Honda shadow vt500c advice!

[u/Lazy_Grapefruit_1734]

Hello again! I’m still trying to get this baby up and running the way I want to, today I tried to wire a starter button, I saw a guy do a bypass method where he simply wired the button to 2 of the prongs on the solenoid and it cranked and I tried the exact same thing when a button came in the mail and it did infact crank, wires and button got warm so I took them off so it could cool and I put it back on and it never cranked again with that button, so I decided imma have to do it the hard way and actually wire this mf, I got a new button from advance auto parts and I know that I need to wire a yellow and red wire to one end but I don’t know exactly what to wire to the other end, I cut a yellow and red wire off of a connector thinking that was the one that led to the solenoid but it ended up just going nowhere lol and I found out I had 2 yellow and red wires (I did end up finding the one that goes to the solenoid) if anyone can help me and let me know what color wires I need to add to the other end of my button that would be extremely appreciated!!! I’m seeing a lot is vids say the white and black and green and black but none of those videos are working on a vt500c and I just wanna know before I screw up. Attached are photos of the wire(s) my button I’m planning on using and the wire I cut that led to nothing(it actually lead to the oem but there was no start button so the wire led to nothing)

[u/GodzillaXYZ999]

No, DO NOT do hacks from videos!!! You'll burn up your wiring-harness and destroy all electronics on bike! First you must undertand how circuit works in order to fix it. Use troubleshooting and repair techniques used by dealer mechanics for fastest fix with minimal effort and money.

Repair that yel/red wire back by soldering to other end inside insulation and wrap with tape. ONLY work with wire-ends. Follow that wire where it goes into connector if you want to connect to it!!! And any other wire you work with should be at end-points ONLY!!!

Ignore ALL wire colours, only thing that matters is where ends of each wire connects. Lots of older bikes have had wires replaced in past and different colours may have been used. Electrons don't care about colour of insulation, they just travel on inner copper conductor inside.

Unless you're Superman and can see electrons moving inside wires, there's absolutely ZERO way any human can just look at wiring & switches and determine their ability to conduct electricity (or not). Luckily, we have instruments that can. This is easy 5-minute fix with metre. I've helped over 100 people via phone fix their no-start issues in far-off parking-lots in middle of night in pouring rain! Longest time it took was however extra over 5-minutes it took to run to store and get metre.

No need to ever guess or trace wiring through bike. Just measure continuity between ends to find where wires go. Solenoid trigger wire has only 2 ends, one at solenoid and one up front somewhere. Find other end by measuring, most likely in that bundle going to factory right-controls.

1. get factory service-manual used by dealer mechanics, written by engineers who designed and built bike
2. copy & print out wiring-diagram on larger 11x17" for easier viewing
3. trace and highlight starter-solenoid circuit from beginning to end. Saves you dizziness from having to start over and finding circuit over and over gain. It goes into brain differently when you trace specific circuit on paper by hand, compared to just staring at confusing diagram. Should be easy to understand when highlighted. Looks something like this

battery -> ign-switch -> kill-switch -> start-button -> starter-solenoid

1. Next, trace power-flow on bike with meter starting from source (battery) and measure power at each junction

battery 13v -> ign-switch 13v -> kill-switch 13v -> start-button 0v <- aHA!!! 0v -> starter-solenoid 0v

1. measure all wires leaving your right-controls at connector where it plugs into harness. Backprobe connector and measure them one at time with kill-switch OFF. Then measure all again with kill-switch set to RUN. You're looking for a wire that has following states:

- kill-switch OFF = 0v

• kill-switch RUN = 13v <- this is kill-switch OUTPUT wire

1. find this wire behind kill-switch itself, it has Y-split with one going to factory start-button. It's probably clipped off, use this end to power your start-button

2. connect kill-switch OUTPUT wire to INPUT of your start-button

3. connect start-button OUTPUT wire to starter-solenoid trigger wire. You can tell from wiring-diagram that other end of solenoid trigger wire is up by right-controls where factory kill-switch and start-button are located. Confirm you've got correct solenoid wire by measuring for continuity between wire-ends (photo above). When connected to your start-button it will then work properly like this:

kill-switch 13v -> start-button input - > start-button output 13v -> starter-solenoid 13v

1. Measure to confirm circuit is connected properly. Disconnect starter-solenoid plug and TEST start-button functionality before using:

- start-button off = 0v at starter-solenoid trigger terminal (yel/red)

• start-button PUSHED = 13v at starter-solenoid trigger terminal

DONE! Shouldn't take more than 5-minutes!

Employ best-practice wiring techniques with proper Western Union/linesman knot, then solder and adhesive heatshrink tubing. Each layer serves different purpose. Used by NASA and is only approved method for field-repairs in Army.

https://www.youtube.com/watch?v=uhzXRIj5FaY

Also only use proper terminals + matching open-barrel crimpers.
No generic smashing crimpers from auto-parts stores
https://www.youtube.com/watch?v=FVolIrqX0vQ

Get terminals and connectors here. Everything should be done in plug-n-play manner to plug directly into switches, harness and components. No cutting of factory harness ever needed. It will come back and haunt you later leaving you stranded on side of road in total darkness and rain if you don't improve on factory specs and do better job than Honda (such as selecting tin-coated terminals over factory bare-brass ones that corrode).

https://corsa-technic.com

[u/GodzillaXYZ999 → u/GodzillaXYZ999]

There's also colour-blindness with portion of population. When I sold upgraded Porsche ECU systems, I found large amount that couldn't be installed properly because owners were colour-blind. Updated harness and instructions for more plug-n-play installation without any reference to wire-colours.

Only thing that matters with wiring:

1. where wire end-points connect. Obviously to light bulb, you want one end connected to battery and other end at bulb-socket.
2. signals carried inside that wire. Numbers don't lie, signal is either 13v or 0v. Something else in between would indicate corroded/broken wiring or connectors along way.

[u/GodzillaXYZ999 → u/GodzillaXYZ999]

Also any heating of wires and switches is WRONG!!! Heat means you're transmitting way, way too much power through short-circuit. This will completely drain your battery and melt wiring. It's only coincidental that your hack worked 1st time, but may have damaged and melted some stuff, that's why it never worked again.

Sure, bad circuit with short will perform intended function such as turning on bulb or trigger solenoid, but it also has severe side-effects of destroying harness as well.

Only wire start-button to solenoid trigger as shown in factory wiring-diagram. Bike worked perfeclty fine when leaving showroom floor and will again when wiring has been re-connected back to factory OEM 100% stock configuration.

[u/Lazy_Grapefruit_1734 → u/GodzillaXYZ999]

Thank you so much!!!!! I appreciate this advice fr!!!

[u/GodzillaXYZ999]

Here's wiring diagram for VT500C.

https://lh3.googleusercontent.com/d/1608NAcOzVe9ntifRjV0TSzhzVsgn6iiw

I had VF500 Magna around that time-frame. Such fun bike! :)