No power when turning ignition switch to ON position - 1977 CB750 F2

[Stratmanx]

Did a 70 mile ride yesterday, s few stops along the way with no issues.

Last stop was at Northern Tool, shut off the bike, locked the steering. Went to unlock and turn key to ON position and no power.

I also noticed it wouldn't going into the P - Parking lights, position.

Could it be the wafers inside the switch finally went bad ?

Fuses are all good and getting power.

Connector to the switch is solid and tight, no breaks or chaffed wires.

If so, where can I find a direct replacement for the switch assembly and is there a procedure for the removal and reassembly of the unit ? I've got the shop manual, but It doesn't appear to cover that.

Thanks all !

 

[Loki]

I think it is possible to seperate the switch part from the lock part, there might be security screws to overcome but that's easily overcome.

Loki

 

[Stratmanx]

I figured out what was up. the main plug connector has got an issue, in that if you put upward pressure on it from the bottom youve got juice.

I had replaced all the connectors on the loom side of the connector as there was broken wire from that acute bend where it goes into the plug.

I'll get back in there and check all those connectors and make sure all is secure.

It still doesn't account for the key no longer going into the P position.

 

[hinksy]

It sounds like the switch has failed and that could be why it wont lock in park . I have seen replacements for sale on most sites , but that could mean different keys . Two bolts to remove it , plus the plug . But you have to remove either the headlight or guages first

 

[Stratmanx]

Ignition switch out of the bike

Trying to get that connector out by itself is an exercise in frustration and futility, trying with any number of different angled tools it’s damn near impossible

The headlight assembly has two bolts under the side reflectors, unscrew them and the entire assembly drops down giving you pretty good access to the two 10mm bolts holding the switch assembly to the bike.

They don’t appear to be sacrificial bolts so I believe just standard.
Lining them up and getting them back in will be a bit of a chore due to the wiring harnesses, but doable

Do yourself a massive favor and pull the switch assembly if you want to work with the connector. You'll save yourself MUCH heartache !

Ordered a drop in replacement w/ 2 keys - $31

https://vintagecb750.com/collection...ntact-points/products/ignition-switch-12-0051