:

Two black supply lines
Either side of the 15a fuse
Either side of the 7a fuse (I had to use a 7.5a fuse as they didn't have 7)

Everything else is no go, including either side of the 5a fuse even though the fuse is still good I can see it's still connected (also nothing on the brown/white, blue to headlight), and I don't even know where to start to problem solve. Any help in pointing me in the right direction is appreciated.

turboed13b · « **Reply #10 on:** July 02, 2015, 06:56:23 PM »

Since you have a multimeter you can test things instead of blindly plugging wires together.

Brown/white is fed by a brown/blue wire. The brown/blue wire is fed by a black wire which is probably connected somewhere in the headlight. I would look there as it may have been unplugged.

spmc · « **Reply #11 on:** July 02, 2015, 11:15:30 PM »

I'll start there tomorrow! Thanks for the info.

spmc · « **Reply #12 on:** July 03, 2015, 05:11:33 PM »

Falling further down the rabbit hole... Gonna post questions as I'm working so I can try to get this fixed!

It seems like this just leads to nothing... It's a black and brown/blue wire, the brown blue come from the left side controls and the black leads to the connection block for the left controls, but at the end it's just cut... Don't think I did that?

calj737 · « **Reply #13 on:** July 03, 2015, 05:21:02 PM »

Quote from: spmc on July 03, 2015, 05:11:33 PM

but at the end it's just cut... Don't think I did that?

I certainly hope not... The BLK is needed to carry power to the left side control switches.

spmc · « **Reply #14 on:** July 03, 2015, 05:37:13 PM »

Hmmmm, if you see in this new picture the black wire at the top left of the connection carries the power to the Clutch lever top right feeds the gauges, bottom right the horn and the bottom of the connection runs out, joins with the brown/blue and leads to nothing... While the other side of the brown/blue runs to the left side controls... Is it possible it was the second light in one of the gauges?

spmc · « **Reply #15 on:** July 03, 2015, 06:00:06 PM »

Also, got these bad boys coming from the loom (?) that runs through the bottom triple.... Brown/blue leads to a connection alongside black, right now I got nothing connected to that, and then a green leading to a 2 sided female connection, nothing running to that... Any ideas what should be connected there? If anything?

Annnnnd just found a brown wire with a Covered female connection with nothing going to it coming from the same loom....

Thanks so much for the help guys, I feel bad not being able to find it on searches or make sense of the diagrams!

spmc · « **Reply #16 on:** July 03, 2015, 06:41:40 PM »

Okay I figured out what I did wrong, my wires were out of place on the fuse panel, the 5a and 7a were switched, switched back and now ready to start tackling the gauges again!

Funny how a tester can help you get where you need to go!

turboed13b · « **Reply #17 on:** July 03, 2015, 06:50:27 PM »

Looks like someone has been messing around in there so looking at the diagram has been thrown out of the window lol.

A brown/blue and black wire are used for the turn signal buzzer. I am going to take a guess those are the cut wires. If your bike doesn't make an annoying buzzing sound when signals are on then someone has unplugged it. Trace the wires back and it should end up at the buzzer.

You need to check for continuity for a brown/blue wire. Hold one probe at the fuse box location and test each brown/blue wire with the other probe and find the one that has a reading. When you find the correct brown/blue wire this is the one that is suppose to connect to black.

EDIT: looks like you got it going.

Since you got the meter check to see if the neutral light has its own ground. If it doesn't and it shares it with the other lights you won't be able to wire it up.

spmc · « **Reply #18 on:** July 03, 2015, 07:18:29 PM »

you my good man are a genius... That's gotta be what that is, buzzer! Now that everything is powering I'm at the gauges again and it looks like you might be right about the neutral not being able to be wired up...

With everything wired as listed above I'm left with the following exposed...

Two blacks from new gauge

Three grounds (headlight and turns) from harness
Light green/red from harness
Two grounds from speedo illuminating harness

So I can achieve this
With a black going to the two greens the gauge illuminates and the other black to the three greens the turn and headlight work and the neutral light is on but the lg/r wire is left mate less

How could I test for an independent ground? I just have a screwdriver with a clip style tester

spmc · « **Reply #19 on:** July 03, 2015, 07:22:41 PM »

Also the oil light doesn't go on wired as is at the moment, but does when I add in a ground from somewhere else, so I assume that's correct and when the engine is installed the switch will work as it should?

turboed13b · « **Reply #20 on:** July 03, 2015, 08:14:37 PM »

Unplug the black ground from the three greens. The neutral light will turn off. Does the backlight, turn, or high beam light turn off also? If so then the ground is shared with the other light that turns off.

