[JohnMacDonald]

Hello Everyone,

So I have been working on my '78 Twinstar for the majority of the summer and have gotten everything running perfectly and have finally comes face to face with the electrical issues that I have been avoiding. The bike sat for about 15 years before I got it, but it seems all of the wiring is good except for these 2 wires. It is a green wire and a light purple wire just hanging inside the headlight. I have looked and can't seem to find any spot where they are supposed to go. The horn / speedometer / cluster lights (except for the neutral light) / all of the blinkers do not work. I have no experience with electrical issues which is why I am hesitant to just go dive in and would rather get advice from others before I mess something up. If anyone could give me some insight on the next steps I should take or what I should look for, I would really appreciate it. Everything else works good. It fires right up, headlight / brake light work fine / no other issues. Thank you in advance for any help.

John

​

 

[Day444rider]

Green wire is a ground. Brown and white wire is for the speedo light. Light Purple wire?? Doesn't show on the diagram I have.

Turn signal lights are a black wire, right has a blue marker, left has a orange marker towards the connection for the wire harness plug. Both have ground wires as well, should be green and attach to the head light mounting bolts on the inside of the headlight.
High beam indicator: a green and a dark blue wire. Turn signal indicator: a light blue wire and an orange wire. Neutral indicator: a black wire and a red/green stripped wire. Speedometer light: a brown/ white stripped wire and a dark green wire. Head light: green on the right, white in the center, blue on the left. with the headlight pointing straight ahead. Horn: a black wire and a light green wire. A bunch more connections fit inside the headlight. Wires from both hand controls, front brake light switch, horn switch. Yeah it can be a mess. One wire at a time...

Start from scratch. Remove all the wires from the connection plugs. Rewire (using the existing wires) one component at a time.

 

[longdistancerider]

You need the wiring diagram to sort this out, it's in the FSM. PM sent about that
There's a "scotch-loc" I see in there on a Brown w/White wire. There should never be those anywhere on the wiring harness, someone was trying to fix something by shortcut instead of an actual repair.
+1 on disconnecting everything and starting over.

 

[Day444rider]

You can find a color diagram in the "Clymer Honda Twinstar 1978-1980" repair manual. Can't hurt to have one on hand. Honda shop manual is not in color, but if you can read simple wiring diagrams it's a big help.

Wouldn't happen to live in lower New York? If so I'll offer you a hand...

 

[Day444rider]

Ok, let's say you've redone the wiring and things still don't work as they should. You can take the left hand control apart, clean and lube it with some dielectric grease. Couple words of caution it contains some fairly small screws and a spring for the horn button; the solder joints are not the strongest use care moving the wires inside the control. Take some cell phone pictures as you take it apart step by step. You can use use some small plastic shims if they are needed. (I used a coffee can plastic lid, cut as needed.) -Turn switch was loose.-

 

[JohnMacDonald]

Ok, let's say you've redone the wiring and things still don't work as they should. You can take the left hand control apart, clean and lube it with some dielectric grease. Couple words of caution it contains some fairly small screws and a spring for the horn button; the solder joints are not the strongest use care moving the wires inside the control. Take some cell phone pictures as you take it apart step by step. You can use use some small plastic shims if they are needed. (I used a coffee can plastic lid, cut as needed.) -Turn switch was loose.-

Thank you very much for being willing to help! I am going to dig in to it right now and see where I end up. I don't really have any electrical expirrience so I'm going to not try to re-run all the wires just yet but if worst comes to worst, I will give it a shot. Unfortunately I am in Michigan so it'd be a bit of a hike (especially on a Twinstar lol). I'll keep you posted on what I come up with. If you wanna shoot me a text or something, it might helpful to have you available if I have a question. My number is 616-510-7246. If not, that's cool too. Thanks!

 

[Day444rider]

Hey there John. You really don't need "electrical skills" to do the re-routeing of the wires. Some spare time and some deep breaths will get the job done. If you get hung up along the way, just post the problem here. (That way it's shared with anyone else who might have the same or similar problem.) I'd suggest editing out your phone number in your post, just to be on the safe side.

 

[enb54]

Hi all...
Just a quick information note...
I just finished helping a friend with a 1978 CM185T and an aggravating turn signal problem, so thought I'd add to this thread. We found several grounds were not quite up to snuff so cleaned them, then found that we were losing about 1 volt through the positive side of the electrical wiring to the flasher relay and no amount of cleaning connections seemed to make it any better. After trying an aftermarket and an original Honda 6 Volt flasher from my machine with negative results we installed a CEC EF32SS-R solid state flasher and success! The tail light still dims slightly as the turn signals flash, so more connection cleaning is in order, but installing the EF32SS-R flasher relay was key to getting things going...