Topic: 1975 CB550 wiring questions

[Sprocket75]

  Good day to everyone! First post and this might be a doozie! Im a new member who recently acquired a 1975 Honda CB550 and I am going to try to start bringing her back to life. This place seems like the right place to turn to for help/advice, so here goes...
 The previous owner informed me that it was running last year, but that it had a "charging" problem. (not running now) Anyway, after I got it home, I started looking things over, and pulled the battery out. I cleaned the posts and placed it onto a charger. In the meantime, I removed the left side electrical cover and started checking things over. I took a few photos to start with hoping that someone here might be able to shed some light on what the previous owner did to the wiring. (and why?) So here are some photos that I took this morning. Also, after the battery was charged and tested, I reinstalled it. I noticed that one of the fuses in the fuse panel was missing (5AMP, far left side) so I replaced it with a new fuse. I put the key in the ignition, turned it on, and then turned on the handlebar switches. The left turn signal illuminated solid and there was a steady "beeeeeeeeeep" and the high beam indicator light was also illuminated.(blue) After about 5 seconds, the lights went out and the beep stopped. Then nothing. I took a volt meter and tested the battery, it was fine. I then noticed that the fuse I had just installed was blown.  A short possibly? Or something pulling more than 5amps of current...??  Anyway, after seeing the wiring, hopefully someone can shed a little light for me. I have several photos, so I will start with a few...don't want to scare anyone.     Thanks in advance!

[Sprocket75]

So, I spent some quality time with her last night. Started checking over the wiring and used my toner/tracer to track the wires. After some digging, found out that two of the wires in the ignition switch had broken free of their solder joints. (the brown and the brown/white wires...util1 and util2) Took a bit of time and patience, but after removing the ignition switch, I was able to solder them back on. Reinstalled the switch, turned the key, and voila! Lights! I then bypassed the safety switch with a jumper (thanks Hondaman), made sure she was in neutral, pressed the starter button and sure enough the starter spun right up. Of course, the engine would not start, but hey, I am that much closer! I did notice that the left side blinker works and the beeper but the right side are both completely dead. The 39 year old horn still works! HA! The brake light from the front brake handle works, but the foot brake light switch does not. High beams work, low beams do not. Also, the oil pressure light illuminates, and then goes out after the starter is pressed. The neutral light seems dead, even with the bike in neutral, but I think this is probably a bad bulb. Will test the wires/switch later to be sure. I made certain gas tank was clean and added some fuel...but I may have an issue with the fuelcock...need to remove it and clean it I think.  So now it is time to turn my attention to the ignition system and alternator. I I have been reading the forum info so I will try to absorb as much info from that as I can. I will post results soon. If anyone has any advice, feel free to let me know. it would be greatly appreciated. The screws that hold the stator/rotor cover were screwed on by Zeus himself, so they will take some time to remove. Same for the ignition points cover. Sprayed them with penetrating oil last night, will try again today after work.

[Bankerdanny]

Get a hand impact to remove those screws. If you just try and muscle them off with a long screwdriver you will almost certainly strip the heads.

You are on the right track with the electrical. Just keep tracing the circuits with your meter.

If you haven't done it, download the factory repair manual, there is thread with the link at the top of the SOHC/4 Bikes board. The manual includes instructions on how to test the charging system.

[Duanob]

Here are a couple of things that will help.

This is an escellent FAQ on charging systems as well as a good source for electrical componenets for your bike.

http://www.oregonmotorcycleparts.com/FAQ.html

And we would all be lost without a schematic: Caution: some of the wire colors don't match up but you can figure it out.

[Sprocket75]

 Bankerdanny: I do have a hand impact...its old and basic, but should do the trick. I do have parts of the manual that I have downloaded here and there and it provides a pretty good reference. The FAQ's and How To's here are great and I have been reading through them like a college kid on coffee. Thanks for your help!!

Duanob: Thanks for the link!  This will definitely get me in the right direction. Also, thanks for the schematic. I downloaded it and have blown it up 75% on the plotter printer at work....makes it EASY to read. lol. I also have a VERY detailed black and white schematic that has been a tremendous help. (from the Honda Service Manual) It is slow going tracing and troubleshooting all of this wiring, but a necessary evil no doubt. I think I will take a look at the kill switch first and the RUN switch since they are both in the right side unit. Besides, the throttle seems like it is nearly stuck, so Im certain a little sandpaper and lubricant are in order. Cables look good though! Once I get that sorted out, I will turn my attention to the left side unit and check the connections/functions in there. From there, I plan to move to the ignition system. Quick note, on my rectifier, there is a solid RED wire soldered in the middle on the back (where the green wire normally is) It looks like the previous owner simply replaced it with whatever color wire he had available. Anyway, this wire is just hanging there...not connected to anything. Any particular reason why he would have done this? (just guessing?) I plan to reconnect it as it should be, just curious.  He even pulled the corresponding pin from the plug.   
Anyway, thanks for the help!

