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Discussion Starter · #1 ·
I'm in the process of puting my cb350 back together. I am wondering if there is a way I can test my electrical conections with out runing the bike since the motor isn't in it? Basically I just want to turn on the headlight, blickers, horn and brake light to check to see if my connections are correct. I tried hooking up the battey cables and turning on the ignition switch but that didn't work. Any suggestions??? Yes, the battery is good

Thanks, Matt
 

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With the engine out, you should still be able to test / operate all the electrics except ignition (points), charging, and neutral light.

All else should work.

If you've hooked up the battery and turned on the switch and get nothing, you've ID'd the first problem... :)

Kirk
 

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If you are sure the battery is good, check the fuse...Then check that the ground wire from the battery ACTUALLY touches BARE metal of the frame.... A new paint job can cause a multitude of bad grounds....Paint does NOT conduct well...LOL... Steve
 

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Yeah, but when you're installing those ground cable bolts it seems like a crime to scrape away that nice shiny new paint!!!
 

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I use a small sanding disc (Dremel) and apply dielectric grease to "slow" the rusting....
A split lock washer will also usually "cut" through just enough paint to give a ground, and removing a bit of paint allows the bike to run instead of just looking good...LOL.... Steve
 

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Discussion Starter · #9 ·
Gentlemen,

My electrical problem still lerks. I borrowed a volt meter from work and my battery reads 13.1. I removed the paint and hooked up the ground like it was before, and still nothing. I am pretty clueless when it comes to the electrical stuff, so please bear with me. Any suggestions on what to check next?? I have a feeling that my problem is leaning toward another homer award. :D
Also with the volt meter if I were to check a specific wire, what do I touch the red and black leads too. OH I already told you I'm clueless about this topic.
I'll post pics if need be.
Thanks, Matt
 

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Peel the rubber "cup" off the back of the ignition switch..... Hook battery positive (B+)to red wire on harness, hook battery negative (B-) to ground strap (heavy black wire to engine bolt).... With key off, ATTACH black voltmeter probe to B- on battery..... "Track" along the red wire with the red probe, starting at B+, then first exposed joint (closer end of fuse), then far end of fuse, then at red wire (at solder joint) on bottom of switch....
You should get the same 13.1VDC reading at ALL those points along the harness.... IF NOT, the problem lies between the previous touch point and where the power disappears......If you DO, great, you have power to the ignition switch......
TURN KEY ON..... Continue red probe "touches", starting with the solder dot of the thin black wire on the ignition switch.... Voltage there means the switch worked, lack of voltage means the switch is bad....(IF none, "jiggle" key, the switch may be dirty inside)....
IF the switch is good, follow the thin black wire (power wire when key is on), checking at every joint...The reading MAY drop to 11.5 VDC (if the coils are energized), BUT that's OK if you are still getting a reading....
If your "kill" switch is in the run (on) position, you should also get a voltage reading at the black with whitestripe wire at the coils......and check at every thin black wire joint.(inside headlight shell, at rear brake switch, etc)
Where ever the power fails,(no voltage reading), the problem is between where you now are and the last good reading point.....If ALL the thin black wires (and the black/white stripe wire) show power, whatever does not work is due to THAT individual component, OR its switch, or the wires leading to them.......
You may phone me if you want a step-by-step while you test this.... 540-525-5199
Let us know the results of this test!...... Steve
 

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I'd double check the fuses. I've had fuses that looked good, but it wasn't when I took it out, and held it to the light that I saw it was bad. Electrical contacts on these old bikes can oxidize and short themselves out too. Disconnect, clean, and reconnect is sometimes all it takes.

There you have it; The extent of my electrical knowledge. :(

Now you know why they don't call me Grasshopper :D
Allen
 

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Grasshopper.... (Allen).... The tests I discribed (last post on page 1) automatically check the fuse by reading for power at both ends...... LMAO!......Now, as quickly as you can, snatch the pebble from my hand......

MATT.... Please go to last post on page1..... Steve
 

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Discussion Starter · #13 ·
I wasn't getting any reading anywhere on the harness. I thought I had everyting hooked up as it was before tear down but just in case I looked at some photo's that I took during the tear down. Found one that identified my problem, I had both positive wires connected to the starter switch. (refer to photo), the black wire to the right coming out of the frame was connected to the top of the starter switch. I simply put it where it was supposed to be and everything was working. With the exception of the blinkers the rear ones where opposite the front, easy fix.



Steve I did what you suggested just to see what you meant by it and it made since. Thanks again for all the replies. I am so pumped that it was an easy fix. I hate electrical issues.

Matt
 

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NE350 said:
I had both positive wires connected to the starter switch. (refer to photo), the black wire to the right coming out of the frame was connected to the top of the starter switch. I simply put it where it was supposed to be and everything was working. With the exception of the blinkers the rear ones where opposite the front, easy fix.

Matt
So you're try for consecutive Homer Awards???

Gotta do better than that to get one two months in a row.
:roll: :oops: :shock: :eek:
 

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I bought an Oregon Motorcycle Products rectifier and on his web site he has some great info on testing the Honda twins charging system. Here's some info for the site.

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

How do I to test a rectifier?

Start with one lead of the meter (or test light) to the positive lead on the rectifier. Touch the other test lead one at a time to each of the
AC terminals of the rectifier. At this point you will either have continuity or not but it should be the same with all the AC terminals on
the rectifier.

Swap the test leads (still working with the positive terminal of the rectifier) and repeat the test. This test should have the opposite
result as the previous test. Again the result should be the same for each of the AC leads.

Move on to the negative lead off the rectifier and repeat the 2 previous tests. This is test is easier with a test light than with an
electrical meter. The point is to check that power flows one way but not the other and the exact numbers isn’t as important. If your
meter has a buzzer for continuity, this works very well too.

This will catch a bad rectifier 95% of the time. The rest of the time they only fail under load and will usually get pretty hot.

4. Charging system diagnostics for older Honda singles and twins (Pre-1978)

First off, read the above articles. These things all need to be dealt with when you have a charging system problem.

There are 3 wires from the stator and depending on the year of your bike they will be different colors. From 1969 on the colors were
pink, yellow and white. The pink wire connects to a full charging coil, the yellow to a 2/3rds coil and the white wire to a 1/3rd coil.
The yellow and white wires connect in the headlight switch when the lights are turned on. What this means to you is that the
resistance from pink to white will be a little less than pink to yellow. You should get around 3/4 to 1 ohm from yellow to pink and
somewhat less from pink to white. None of these 3 wires should have continuity to ground. Check the stator with an ohm meter and
if it passes these test then move on to checking the connections.

The white and yellow wires from the split coils are connected together (in the headlight switch) when the headlight is turned on
directing more power into the charging system. If the switch fails the charging system will not give full output. To make this more
confusing, most pre-1969 Hondas use the same system but with different wire colors from year to year and sometimes model to
model. On these bikes the brown wire usually represents the full charging coil and yellow and pink wires are from the split charging
coil. The best way to be sure is to check the wiring diagram in a repair manual for your bike. The best fix is a new switch but they
are usually no longer available. Some people bypass this and connect the white and yellow wires together at the rectifier giving full
charging all the time. This is only a good idea if you ride with the headlight on all the time.
 
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