Topic: CB500 Solenoid wiring question

[Llanier44]

Hi everyone. I’m trying to undo a partial cafe racer conversion on a 71 CB500. I am at the point of connecting all the wiring and have a question about the solenoid. This bike falls into the “early” starting system wiring that has no neutral safety switch. In looking at the article on Common Motors, I think I understand the basics (one connection on the solenoid to the battery and one to the starter. I see the yellow/orange wire running from the starter button to the main wiring harness. Before I assume something… are the two wires in the picture that originate in the aftermarket solenoid unneeded in my application? If they are necessary I don’t know where they would be connected. I’m learning as I go and I am so appreciative of all I’ve learned already from this wonderful site. Thank you

[bryanj]

Those two small wire are what "energise" the solenoid to make it connect the two big terminals.
The yellow red goes to the loom and to the start button
The other goes to a switched live connection, usually black on Hondas

[HondaMan]

Rats, my book is late! It shows how to refurbish the OEM solenoids.

[Llanier44]

BryanJ- thanks but I can’t see where there are any places to connect to the main. The wires are pretty short- would they possibly connect into the rear of the main harness connecting “block” that’s right beside the solenoid?

[scottly]

There should be a black wire with a female terminal and a yellow/red wire with a male terminal coming from that block.

[bryanj]

Cant remember wether the connectors are on the main loom or the electric panel sub loom.

[Llanier44]

Great advice! Thank you. I will dive in again tomorrow after church.

[scottly]

Bryan, from the looks of the schematic it looks like the solenoid wires are on the sub-loom side of the connector plug.
Llanier, if you have any more problems, please post a pic of the connector. 

[newday777]

Hi everyone. I’m trying to undo a partial cafe racer conversion on a 71 CB500. I am at the point of connecting all the wiring and have a question about the solenoid. This bike falls into the “early” starting system wiring that has no neutral safety switch. In looking at the article on Common Motors, I think I understand the basics (one connection on the solenoid to the battery and one to the starter. I see the yellow/orange wire running from the starter button to the main wiring harness. Before I assume something… are the two wires in the picture that originate in the aftermarket solenoid unneeded in my application? If they are necessary I don’t know where they would be connected. I’m learning as I go and I am so appreciative of all I’ve learned already from this wonderful site. Thank you

As you are working on a partial Cafe, what is the main wire harness on it? Is it custom made or the original harness?
What does the solenoid look like?
Pictures more than the 2 wires would be better so we can get an actual idea of what you are working with.

[Llanier44]

All the wiring is still stock, thank goodness. If I can’t figure it out with the advice I’ve received, I will post more pics. Thanks again

[dave500]

the solenoid is just a heavy duty relay switch,the thumb press button would never hold all those amps,that yellow with red trace line comes from the back of a gang plug,your bike has spade connectors not tiny round bullet ones?these bikes only have one fuse aswell,i modded mine to take a simple blade type fuse.

[HondaMan]

these bikes only have one fuse aswell,i modded mine to take a simple blade type fuse.

Mine, too. The 750 looks just like that before the K3.

[Bodain]

My newest bike is a 1971 Honda CB500.....   It's a very odd duck..... At least compared to the other countless 70's Honda's I've worked on. The first thing that comes to mind is the very odd linkage making all the carbs work.... The second thing is the cheesy way the clutch works and finally the wiring seems to be a bit odd.
I'm still accessing the whole bike, but at this point I've gotten it running while on the center stand.