My GS450 Wiring Diagram (Thinking about making a custom Harness)

[sam000lee]

I'm trying to milk the last couple cold weeks by giving my GS450 another makeover. My harness is fairly altered including butchering from PO's mechanic and some changes I've made (coil relay, SPG) and so I thought it would be a good project to make a harness from scratch. I want to do away with the stock gear indicator/idiot lights and make my own slim version with some LED's I got on ebay along with a little voltmeter.

First step is the wiring diagram. I did away with some of the redundant circuits in the stock set up and want to minimize the headlight bucket nest. I tried to lay everything out to match where they would be on the bike. This diagram includes an Single Point Ground (SPG), Coil Relay Mod (CRM) and I'm using an SH775 R/R. I have a tray under the seat that all my electrical bits (battery is in stock position) are going in.
Some comments:

- For a fusebox I am thinking about using using this Powerwerx 6 Circuit Fusebox to have separate fused circuits to different systems
- I would add color after doing the actual wiring to make for easy future reading or at least label the colors (esp. stock wire colors coming out of each component)
- Horn and Aux light havn't been "wired in" to the diagram yet. Neither has the Oil and Turn signal indicator lights and voltmeter on the dash (all pretty straight forward just didn't get to it last night before snapping the pictures)
- I'll be using stock handlebar switches which allows me to have the extra hot wire coming out of the headlight On/Off switch to power the tach/speedo lights.
- The stock set up has the battery wired to the Starter Relay and the ignition and all hot wires coming off of the same terminal on the Starter Relay - Would you recommend I keep this set up or does it make any difference just having another wire from the battery going to the fusebox. Didn't draw some of that in yet including the output from the R/R.

 

[posplayr]

It is difficult to read as none of the wires have any marking, but your R/R(+) seems to be grounded to the SPG.

 

[sam000lee]

Right - none of the wires have labels/colors yet and their orientation with respect to different components isn't based on the physical layout of what those components look like.

The wire going from R/R to SPG is supposed to be the ground wire (sorry that's a little confusing) and, like I said in the original post, I purposely haven't drawn in the R/R (+) and am asking for recommendations whether it should meet the Battery (+) wire at the Starter Relay (similar to stock) or if it would be better to go directly to the battery (or someplace else, or if it doesn't matter).

 

[posplayr]

Right - none of the wires have labels/colors yet and their orientation with respect to different components isn't based on the physical layout of what those components look like.

The wire going from R/R to SPG is supposed to be the ground wire (sorry that's a little confusing) and, like I said in the original post, I purposely haven't drawn in the R/R (+) and am asking for recommendations whether it should meet the Battery (+) wire at the Starter Relay (similar to stock) or if it would be better to go directly to the battery (or someplace else, or if it doesn't matter).

The OEM configuration is best from a safety and voltage regulation perspective. If you think about what the SPG is really doing in terms of collecting currents to return them to the R/R)(-), then the R/R(+) is the opposite situation for distributing those same currents.
Keep in mind there needs to be a fuse as close to the battery as possible for feeding the R/R(+).

 

[sam000lee]

Thanks Pospalyr - glad to have your input. Still need to work on the diagram a little more.

 

[sam000lee]

I'll be using this OE - Style wiring from Dime City Cycles for most parts of the harness. I asked their customer support and it's supposedly "Around 18 gauge". I think it's fine for most wires and they have it in a bunch of color combos.

Obviously, I'll use something heavy for the Battery(+) to the starter and to the ignition/fusebox, as well as the battery (-) to the SPG. I have the Triumph Connector for my R/R which has heavier wire so that covered too. Anything else I should use larger gauge wire for?

Any other tips from anybody who has made a complete harness before? I think I'll try to take a bunch of pictures and maybe make a little write up.

I plan on laying everything out on the bike with zip ties before applying any kind of wrap or crimping connectors in. Unfortunately, I crushed my multimeter putting the bike on the centerstand a while ago so I need to get a new one of those...

 

[posplayr]

I don't know if you saw this, you can compare all of the wire routings in it to your schematic. There is even a Powerpoint file that you can edit to change the wire colors depending upon what you end up using.

http://www.thegsresources.com/_foru...mal-550-Bobber-Schematic&highlight=550+bobber

 

[sam000lee]

I ordered a whole bunch of different colored wire and am going to get started on this over the weekend. Any recommendations for fuses coming from the fusebox? It's rated at 25A and I'll have a 15A on the Battery(+) wire which is stock.

