Topic: 75 CB550. Riding at night and lost headlights brake lights and rear running ligh

[turin39789]

figured it out one of the photos was too big

[seanbarney41]

If you did not tear the gasket, it can be re-used.  It's unlikely that there is anything wrong with the stator.  Also, out of literally several dozens of sohc4's owned I have never seen a bad one unless damaged from a  crash...and that goes for the reg. and rectifier also.  Rectifier can be damaged by connecting a power source polarity wrong such as jump starting or incorrect battery installation.  It's nearly always a wiring problem or poor switch connectivity.

Hopefully Scottly will be a long shortly.  He is excellent at walking you though pinpointing the problem.

[bryanj]

Those fuses are too long for rhe holders and will not be a good connection, not unusual as the proper ones are an odd size.
Do yourself a favour and buy Hondamans blade fuse conversion

[scottly]

B) Started bike. At Idle I'm seeing 12.6.  I don't fully trust my tach, but the nice thing is it went from 12.6 at idle to 12.7 at the peak at very high RPMs.

With the bike put back together, measure the voltage at the white wire regulator connection, with the kill switch off, the headlight off (if you have a switch), key turned on, and engine not running. The meter black lead should be connected the battery - post. If you read 12ish volts, that's good. If not, it indicates a regulator problem.
If the reg tests OK, disconnect the white harness wire from the reg, and measure the ohms from the white wire to the battery - terminal. This checks the field coil and it's wiring. It should read about 5 ohms. Note: this test is done with the key off.

[scottly]

BTW, the rectifier doesn't have two black wires!?? Yours look to be charred black? One used to be red and the other used to be green. It did pass the test, but I would take a good look at the harness it plugs into for melted insulation.

[bryanj]

Just looked closely at that pic and the rectifier is a VERY old one of the first type changed by Honda fairly early on

[Deltarider]

Those fuses are too long for rhe holders and will not be a good connection, not unusual as the proper ones are an odd size.[...]

"Ahhh... I wondered who would be the first to spot that one."

[rotortiller]

I wondered who would be the first to spot that one

Play stupid games, win stupid prizes, not even worth the energy to comment on that one lol.

[Deltarider]

You've missed the quotation marks, the wink emoji and so you've missed the point. Bryan as well as other Brits may understand the quote. Dad's Army has been for years the Brits' favourite comedy serie. The serie has been broadcast all over the world: Canada, Australia, New Zealand, Europe. Not in the US.

[turin39789]

Just looked closely at that pic and the rectifier is a VERY old one of the first type changed by Honda fairly early on

Woo-hoo

BTW, the rectifier doesn't have two black wires!?? Yours look to be charred black? One used to be red and the other used to be green. It did pass the test, but I would take a good look at the harness it plugs into for melted insulation.

I can toss up a pic, but not charred black.  It looks like someone wrapped them finely with electrical tape.  There is some darkness on the rectifier side plug but not clearly burnt up.

[turin39789]

B) Started bike. At Idle I'm seeing 12.6.  I don't fully trust my tach, but the nice thing is it went from 12.6 at idle to 12.7 at the peak at very high RPMs.

With the bike put back together, measure the voltage at the white wire regulator connection, with the kill switch off, the headlight off (if you have a switch), key turned on, and engine not running. The meter black lead should be connected the battery - post. If you read 12ish volts, that's good. If not, it indicates a regulator problem.
If the reg tests OK, disconnect the white harness wire from the reg, and measure the ohms from the white wire to the battery - terminal. This checks the field coil and it's wiring. It should read about 5 ohms. Note: this test is done with the key off.

I got 12.56 with black on battery and red on the white post, so that looked happy.

Is there a trick to getting those connections off the regulator post? The white one doesn't want to come off and very little play in the wire.  Not sure if it is recommended to unbolt that whole electric connection panel while diagnosing or keep reaching through under the seat.  Will go try again after some work work.


Ok. I believed in myself some more and wiggled the connector until it came off.  I did black to battery and red to inside the white connector(well first I did the other way and didn't get anything).  Didn't get a reading at first, but then wiggled again. Most consistently got 0.10.  Key in ignition but turned off.

[scottly]

 Most consistently got 0.10.  Key in ignition but turned off.

The measurement from the white reg wire to the battery - post is for resistance: set the meter to the lowest ohm position, (with the upside down horseshoe symbol) and touch the leads together. This will give the lowest reading the meter is capable of. Now check from the white wire to the battery: it should read about 5 ohms. If it still reads 0.10, you've found a problem.

[turin39789]

 Most consistently got 0.10.  Key in ignition but turned off.

The measurement from the white reg wire to the battery - post is for resistance: set the meter to the lowest ohm position, (with the upside down horseshoe symbol) and touch the leads together. This will give the lowest reading the meter is capable of. Now check from the white wire to the battery: it should read about 5 ohms. If it still reads 0.10, you've found a problem.

