Turn Signals Working

With the switch mounted and a new electronic, universal motorcycle flasher installed (the one I bought previously was mechanical and failed to work properly) I was ready to wire up the new signals. I mounted the front signals to the sides of the headlight can, as they are on Honda CBs. For the rears I made two brackets (one for each side) that I screwed to existing threaded inserts I found on the frame, and mounted the signals to these brackets. Note that I had some initial problems getting the signals to work due to insufficient grounding. The signals have case grounds, so I used ring terminals attached to the turn signal post mountings to ground all signals to a good ground (there was an available green wire under the seat and one in the headlamp can). Here is a short video of the working signals:

Turn Signal Switch Install

With my modified turn signal switch in hand, I set out to install it on the bike. The first thing to do was to remove the old horn-only switch. I unhooked the wires from within the headlight housing, disassembled the switch housing and tried to pull the wires out from inside the handlebars. They were in there fairly snug. Unfortunately I ended up tearing the wires off of the original horn switch, but I got them out. To facilitate installation of the new switch, I had attached a piece of string to the old wires before pulling them out of the bars. I now had a string running through the handlebars, along what would be the route of the new wires.

Well, that all sounds great. But there was a problem. The old hole, to get wires into the handlebars from the switch, was too small. The new switch has more wires and requires a larger hole. How was I going to drill out the hole without loosing the end of the string running through the bars?

Well, I decided to push the string just inside the bars and then drill the hole. I was hoping that I'd be able to fish it back out somehow. The string ended up slipping too far into the bars and I was unable to see or reach it after drilling. The solution I came up with was to use air to blow the string back towards the hole. I don't have an air compressor, so I used that canned air you use to clean out electronics. It worked great!

The switch housing had a pin in it which protruded towards the bars, presumably to make sure the housing is properly oriented on the bars. Since my bars lacked a receiving hole for this pin, I just cut it off and ground it down flat.

After much wresting and a bit of re-soldiering, after I tore a wire loose from the switch, I got the new switch wires run and the housing mounted. Unfortunately it is not perfect. I cannot get the housing to close all of the way. I don't have a good picture of it, but there is about a 1/8th inch gap between the upper and lower parts of the housing. The wires internally are keeping it from closing. I'm not sure what to do about it, perhaps I started from the wrong switch. But for now it is installed sort of. Fitting the new switch was by far the hardest part of adding turn signals to the bike.

Modding the Switch

As I mentioned in a previous post, the original, optional, turn signal switch for this bike is nearly impossible to find (unless you are willing to spend exorbitant amounts of money for it). Sources a reasonable replacement, from another vintage Honda, is a problem also because they all seem to have one of two issues:

1. They have a headlight hi-low switch on them. On the SL350 that function is already controlled from the other (right) handlebar switch.

2. They have the base of the clutch lever, and rear-view mirror mount, cast integral to the switch. On the SL350, there is a separate bracket for the clutch and mirror.

So, I bought a switch (aftermarket part, like the vintage Honda switches but not for a specific model) that had the clutch and mirror mounts, and decided to try and modify it to resemble the original. Here is a picture of the part before I started (the protrusion on top is where the clutch and mirror mount):

I began by cutting off the bulk of the mount with a sawsall:

Next I used a rotary grinder to further shape this area. And then I sanded the results of that.

 

Lastly I painted it, and then I was ready to go, or so I thought.

Turn Signals

Well, so I've been contemplating adding turn signals to the bike for some time now. I just think it would be safer. I mean, you can use hand signals and all, but not always when you want. The signal hand is also the clutch hand. Plus, I've been getting mixed messages about whether or not they are required by law in Washington. Some say that the bike is grandfathered in, due to its age (it didn't have signals when new, it doesn't require them now). Some say that the Washington turn signal laws don't apply to motorcycles. And a lot of web sites list Washington as a state that doesn't require them. But the RCW that applies to turn-signals seems to suggest otherwise:

http://apps.leg.wa.gov/rcw/default.aspx?cite=46.37.070

So anyway, Ive started the process of trying to retrofit the SL350 with turn signals. Apparently these were optional items when new, though I think few had them. The parts for the SL350 specifically, like the handlebar switch, are nearly impossible to find. But there are available substitutes from other vintage hondas. Here is a little video of some initial testing of some of the parts I've acquired.