R90 Front Brake/Stop Light Not Working

[Ron from BC]

'76 R90/6. Recently discovered that the brake/stop light does not come on when the front brake is applied. Rear brake pedal activates the light fine.

I put a multimeter on the front brake switch, at the MC under the tank, and it is fine.

Other than following the wires from the switch to look for a short/ground any other ideas?

Thanks

 

[Posh Pete]

From memory (nearly 40 years!), the light is activated via a micro switch in the front brake assembly? The brake lever presses on or releases a plunger in the switch? Have you looked at that? It may be clogged with crap which prevents the plunger moving?

 

[DrFarkoff]

are you sure it is actually working ?

does it make and break.if you check it with the OHMs setting?

you said it works on rear pedal it's one cicuit so that means the connection to the rear is okay

What happens if you join the wires?

 

[Ron from BC]

1. The switch on this bike is at the forward end of the MC which is underneath the tank. It has two spade terminals at the front which are clean.

2. Good idea to connect the two disconnected wires from the MC. The brake light should come on when that is done....right?

 

[DrFarkoff]

2. Good idea to connect the two disconnected wires from the MC. The brake light should come on when that is done....right?

Ron maybe use a blade type fuse of about 3 amp as a bridge just incase there is a nip in the wire

if the fuse blows you can trace the wires and find fault

If the lamp lights change the hydraulic switch

Just make sure with the ignition on that you have 12v positive down one wire

 

[Ron from BC]

Ron maybe use a blade type fuse of about 3 amp as a bridge just incase there is a nip in the wire

if the fuse blows you can trace the wires and find fault

If the lamp lights change the hydraulic switch

Just make sure with the ignition on that you have 12v positive down one wire

Will do thanks..

Just noticed where you were from. Beautiful area, I actually visited there a long time ago and had dinner a La Mon restaurant in County Down.

 

[Ron from BC]

Success

Well first I had to go into an old lady's knitting basket, also known as the headlight bucket, and wire up all the connections from my new right hand combination switch. That done I put a wire, with 3 amp blade fuse in line as you suggested, between the two wires to the blade terminals on the switch on the MC.

Voila! The brake lamp does in fact light....so the good news it is the switch and a cheap fix.....the bad news is I have do read more on how to use my multimeter

So now it's off to the local auto parts store for my aftermarket switch.

On a side note, it sure is nice to feel a positive click when I turn on the indicators now. I lost the detent ball from the old one years ago when I was restoring this old beast.

Thanks Dr. F