Final electrical issues HELP!

[bill in okc]

I found these:

https://www.superbrightleds.com/cat/ba9 ... 2,100,3744" onclick="window.open(this.href);return false;:

[Coyote]

My best guess is a voltage leak somewhere. Kill switch 'off' key on and off, the lamp stays lit, BUT gradually dims. In 3 or 4 minutes you can barely see it. I don't know that it ever goes completely out as I haven't waited to see. I still have that open orange wire in the headlight shell. It has no mate. I have checked that wire to ground and it shows full battery voltage with the key on so I know it supposed to go somewhere.

[markush]

Hi again!

.... the lamp stays lit, BUT gradually dims. In 3 or 4 minutes you can barely see it. I don't know that it ever goes completely out as I haven't waited to see....

Then it sounds like a condenser somewhere in the wiring is loaded when ignition key is switched on, and discharging slowly over the (ultra low current ?) LED-Neutral-Lamp when switching off. If you turn the kill-switch on it will be discharged rapidly by the small resistance of the ignition coils and the neutral light goes out, the same with the brake lamp switch. Is there any aftermarket device mounted, which could contain a condenser? Otherwise, I only know of one larger capacitor sitting in the original flasher-relay. But that can not actually be the cause, I think. Nevertheless, you can disconnect the relay and do the test again.

...I still have that open orange wire in the headlight shell. It has no mate. I have checked that wire to ground and it shows full battery voltage with the key on so I know it supposed to go somewhere.

You have one orange wire free. The horn doesn't work. The horn should be connected to one terminal directly with orange. Maybe these facts belong together? Is there power on the "orange" terminal of the horn when the ignition switch is set to on? Is there ground on the "green" terminal of the Horn when the horn button is pushed? Or does the horn when the "green" terminal is connected to ground with a wire?

Markus.

[Coyote]

The horn wires are ganged together and they are the only 2 wires in the harness with spade connectors. You can't mix them up. I can't get any voltage or continuity to ground. Meter just floats in all instances. The horn and it's mount have full continuity the ground. We set the meter to ohms and checked between the 2 horn wires. That was last week so I don't remembe the numbers, but the readings were the same with no button and button pushed, key on and key off. It acts all the world like the switch is bad. We opened it up twice and it is doing it's thing inside.
There are no ad-on's to the harness that would contain a capacitor. The only change I made was to add a modern fuse. Those old glass fuses and their cheesy holders can be problematic themselves. I changed to modern blade fuses on my last 550 and the Buffalo I had. Oh well, tomorrow is another day.

[Coyote]

On the horn button, shouldn't one of the two wires go to ground when the button is pressed? Wire colors are orange and green. Should the orange wire have 12V when the key is on?

[bill in okc]

Disconnect the two horn wires. With the key on, meter set to DC volts, you should measure 12V on the orange wire. Turn the key off and voltage should drop to 0. Set the meter to ohms. With the key on or off the green wire should measure infinite resistance to frame ground/battery ground. Then press the horn button and the resistance should drop to near zero from the green wire to frame/battery ground.

[Suzukidave]

My best guess is a voltage leak somewhere. Kill switch 'off' key on and off, the lamp stays lit, BUT gradually dims. In 3 or 4 minutes you can barely see it. I don't know that it ever goes completely out as I haven't waited to see.

You really should figure out this problem

[Coyote]

The orange horn wire has 12V with the key on and zero when it's off. That side seems to be OK. The green on the other hand seems to be open. I checked green to ground and the button has no effect at all. According to the schematic, the green wire originates at the switch. There is no change in ohms between the green wire and ground with the button depressed or not. Both ways are 100% open.
I thought I was missing a ground somewhere So I rigged it all up with jumpers yesterday and tried all different kinds of stuff with no results. I remember when I built RedZone, I had to run a wire from the switch (pinched in the clam shell halves) to ground to make the horn work, but I though that was because the bars were painted. That is not the case here, but I tried it anyway. No joy.
This all points to the switch itself. (I think). But I can't seem to convince myself. Everything else works fine on the switch. Turn signals, lights on and off, hi/lo beam. Never the less, I am going to open the switch again and have a look. At least check continuity between the green wire in the switch and the green wire at the horn. I know the horn works because I have jumpered it directly to the battery +/- and it works, though the tone and decibels suck. I have a much louder automotive type horn I am going to replace to replace this POS with, but not till I can make it work.
I can't believe I am having all this trouble. Everything on the bike worked when I got it. There was no headlight and no turn signals so they weren't checked, however they both work. I only changed 2 things. I replaced the fuse to a modern blade type and I replaced the left hand switch to one off a 75 so I would have the light on/ off function. Oklahoma law requires the headlight to be on but it's nothing like enforced - at least in Tulsa. The master cylinder is aftermarket and the front brake has a microswitch instead of that lousy OEM slider. Works great!

[yeadon_m]

I think the horn button works by making continuity to ground when pressed. There's a spring loaded plunger pin and IIRC that goes to ground via the handlebars when pressed. It'll all be clear when you split the switch case, that bit isn't complicated.
Cheers,
Mike

[Suzukidave]

I checked green to ground and the button has no effect at all. According to the schematic, the green wire originates at the switch. There is no change in ohms between the green wire and ground with the button depressed or not. !

Diagram shows the green going back to the button like you say and the other wire coming out of the switch a b/w and thats ground . So yep pushing the button completes the circuit to ground .

[tz375]

At the risk of restating what has already been said, the horn circuit is:

Orange (12v switched power) -> horn
Green (ground) horn -> switch
Green is grounded by button.

The question appears to be are the two leads to the horn spliced correctly into the harness and is the horn button grounding properly.

[Alan H]

Right here we go.
1.Turn on the ignition. (This puts 12v to the orange wire.)
2.There should be 12v to the horn on the orange wire. Earth the green wire from the horn.
3.Does it sound?
4.Yes, the horn is OK, no the horn is u/s - mend it!!
5.We assume yes, so then the green wire goes to the multiplug in the headlamp. Earth the green pin.
6.See 3 above. No the green wire is duff. Yes, carry on.
7.There should be a black and white wire from the horn button.
8.Make sure it's earthed into the loom and press the horn button
9. see 3 above.
10.if it works it's the earth to the loom that has a break in it or the loom isn't earthed via the black & white wires. If it doesn't the break is between the button and the end of the first earth wire from the button.

Note that the button does not earth inside the bar switch assembly, the earth path is on the black and white wire from the multiplug.
ALL black and white wires should be connected to the loom which should be earthed in various places around the bike - in the headlamp (on the headlamp ears where the indicators fit), and near the battery.

[yeadon_m]

No wonder some of us call it Elec Trickery!

Thanks Alan, as usual, I've learned something.
Mike

[tz375]

Guys, are we sure that the 550 has a black and white ground wire in that switch? I just checked a GT750 left switch (early style) and there is no ground wire. It grounds through the switch body to the bars and from there through the steeringhead bearings to the frame. There is no ground lead in the switches I examined.

[Suzukidave]

That strange Richard as the diagram shows one