This is part isn't in the drawing above but I'm keeping the starter motor/main power set up in the stock configuration which is one Battery(+) wire going to one of the Starter Solenoid posts with a 15A fuse. Also on this post is the R/R(+) and the wire leading to ignition switch and then the fusebox.

Looking for suggestions on what to put in the fusebox for:

Fuse 1: Powering coils and ignitor unit.
Fuse 2: Headlight/taillight (I need to change the taillight wiring in the diagram a little for anybody who caught that), clock lights and dashboard LED's (there are 10 mini LED's).
Fuse 3: Turn Signals
Fuse 4: Horn - Are there any pros/cons for this having it's own fused power coming from the fusebox? I thought it might be a good idea since it might get a little extra juice not sharing current from other components.
Fuse 5: Aux. light (Also not drawn in yet but this will be switched).

 

[Gorminrider]

You have an unfused wire from +Bat to "coil relay". That's odd.

Really, it might help to have a look at the 4 cyl bike wiring diagrams, which have independent circuit fusing. These have a 15 amp Master fuse devolving to 10 amp circuits. and That should give you a good idea as to fuse values...

I Note that in OEM diagrams, the fuse is always the "last" thing the current passes through on the way to +Bat...so , having a switch "after" it is a bit odd. Note that Suzuki doesn't run the +Bat through the key switch that way. But then, with all that wire going up to the handlebars and back they wouldn't, would they.. still, I'd put the before the fuse.

Note that my "last" seems a little contrary to common sense per Positive voltage, but actually, electrons flow "FROM" negative.... electrons ARE " -". It's an aside but it can be a good exercise to imagine your diagram the electron way, "flowing" from the negative pole.

If your horn is extra power, sure, give it it's own circuit. 10 amp fuse is max for aux. but I always like the smaller I could get away with ie: if you use LED aux lights or want to plug in the cigarette lighter accessories. Fast Blow fuses might be something to consider here given digital doofunnies but that's just a guess.

 

[sam000lee]

Thanks - I've had the CRM for a while and do have a fuse between the battery(+) that I hadn't drawn in. I'm probably going to just route it through the fusebox.

I got started on this over the weekend and obviously underestimated how long it would take. I had bought a bunch of different color wire but am going to return pretty much all of it after I took apart the old harness - pretty much all of the existing wire is in great shape and I'm pretty sure I'll be able to preserve all of the original color schemes for the different components. Plus it lets me keep things like the headlight plug and wires attached without having to cut and splice in new wire. Here's how nice it looked under the old/stiff/dirty harness wrap:

I welded a little plate to the battery tray to mount the starter relay and was able to use the battery box mounting post for my coil relay. I'm zip tying a lot of the wires into place for now before putting it all in a loom. Another benefit from re-using wire from the stock harness is that there are a lot of 1 -> 2 and 1-> 3 splices that make routing power to multiple places easy. You can see it here there's a 1-> 3 orange wire I'm using to take power from the coil relay to each coil and to the Ignitor unit.

New connector from vintage connections:

Do you think it's alright to mount the R/R with the fins going perpendicularly to the length of the bike? It makes everything fit in my tray a little better but I don't want to compromise the cooling of the unit. These run pretty cool right?
(Also a picture of my SPG mounting point)

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I'm making a new dashboard and was going to use LED's for everything but now am thinking I'm going to reuse the bulb assembly and number plate. I was very happy to cut off that connector which has been the culprit of my gear indicator lights vibrating on/off:

 

[sam000lee]

My old harness at the end of Sunday:

 

[Gorminrider]

Do you t

hink it's alright to mount the R/R with the fins going perpendicularly to the length of the bike? It makes everything fit in my tray a little better but I don't want to compromise the cooling of the unit. These run pretty cool right?

perpendicular should be fine but I don't think I'd ever put one "under the seat". ...it seems like one of the most sheltered places from airflow on the bike and seems to explain why stock airbox takes air from here...
I always hate where the stock R/R is on these and this bulkyHonda SH232 R/R gave me an excuse to mount it outside... By the way- Good for you! you are goin' for it! getting into this project!

umm. also as an idea maybe you can bolt to underside the battery box . My 650 does this. I can't remember if I looked at this option for my 81' 400E ..might have found wirelengths to be an issue or similar....

View attachment 50244

 

[posplayr]

Glad sanity prevailed. As you have now realized there is a whole lot of work that goes into a harness. As you have found generally the wire itself is not the issue, it is much more often connectors and exposed wires. All connectors can be changed and with a donor harness you have a source for a all of the OEM wire. The main thing you want to do is make the changes related to the charging system. This was the weakest area of teh old harnesses/electrcial systems.

