Topic: Wiring CB750F1 1976

[spitfire]

Hi guys,
           Even though I took a load of photos while I stripped my bike down I do not have one which shows clearly which electrical leads go into the junction box on the front  frame downtube. Obviously the big branch from the main wiring loom goes in there but which others ? One of my photos clearly shows a lead coming from the headstock area going into the top of the box, but I'm not sure which and there does seem to be an awful lot of connectors from the main harness going in there !

Cheers

Den

[SD750F]

Spitfire,

Do you have a good wiring diagram for your bike? If not email me and I will provide a GIF for you.

Scott

[STLrocker]

what is this jnction box you speak of? i dont know of any box on the front down tubes.

wiring diagram:

http://oldmanhonda.com/MC/WiringDiagrams/MCwiring.php#class

[ofreen]

One of my photos clearly shows a lead coming from the headstock area going into the top of the box, but I'm not sure which and there does seem to be an awful lot of connectors from the main harness going in there !

There are a lot of wires stuffed in that little box.  Let me know if you are still stumped and I'll post a pic of mine.

[spitfire]

Hi Greg that would be great, at a guess I would say that the leads from both handlebar switches and the horn go into the box, but a photo would be very usefull.

Cheers

Den

[bryanj]

Main loom, headlamp loom, idiot light box, both handlebar switches, brake light switch and horn, or to put it another way EVERYTHING and boy is it a tight fit!

[ofreen]

Here are some pix.  Hope they help.  You can see the wire colors.

[ofreen]

Here is another view from the top.

[spitfire]

Thanks Greg,
                   Apart from the main wiring loom how many other leads go in there ?

Cheers

Den

[ofreen]

Two others, including the horn wires and another big wad of wires on the upper left as you look at the picture ( right side of bike.)  The big brown wire you see on mine isn't stock, it leads to the relay I use for the horn.

[SD750F]

Does anyone else wonder what the relay is used for in the main harness cluster? It looked like a standard automotive relay housing to me?

Scott

[ofreen]

Does anyone else wonder what the relay is used for in the main harness cluster? It looked like a standard automotive relay housing to me?

Scott

If you are talking about the relay in my picture, it is a relay I installed to run a Fiamm horn.  It fits in the wire box.

[spitfire]

Thanks guys,
                 Think I've got it sussed now, laying the various bits of harness on the bench makes it a bit easier, the harness from the idiot lights is very short and looks like it goes into the headlamp shell, the two harnesses from the handlebar switches are longer and go to the junction box, the clutch cut out looks only long enough to go to the headlamp shell, and the horn can only go to the junction box and the number of connections seem to match up.

Thanks

Den

[SteveD CB500F]

I'm pretty sure that the F1 had the "new" slimline headlamp shell so everything that the rest of use jam back in there goes in the extra little box...

[spitfire]

Hi Steve,
           Yep your right it's just stuffing all those wires in there that is the problem !
One thing that I did do was to scan the wiring diagram from the original handbook that I got with the bike and converted it to jpeg, this is great as I can zoom in on it and check through any bits I'm not sure of.
If it is usefull I could send you copies for the site, they are too big to post (1,677 kb) and lose definition if you shrink them. Have got CB750F (UK-SWEDEN-EUROPEAN TYPE) CB750F (GERMAN TYPE) and CB750 (AUSTRALIAN-GENERAL TYPE) diagrams. Could not find any wiring diagrams on the site or am I looking in the wrong places !

Cheers

Den

[SteveD CB500F]

Den. Email them to me (address in Profile).

I'll see if we can post them here.