Ohhhh!!  You wanted me to use the multi-meter correctly. I was one setting over, all ready to test a diode.

Set the meter to the 200 horseshoes and I'm getting a reading of 9.9.  Have to wiggle some to get a reading, trying to think through how to clean this connector(blade style, no slack in wire, plastic cover), but after a few tried I am consistently reading at 9.9.  Again that is red lead to the white connecter, black to the negative terminal on battery.

That's still out of spec, so check connection at field coil and if those wires look ok then replace?  Seems a pricey part.  Or can I service?  Visual inspection of how far I have it open so far and I see a little brown/discolored patch but I have no idea if that is expected.

[turin39789]

Went ahead and unplugged the field coil and checked between the two and reading 4.9.  Now I hope I can plug them back in successfully.

[turin39789]

So I tried the white wire direct from regulator wire to positive but no charging still.  My caveat is I still can't get the bullets to push together well from the field coil to the harness. Is there a trick there or do I have to take more of the case off?

[bryanj]

Those black wires aint supposed to be, one is red the other red/white

[scottly]

So I tried the white wire direct from regulator wire to positive but no charging still.  My caveat is I still can't get the bullets to push together well from the field coil to the harness. Is there a trick there or do I have to take more of the case off?

You need to make sure the bullets are fully seated, and then be able to measure 4.9 ohms from the white wire at the regulator end to the battery - terminal. If you still measure 9.9 ohms, measure the resistance from the green reg wire to the battery - terminal. It should be zero ohms, or whatever your meter reads with the probes connected together.

[turin39789]

So I tried the white wire direct from regulator wire to positive but no charging still.  My caveat is I still can't get the bullets to push together well from the field coil to the harness. Is there a trick there or do I have to take more of the case off?

You need to make sure the bullets are fully seated, and then be able to measure 4.9 ohms from the white wire at the regulator end to the battery - terminal. If you still measure 9.9 ohms, measure the resistance from the green reg wire to the battery - terminal. It should be zero ohms, or whatever your meter reads with the probes connected together.

Ok. Probably doing this wrong still. Or we have our problem.

Pretty sure Stator plugs are back in and snug.

From the white  post on the regulator to the post on battery I am getting 8.4-9 ohms.

From the white wire I get 0.

From the green post I get 44, from the green wire I get 12.6.

All with key in off position, both green and white wires disconnected at regulator, black still connected.

[scottly]

from the green wire I get 12.6.

All with key in off position, both green and white wires disconnected at regulator, black still connected.

Yes, that is a problem. First, measure the resistance from the neg batt post to one of the screws on an engine side cover. This tests the big fat wire from the battery to the frame and engine: it should be zero ohms, or very close to zero.
If that checks OK, you need to check the connection where the harness green ground wire attaches to the frame. It may be under the seat near the battery, or under the gas tank at a ignition coil mount.

[turin39789]

from the green wire I get 12.6.

All with key in off position, both green and white wires disconnected at regulator, black still connected.

Yes, that is a problem. First, measure the resistance from the neg batt post to one of the screws on an engine side cover. This tests the big fat wire from the battery to the frame and engine: it should be zero ohms, or very close to zero.
If that checks OK, you need to check the connection where the harness green ground wire attaches to the frame. It may be under the seat near the battery, or under the gas tank at a ignition coil mount.

So I took the tank off looking for where that ground connection is. Didn't quite find it but I found the problem or maybe a symptom.

[scottly]

Whoa!! It looks like there was arc welding on the frame there, or is that something in the pic?

[turin39789]

Whoa!! It looks like there was arc welding on the frame there, or is that something in the pic?

Definitely looks like it. I should note that at this point the battery is dead dead. not sure if this was a problem in the works it just got worse or if I did something during testing procedures to exasperate or cause this

[scottly]

Did you smell any smoke during your testing?

[turin39789]

Did you smell any smoke during your testing?

No and I would say 5 days ago when I was fooling with it the battery was full charge and would start up other than not charging.

I'm pretty certain I got stator wires in right bullets this morning. But I don't think that would cause this evening if I mixed up. Otherwise it's just been sitting.

I do have the original harness handy. I had a slow discharge problem for awhile so in 2017 I decided to throw parts at it and ordered a new main harness from 4into1.

In 2020 after never doing anything with it, I had the local shop put it in and clean up electric. Everything seemed sorted but after some time I lost turn signals again.

So I've still got the OEM harness which was probably fine to begin with. I think some of the downstream wires to signals etc are a mess in the headlight and tail, but I may just clean up the connection on the original harness and reinstall slowly and try to get everything right.

[turin39789]

I also got a new battery about a year and a half ago, a motobatt off Amazon.  But it died and failed so I replaced it direct from motobatt back in June. I chalked that up to possible counterfeit from Amazon as other than turn signals it seemed to be fine.

I connected the tender out of curiosity but no charge either because fully discharged or the melted ground.