 

[sam000lee]

Got some more work done this weekend. The ignition and starter systems are all set and so is my charging system once I put a fuse between the R/R(+) and battery.

As you have now realized there is a whole lot of work that goes into a harness. As you have found generally the wire itself is not the issue, it is much more often connectors and exposed wires.

Definitely true. I actually have a couple of GS450 harnesses that I've been pillaging and the only new wire I have used was some thicker gauge stuff for the battery ground and starter connections. I bought a bunch of new wire but will be returning it.

Here's me laying out the lighting system, there are some numbers that are a little hard to read. Re-using old harness wire was SO helpful here because all the splices already match. For example with the high beam wire - it goes from the handlebar switch to a 2-1 (3 way) splice to send to both the headlight AND the HB indicator lamp in the dashboard. The lengths were just right (did end up trimming) but it saved a lot of time AND I don't have and haven't seen a good source to get the splice crimps that they use (or equivalent)

1. Are the High beam and turn signal indicator wire
2. Headlight and front turn signals
3. Left handlebar switch
4. Horn
5. Power from fusebox
6. Rear light and turn signals

Matching left control unit to my harness. I cut out the W/R W/G wires that the stator -> R/R used to run through to slim a little:

Some of my crimps to go in a vintage connections terminal block:

Everything zip tied on - I'm using LOTS of zip ties:

I was playing with the idea of routing some wiring through my handlebars (From a CB350). It definitely works with the now 9 wires if I shorten my grips a little but I'm also thinking about putting those bars on my GS750 since the bars I got for it feel a little too low

This week I'm going to clean up my old PVC loom(s) to get the goo off and try to soften it up a little as well as crimp up the left handlebar wires.

I still need to wire in the brake light switches, measure all the wires like 5 more times before doing final trimming and crimping. Test and then put the final loom on and wrap.
Does anybody have a good source for the non adhesive wiring tape?

Lastly I need to do my dashboard still but I'm putting that on the backburner until I've finished with everything else. I took off work 4/13 and 4/15 and have the following monday off to go on a camping trip to upstate NY/VT.

 

[sam000lee]

More crimping. Took the wire sleeving for the hand controls from my junk GS450 it's a little nicer. Also cleaned up the old PVC loom.

Still looking for suggestions on non adhesive loom tape.

 

[posplayr]

I would spray all that shiny brass with DeOxit or smear dielectric grease.

 

[sam000lee]

I would spray all that shiny brass with DeOxit or smear dielectric grease.

Will do - up until now I've been buying those little sugar pack type things of dialectric grease they usually have at the counter of Autozone or equivalent for quick wiring clean ups. Maybe it's time for me to just get a proper tube now.

 

[posplayr]

Will do - up until now I've been buying those little sugar pack type things of dialectric grease they usually have at the counter of Autozone or equivalent for quick wiring clean ups. Maybe it's time for me to just get a proper tube now.

The DeOxit will flow into the crimps, someplace the grease can't get into. It is not permanent, but will significantly increase the longevity of the contacts.

 

[sam000lee]

Okay so I'm going to try to finish this up this weekend since I'm supposed to go moto camping next weekend. I have some questions about where to put fuses mostly because I had `In line' fuses between my coil relay and bat(+) as well as my R/R and Batt(+) and would like to just use the fusebox to clean up some of the mess. I drew up this quick diagram just putting the previously In line fuses into the fusebox (Note that "Starter" should be "Starter Relay")

Questions:
1. My fusebox is rated for 25A max and the 15A fuses for Coil Relay and R/R already are over that. Should I just run the seperate In Line fuses and wire them to the starter relay post (labeled A in the diagram) to get battery (+) power or is the configuration in the diagram OK?

2. I was going to run the wire going to the starter button and the wire going to the Kill switch from the "Lights" fuse but thought since I have the space on the fusebox I might as well just give them seperate fuses. Would I be okay with a 2A fuse (where the blue line goes into the fusebox)? I would think that these don't draw much current since they're just the "Switch" wires.

3. Does anybody know how many Amps the horn draws?

Thanks

 

[tom203]

Moto camping next weekend?....I hope you're going south or west! I still got 1 foot plus in my yard.
Anyways, the starter relay draws 3 to 4 amps, so use a 10 amp fuse. Never measured a suzuki horn, but it's likely in 5 amp range.