1974 CB360 --- No power to coils, Need help trouble shooting start circuit

mtbr

New Member
Hello All,

I have a 1974 CB360 that will not send power to the coils. I bought the bike as a non-runner. The wiring appears to never have been messed with. I have done some initial testing of the wiring with a multi-meter but not sure if I am using it correctly. The primary and secondary coils tested ok for continuity. Jumped started the solenoid and was able to turn over the electric starter.

Changes that I have made on the bike so far: removed original controls, added a start/stop switch from 2002 a VTR 1000 Honda, new battery, new ignition switch.

I need help with trouble shooting the starting circuit; how to use the multi-meter to test; whether or not I need an additional ground for the new start/stop switch; any other help with testing would be much appreciated.

Thanks :)
 
Your handlebar switch should look something like this...

2064_Honda_CB360_RIGHT_Handlebar_Switch_3.jpg


With the keyswitch on and the handlebar switch in the run position (like the pic), you should read battery voltage at the black/white wire on the coil.
 
I turned the ignition on, start/run button on, tested the voltage at the black/white wire going to the coils a got "000" for voltage. The battery is new and shows 13.6 volts on the meter.
 
Test fuses.
Red wire from battery to fuse then on to key switch, black from key sw to solenoid yellow red to start button then ground.
Also, black from key sw runs to kill sw then as black white to coils.

If fuse is bad none of this will read voltage to ground

If fuse is good and key sw is bad. Red wire will read voltage to key sw but black wire out will not.
 
Ignition system on the 360 is run from the main fuse. Assuming all of the lights come on when the ignition switch is turn to the on position, it's probably not fuse related (unless PO messed with the system).

If there is no power on the black/white wire coming from the right switch gear (when kill switch set to run), then the next thing to check for is power on the black wire going into the controls. If you have power, then your kill switch is bad. I recommend replacing it, but it can also be bypassed by plugging the black/white wire into the black wire (on the harness side) that would normally go to the right control.

If you don't have power on the black wire then you probably have a significant wiring issue to sort out.
 
I have tested the coil by running a jumper wire from the battery to the black/white wire at the coil. tested ok with coil getting power 13.2V. I was able to time the bike.

I am still not getting power from the new ignition switch that I installed. I tested the red wire for voltage starting at the battery. I was able to get 13.2 volts on both sides of the 15Amp fuse in the fuse box. Then I unplugged new ignition switch from the plug. Tested the red wire at the plug and got zero volts. I tried jumping the red and black at the plug. Still no power going from the black wire.

I'm stumped. Shouldn't I be getting 13.2V at the plug on the red wire coming from the fuse box? Or am I not testing something correctly?

The wiring harness is still in factory condition and not manipulated with. Doesn't appear to be messed with.
 
Make sure you're testing the right side and the right order. Battery power goes straight to the starter for red and black. They go through the voltage regulator to the ignition switch. From the regulator, black t's off to the harness and the ignition switch. Red goes through regulator to the ignition switch. Sounds to me like your issue may be at the regulator.
 
If you have no power on the red wire on the harness side of the ignition switch then it's either a bad fuse or a bad wire/terminal. Nothing else will cause it.
 
Irk,
-How do I test the regulator?


Sonreir,
-The fuse is good. To test the red wire should I use a jumper wire from the red wire connection in the fuse box (since it tested hot) and connect it to the red wire on the back of ignition switch, then turn the key to the "on" position. Then test for voltage at the black wire on the back of the ignition switch. What are your thoughts.
 
MTBR said:
-The fuse is good. To test the red wire should I use a jumper wire from the red wire connection in the fuse box (since it tested hot) and connect it to the red wire on the back of ignition switch, then turn the key to the "on" position. Then test for voltage at the black wire on the back of the ignition switch. What are your thoughts.

You shouldn't need a jumper wire. Stick the multimeter probe in through the back of the connector and you should be able to reach the terminal.

Make sure the key is in the second position and not the third.
 
Sonreir,

-I guess that I was trying to see if the jumper wire tested good then that would verify that the factory red wire from the battery to the ignition switch was bad.

Mark
 
Worth a shot if you're going directly from the battery to the ignition switch. I probably misread and pictured you running the jumper from the ignition plug (harness side) to the ignition switch.
 
Good news! I tested for voltage from the back of the ignition connection. Zero volts. Then I cleaned the connections at the voltage regulator with electric contact cleaner. Problem solved. I now have 13.4V at the back of the ignition plug.

I have one more problem to solve. The start button on the right control "does not" energize the solenoid to send power to the starter. Here is what I have tested so far.

(Using a test light)
-Right control switch, tested for power at black/black connection - test light works
-Right control switch, tested for power at black white/black white connection - test light works
-Right control switch, tested for power at the red/yellow wire connection with the switch to ON position. - test light works. Also, tested for power at the red/yellow connection near the solenoid. test light works
-If I jump the - and + terminals on the solenoid it energizes and turns over the starter.

Why isn't the solenoid energizing when I push the start button? The key is turned to the 2nd position.
 
Might be a number of things depend on how your wiring is set up.

I can't remember the exact year of the switch over, but early Hondas use to have power going to the solenoid when the ignition switch was on and then used low side signalling to activate the solenoid. That is, pressing the starter button grounded the energizer circuit through the handlebars and then everything works. During a rebuild, it's common to miss the extra ground wire that ensured the handlebars were grounded to the frame. Normally the handlebars mount to the top triple with rubber isolators to cut down in vibration, but this also keeps them insulated, electrically speaking. The extra ground wire from the bars to the inside of the headlight bucket was needed to ensure the starter solenoid could be activated (horn works the same way). You can tell if you bike is an early model because the wire colors on the solenoid will be black for power and then yellow/red for signalling.

Later years sent power from the starter button to the solenoid and the solenoid was grounded through either the clutch switch or the neutral switch. This was an added "safety feature" which prevented operators for activating the starter motor unless the bike was in neutral or the clutch was engaged. The presence of the a clutch switch will let you know that your bike is wired in this manner. Additionally, the solenoid should have the usual yellow/red wire for signalling, but will also have a green/red wire for the ground.
 
- The control switch that I am using is off of a Honda VTR 1000 (temporarily located on the left hand side) has the two additional wires hanging off of it. Newer switch. I have an early bike. What do I do with those wires--do need them? I currently don't have my head light mounted but will later. How can I ground the newer switch so the start button will work?

Thanks again
 

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