No electrical power

[Skidplate]

Hi
First time owner of Cb 750. Bought with the dead battery. New battery no help no power anywhere power to start solenoid, all fuses look good
Only the 15amp showing power. Found a small diameter red wire coming from the positive side of starter solenoid taped up. Yep hot all the time. The schematic
Looks like that is supposed to go to the start switch….huh? It’s a 1974 CB7504. I’m open to any input.
Thanks
.

 

[Loose Chain]

Is the main fuse by the solenoid still good?

 

[Skidplate]

I’ve only had the bike one day and I can only find three glass fuses….. is there another?

 

[Skidplate]

I’ve only found three glass fuses under a plastic box. Can’t fine any other

 

[brettp]

It's behind one of the side covers.

 

[Loose Chain]

I’ve only had the bike one day and I can only find three glass fuses….. is there another?

Like I said, by the solenoid.

 

[Skidplate]

Damn if I can find it. Like I said there is a short red wire that comes off the positive side of the solenoid that is hot, showing power that’s taped off. But no luck finding it.

 

[Loose Chain]

Found a small diameter red wire coming from the positive side of starter solenoid taped up.

Can you take a picture of what you are looking at?

 

[Skidplate]

Here’s what I’m looking at the green wire is open which is depicted in the clymer schematic but not the red one to it’s left. The red is hot always from the battery through the solonoid….if I go with a whole new harness….any recommendations? I think I like the one on Z1.thanks.

 

[Skidplate]

The red one on the schematic indicates that it goes to the start switch….unless I’m reading it wrong

 

[Skidplate]

I’m getting no power past the key switch…ordered one will see if that is the culprit before a total rewire but it is 40 years old. Still I’m perplexed about that red wire even if the ignition switch fixes the problem

 

[brettp]

That spade connector tells me it connects to something right where it is. That isn't long enough to get to the igniting switch. What is three other end of that red wire connected to?

 

[Skidplate]

Yeah that’s what bothers me it was just hanging there taped up

 

[brettp]

How many wires are connected to your starter solenoid there? Should be 4.

 

[brettp]

Oh, and we still need to locate that 30a fuse...

 

[Skidplate]

No 30a fuse on this bike and none indicated on the 1974 Cb 750 schematic

 

[Skidplate]

Four wires on solenoid one not connected to anything… the red one that is hot. Taped off

 

[brettp]

That is a problem. The solenoid needs 4 connections to work (2 smaller ones supplying a signal, 2 for the purpose of the solenoid). Not having a 30 Amp fuse off the battery is a significant issue. It protects the entire harness.
I'm not a SOHC expert (at all), but is your diagram for K2 the same as your bike?

 

[Skidplate]

Yes,arg