[Sprocket75]

Decided to focus my attention on the ignition coils last night as I wasn't getting any spark when trying to start her up. Take a look at the photo. Would this affect the ignition spark?   

[Bankerdanny]

Well, not having the boots on the wires probably severly limits spark   

You should have enough cable length to trim about 1/4" off of each wire to get a cleaner connection at each boot.

[Sprocket75]

I thought that might be the problem.      Anyway, I figured while I had the assembly off, I might as well upgrade the wires, right? (No?) I read through the tutorials, and I see that you can drill out the coil packs, and insert new wires via a home made copper pin. Do you guys recommend doing this? Its within my skill range, just curious if you all think that it is worth doing. Also considered upgrading the coils to Dynas with the 5 Ohm resistor wires, but its kind of pricey. However, if it is a worth while upgrade and provides more reliability, then I am willing to shell out the $$$ to do so. Otherwise I will keep the stock coils and wires...or keep the stock coils and replace the wires.  Any suggestions?

[Black 750K8]

NGK make a splice connector so you can cut the wire a few inches from the coil and put on new wire. I have them now for two years they work fine.

[Black 750K8]

http://www.z1enterprises.com/ListItems.aspx?keywords=NGK+splice

Z1 has every thing you need I would get new end caps 7mm copper core wire

[Sprocket75]

Thanks Black! Awesome site! 

[Sprocket75]

Went by the local Honda shop on my lunch break. They actually had the 5K NGK boots in stock as well as the spark plugs. They even had the tiny bulbs for the idiot lights (two of mine are burned out) Then I went by the Advanced Auto Parts and bought a set of custom 7mm silicone Accel spark plug wires. (copper core/stranded not solid) So I can either cut open my coils tonight and solder/pin the new wires OR can order the NGK splicers and wait... Im not crazy about the bulky look of the splicers, but then again, you don't really see them much, and they do allow the wires to be replaced easily. Decisions....

[Black 750K8]

You can not see mine unless you get down really low or lay down on the ground. If you start digging into the coil you can open up a real can of worms.

[Bankerdanny]

Unless there are actual problems, I think replacing the wires is just a case of fixing something until it breaks.

[Sprocket75]

 Another evening spent with her and some real quality time! I decided to keep the original wires, and replace the boots and plugs. Got everything connected and re-installed. Battery-check... Key-ON... Fuel-Check... Choke-Check... Pressed the START button and suddenly, she coughed...sputtered...and BLAT! BLAT! VROOOM!  She started! I turned the choke off, she settled down and cleared her throat. I twisted the throttle a bit and she started to sing and smoothed out. Man what a sound! Nothing like 39 years of history waking up! I blipped the throttle gently a few times, and the carbs didn't seem to mind. She does idle a little rough, and wants to settle below 1000 RPM and will sputter if you don't hold the throttle just slightly open. Most likely just some adjustments needed. Not bad...not bad at all. So, I know she has life left in her and she certainly has potential. Now the hard part is going to be hunting down the Gremlins in the wiring, and this bike is FULL of them. Sheesh! I discovered that when the previous owner installed the ape hangers, that he cut the factory wires on the left side to run them through the bars. He then soldered everything back inside of the headlight bucket using ALL RED WIRE! What a nightmare. So, the left turn signal works fine, but when I press the right turn signal, the bike shuts off. Odd. Obviously he got something crossed somewhere.    So now begins the painstaking process of tracking down the gremlins. I won't even begin to tell you what he did to the right side switches and kill switch...what a mess. But hey, SHE LIVES!!!!

