gpz550 ignition switch

Check your fuses too.

Update

I made it home safely after 3 failed attempts at bump starting, I was able to get the ignition switch to work without the headlight.

For starters I was in downtown LA, at an intersection with a lot of foot traffic. The first attempt i had to stop for a jay walker. 2nd attempt, i guess my seat wasn't all the way locked down, so when i threw my leg over I kicked open the seat. how i didn't drop it after that surprised me. The 3rd attempt I forgot the turn my ignition switch on... I was turning it off between attempts to preserve battery. And of course this was all right after i got a 93$ parking ticket... Here is a picture of how I was parked, right at the red, to give the car some space to leave.



for the MOST part, it ran fine after the bump start. Every now and then I would loose throttle response and receive a very loud backfire and the only was to get power back was to clutch all the way in and give a little throttle. This happened about three times on my way home. I was about a 40 minutes ride away from home and 30 minutes until the sun went down. luckily lane splitting is legal.

Life is but a shipwreck of our plans

Any advice? I rebuilt my starter last July, brushes and I emory clothed the armature and commutator brass parts.
When i first got back to my bike It turned on normally, then i put my helmet on then looked back and it was off. ignition works with headlight unplugged, and starter not getting the power it needs i guess.

Sorry this may be a obvious statement but it sounds like you have a corroded connection... It sounds like it will carry voltage but breaks down under load... The loss of throttle is likely due to low voltage at the coil primary... Sorry I cant help more but its time to start looking at every connection for corrosion

Every gpz550, and basically every 30+ year-old bike for that matter, I have worked on had wires failing in the harness between the frame and steering area. By failing, I mean actually breaking due to repeated flexing. I just rewire from scratch on most bikes. That is not a fun task even if you've re-wired dozens of bikes.

Because of your ignition switch problems, that is of course a main suspect. But since you've been working in that area, it's also possible you've disturbed some harness wires nearby that were marginal to begin with.

I would suggest a temporary jumper that you keep on the bike as a secondary ignition switch. It should have a switch in the jumper so you can just open the seat and flip the switch to keep running. Then as the problem gets worse, or becomes permanent, you can troubleshoot it properly with a voltmeter. You won't get stranded since you will have the emergency jumper.

If you're interested I can look at the diagram and suggest a convenient place to tie in the jumper.

For parking tickets, always carry a can of gray spray paint to paint over red or yellow curbs.

does anyone know the cross compatibility for the 81 gpz harness?

I think there might be an KZ550-A2 one on partzilla. here's a side by side with some of the differences I see, not quite sure what the extra connections are for



also found a new wiring harness made for the z400fx, another similar bike.

Making my own harness might be way out of my skill range, might end in a disaster, but that is probably the best option. Might even have to get someone to make me one, don't know where I'd find that person lol
My 81 Honda c70 needs a new wiring harness, maybe I should get some practice there

So my search for finding someone to make a wire harness is coming to an end, and its looking like I will have to make my own harness.

Most places that manufacture harnesses only make them in larger quantities, Curious if I got about 10-20 made would there be a market for them here? I guess I would be the only market for this one off wiring harness at that point.

So as far as making my own harness, What gauge wire should I use? and are the stock connectors able to be reused? just need some tips and pointers in general, would be my first time attempting something like this.

Thanks in advance.

Hello, it's been a minute

So I took the route of making my own wire harness, came out pretty decently I would like to say. Used 18 gauge AWG for almost everything, and reused the old negative and positive terminals. Tested each wire after finishing using resistance (my crappy multimeter doesn't have a continuity tester). and all seems good.





bike has been sitting for almost a month now.

I get everything plugged in, and my new harness fits better than the old one. used heat res wire loom, which looks nice. also replaced the old starter solenoid with a new one.

I finish up, turn the key, and no power.

I am sad.

the battery I put on my fairly cheap charger/ maintainer (everstart or something like that), reads 90% then after a minute will give me a fault code F01. which some say it means dead battery cells.

I'm just surprised I'm getting no power at all? Can a battery just crap out like that?
I'll try replacing the battery, then check all the connections. after that I have absolutely no idea what to do next.

Nice job on that harness . Hopefully its just needs a batt .My 550 would never run right without a good battery

Well, start with battery voltage. Turn it on and measure the voltage on the battery. If it's good on the battery, then it's a wiring issue, or fuse, or switch etc.

I see you have the Harbor Freight type multimeter. The meters are ok, but sometimes the test leads they come with are prone to fail very quickly. I never bought one of those meters that actually came with a good set of working leads. So if you start getting confusing readings, make sure the leads are good. If not, try to get some decent leads on ebay etc.

SO
I was out testing a bunch of things this morning. ground seems good, battery at 12.5 volts (Which the previous owner put in a new battery two weeks before i bought it ( like 7 months ago?)) but still the battery maintainer says it's faulty

I unplug the igniter unit and right as im about to take break and head inside, BOOM neutral light is ON! Unplugging the igniter unit is giving me power to almost everything, haven't tested the starter yet....

So I guess i need to figure out whats wrong with the igniter unit plugs.... i'm just really happy my harness actually works.

Ok, so I was curious about the new starter relay, and went to see if the starter would spin even without the igniter unit plugged in. But doing so cut the power, which is EXACTLY what was happening with the old harness. so the issue i don't think was the harness. Don't quite know where to go next. The starter was rebuilt and I have a new solenoid. Does the orientation of which connector goes where on the solenoid? I doubt thats the issue but just curious. i checked the fuses after I lost power and they look fine to me. also after testing the starter I dont have power again, cant seem to get it back either.

Any ideas? The only thing getting power is anything that is directly connected to the positive terminal. (White/red is the fuse box> white wire to ignition switch, and the positive side of the starter solenoid.)

Upon more testing, I found that exactly like the old harness, unplugging the headlight will give me power. Somehow I got power to the headlight when I plugged it in with the ignition on, but it didn't last long. all connections get power EXCEPT for the black and yellow wires, which is the ground right?

Testing the resistance from the negative terminal to the engine ground terminal I'll get next to no resistance (.4-.6) not sure if it matters but resistance on the bolt itself gives me sporratic results, as apposed to on the side of the terminal the bolt holds on to.

man electrical work sucks and I miss riding.

I have a new battery on the way to get rid of one variable.

no idea what to do