Wiring Confusion

[jmcgill89]

I had to take all the wiring apart behind the headlight on my '74 GT550 in order to get the cluster off so that I could work on the gauges.

Upon putting it back together, I don't know where to put the right side wire for the front turn signal. The left side's black wire just plugged into the black wire that had a connector on it. The right side's wire has no corresponding black wire to plug into.

Also, there are two wires in there, a light green one, and a brown one that have nothing to plug into (they're both female ends). I was looking at a wiring diagram, and it shows the right turn signal maybe plugging into the green one, but when I do this, I get nothing from that front signal (and it worked prior to disassembly).

Can anyone tell me what these wires are?

Thanks,

Joe

[H2RICK]

Joe, the light green wire is for the right hand signal.
Suzuki used BLACK insulated wire for ALL the signal wiring ON the signal itself to make things easier for manufacturing.....and to save a few bucks. IIRC, they quit using differently coloured signal wires about 1972 or so.
They used to put a small sleeve of light green plastic on the signals that are intended to go on the right side of the bike but your small sleeve has probably rotted off over the years.

The spare BROWN wire is PROBABLY for the "city light" built into the headlight of the Euro-spec bikes.

[jmcgill89]

I guess I've got a burned out light then....or something similar.

The back signal works and comes on, but the front one does not.

[Suzsmokeyallan]

Yes Rick, on Suzuki a brown positive feed wire and a black ground is the supply for the 'parking lamp' or 'city lamp' fitted into the HL reflector for certain markets.
The wiring codes never change, even today the Bandit for example uses the same wire colour patterns and has the connector there for the parking lamp in the harness.
Joe, check your ground, your bulb, and positive feed wire for that indicator to confirm where the issue is. Let us know how you make out on this.

[jmcgill89]

I'm in the process of putting it all back together now. I had the whole front end off because I had to replace the headlight ears.

Once I get the wires sorted out, I'm going to have to take the carbs off and replace the float valve in the middle one...it was stuck and the carb was leaking big time.

After that I'm taking out the baffles and cleaning the mufflers up...I've got tons of oil in there that is smoking big time.

[Suzsmokeyallan]

Ok sounds like you have a bit of work ahead, how do you plan to clean the baffles of the old oil.
I take it you are removing the pipes to wash them out as well because if they are really oily they will just re-clog your nice clean baffles.

[jmcgill89]

I'm fairly certain it is the signal itself. I plugged the black wire from the left side signal into the green wire, and it worked along with the right rear turn signal.

I took the right front signal apart, but got nothing out of the ordinary....it looked fine.

I just repainted the ears, do you think that's interfering with the ground for the signal?

[tz375]

Each headlamp ear has a ground lead attached to the bolt. Did you fit those?

[jmcgill89]

My signals only have one wire coming from them, and the nuts holding them onto the ears were just that, nuts.

The nuts that hold on the headlight to the ears have grounds.

[Suzsmokeyallan]

Are you referring to a threaded square holed alloy nut piece with the wire attached to it? got pics??

[jmcgill89]

I'll have to take pics tonight, but yes...my headlight bucket is held to the ears via the square threaded nut with the wire attached to it. The signals are held onto the ears just with a standard nut with a lock washer.

[Suzsmokeyallan]

I often wondered about those and why some bikes had it done that way. Usually its a flat washer against the indicator shaft rebate then it goes through ear and the square nut and then it has a nut and a lock washer on the inside of the bucket.
Suzuki made two types of those square nuts, one without threads and one with threads.
I prefer to have it with the hex nut inside the bowl since on the outside you only see the shaft and a flat washer against the ear.

[jmcgill89]

Well, it's now fixed.

Apparently, I didn't have the nut securing the headlight to the fork ears tight enough...once I tightened that, the signal had its ground and all was right with the signal.

Thanks!

[H2RICK]

Another fine example of Uncle H2's electrical troubleshooting axiom:

90% (give or take) of electrical problems involve bad/dodgy grounds.

It's funny how it works out like that......

Glad you've got it sorted out, Joe.

[jmcgill89]

Yeah, me too!

Now I get to start on replacing the old starter clutch....which kinda stinks, because I just got it registered and all....I was hoping to ride immediately, but I gotta get that old, messed up starter clutch out of there first and foremost....that rattling is a disconcerting sign.