[Sprocket75]

What a night...  Well, I was able to smooth out the idle by making some adjustments to the carbs. Much better now. So, now that I know the engine is mostly sorted out, I turned my attention to the wiring. Man, what a headache! So, first things first. I need help with this one. The left hand switch that houses the turn signal seems to have an issue. When I switch the left signal on, the blinkers work fine. When I turn the right side on...nothing. So, I disassembled the switch (see photos) to troubleshoot. The wires were soldered on by the previous owner and I believe he may have made a mistake, but I need someone who really knows these switches inside and out to take a look for me. If I understand the diagram correctly, the BROWN/WHITE is the hot feed. I see where it is jumped from one end of the pins to the other via the small BROWN/WHITE jumper wires. I unsoldered one of the BROWN/WHITE jumpers to test, and sure enough, that side works. So, that tells me that there is indeed a short somewhere. (the fuse does not blow though) I see there are two rows of pins...they look completely separate, but does anyone know if they connect somewhere inside the circuit board? Was thinking this connection might be the cause of the "short". If I slide ONLY the top pin switch, the blinkers work! (both right and left) But if I slide BOTH top and bottom, they short out. I checked to make sure that there were no shorts in the wiring runs from the front to the back, and didn't find any. I went ahead and completely removed ALL of the wiring from the headlight bucket after tagging each wire. I am going to pull the old handle bars off tonight and install the new handle bars, and I was thinking that possibly the brown and white striped HOT lead might be somehow grounded inside of the bars. I also discovered that the green ground on the coils had been burned at some point, so I will be replacing that tonight as well. I may just go ahead and rewire the entire bike this weekend. For the most part, the factory wiring looks to be intact, so Im not really sure that will be necessary. I am open to ANY and ALL advice here. On a side note, I am NOT looking forward to re-assembling that switch.

[Sprocket75]

http://www.z1enterprises.com/ListItems.aspx?keywords=NGK+splice

Z1 has every thing you need I would get new end caps 7mm copper core wire

Ordered my NGK splicers yesterday! Thanks again for the suggestion!

[Sprocket75]

Still having an issue with the turn signals. Can anyone out there take a look at the pictures of my switch and tell me if it is soldered correctly? Or at least tell me how (in theory) it is supposed to be wired? I was looking at the wiring diagram I have and it "looks" like my switch is correct, but Im still having the problem, so something has got to be wrong.

**Update** I just realized that these bikes have RUNNING LIGHTS! I cannot believe I did not realize this.    This makes sense now as to why the lights come on and stay on. (at least the left one, the right one has issues I guess) But anyway, these are dual filament bulbs which now makes even MORE sense as to why one wire is brighter than the other when testing them with voltage! Now I just need to figure out how to wire them to the switch. I know they are color coded, but the color scheme is not working like it should. I think the PO changed some things.

[Vinhead1957]

Running lights would be on a switched power line direct from a fused line turned on by the key. Always on when the engine is on. Check other models of that year wire diagrams. Honda used the same colors in usage.  Left blinkers orange right orange.    Or vice versa.

[Vinhead1957]

Here's one schematic fm my bike.

[Sprocket75]

Thanks Vin! I was able to get the turn signals and running lights working on both sides last night. Now the issue that I am having is the ignition key sequence and starter button. So, when I turn the key to the first position, the engine oil light illuminates, and the start button works. Running lights do not, tach and speedo lights do not. When I turn the key to the second position (all the way ON) the running lights come on, the engine oil light goes out, and the starter button does not work. I realize that they key feed is backwards somehow, but if I swap them, I get the same result. Checked the fuses...they are good. Seems like there is no secondary position on the ignition switch that supplies voltage to the correct components of the circuit at the correct position. Well, on top of that, I don't know what items are supposed to illuminate/have power for each key position. That would definitely help. So, on the first key position, are the lights supposed to come on or only on the second? Should the starter work in EITHER 1 or 2 position? What about the dash panel indicator lights (engine oil)? Headlights? Tach and speedo lights? ( 1 and 2 or just 2?) Can anyone out there help clarify this for me?

[LesterPiglet]

On Euro bikes the second key position only illuminates the rear light(parking at night), I think it's the same for the US.

[Sprocket75]

Thanks Lester! So, the second position should not illuminate or provide power to anything other than the rear tail light? So, I should start my bike only on the first key position, correct? I have never owned a motorcycle before, so this is all new to me. On a car, you have to turn the key past the 1st and 2nd position to get to start, so I assumed a bike was the same. 

[LesterPiglet]

The bike will run in the first position only.

[Vinhead1957]

The middle position is run position.   Check the inside of the headlight bucket.  The orange/white and blue/white should have power at the run position.  Keep your kill switch in the off position to protect the points!