The oil light will work correctly when the engine is installed.

Actually rereading what you put it looks like one black ground is for the backlight and the other black ground is for neutral, high, and turn. So it looks like you won't be able to use the neutral light.

mystic_1 · « **Reply #21 on:** July 03, 2015, 08:18:55 PM »

Another option would be to use a small SPST relay to drive your neutral light.

1. Run +12 to one side of the relay's trigger coil, connect the other side to your neutral switch. Now the relay will activate when you are in neutral.
2. Next, run +12 to one side of the relay's switched circuit, and run the other side up to your light.
3. ? ? ?
4. Profit!

mystic_1

turboed13b · « **Reply #22 on:** July 03, 2015, 08:25:09 PM »

Quote from: mystic_1 on July 03, 2015, 08:18:55 PM

Another option would be to use a small SPST relay to drive your neutral light.

1. Run +12 to one side of the relay's trigger coil, connect the other side to your neutral switch. Now the relay will activate when you are in neutral.
2. Next, run +12 to one side of the relay's switched circuit, and run the other side up to your light.
3. ? ? ?
4. Profit!

mystic_1

This will work!

spmc · « **Reply #23 on:** July 03, 2015, 08:36:50 PM »

Thanks so much for the info guys... and the scenario you described is correct, Neutral, turn and headlight all go on at the same time, and go off when I take away the three greens... so if I leave the neutral wire from the new gauge attached to the black from the harness the Neutral light will just constantly stay on then?

Quote from: mystic_1 on July 03, 2015, 08:18:55 PM

Another option would be to use a small SPST relay to drive your neutral light.

1. Run +12 to one side of the relay's trigger coil, connect the other side to your neutral switch. Now the relay will activate when you are in neutral.
2. Next, run +12 to one side of the relay's switched circuit, and run the other side up to your light.
3. ? ? ?
4. Profit!

mystic_1

Mystic I like the ingenuity of what you're saying, but I have NO IDEA what you're talking about, haha. Let me see if I can piece it together without looking completely stupid...

you're saying run a wire (not sure what +12 means) from the relay trigger coil to the Light Green/Red wire of the harness, then run another wire from the relays switched circuit to the neutral wire of the new gauge?

If so, could you please tell me what part of the relay is the trigger coil, and which is the switched circuit? And what "Run +12" means... sorry I'm so ill informed!

spmc · « **Reply #24 on:** July 03, 2015, 08:40:05 PM »

And because the hits just keep on coming I couldn't get the horn to go! I checked the controls inside and it all looked in order... I'm getting power to the black wire that leads to the horn and the sort of mint green wire run into the headlight, into a connection with another mint green wire that then runs up to the controls.... So I have no idea why it wouldn't be honkin'

turboed13b · « **Reply #25 on:** July 03, 2015, 09:12:30 PM »

The horn is ground switched. The button contacts inside the switch probably need cleaned. I just did that yesterday for a friends bike.

If you leave the black wire connected to the green wire the neutral light will just stay on.

To add a relay:
-Black from harness to 85 on relay. Any black will work they are all power.

-Light green/red to 86

-Black from harness to 30. Again any black will work.

-New neutral light green to 87.

You can use a standard automotive relay there is enough space to fit in the bucket.

mystic_1 · « **Reply #26 on:** July 04, 2015, 07:43:35 AM »

Exactly as described by turboed13b.

"Run +12" meant "connect a wire which provides 12 volts". As turboed13d said, tap any black wire in the harness for this.

Automotive-style relays have standard pinout numbering. The trigger coil is the electromagnet inside the relay that controls the switched circuit (terminals 85 and 86). The switched circuit is just what is says on the tin, the circuit that is opened/closed by the trigger coil (terminals 30 and 87).

When the neutral switch closes (in neutral) this will energize the trigger coil which will close the switched circuit, allowing 12 volts to flow from the harness into the new neutral light.

spmc · « **Reply #27 on:** July 07, 2015, 05:11:53 AM »

Just wanted to update and thank you guys, got the relay in place and everything works as it should! GREAT workaround!

mystic_1 · « **Reply #28 on:** July 08, 2015, 04:57:04 AM »

Excellent, glad you got it sorted!

mystic_1

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Author Topic: Wiring - ready to hang myself by the harness! (Read 2033 times)