Help repairing front brake switch..it fell apart

Rebuilt my master cylinder on my 1981 XJ650. During disassembly, I accidentally opened up the brake light switch and the components fell out. A spring, brass colored rod and two black plastic spacers fell out. How does it reassemble? I tried to put it back together, but now I blow fuses when I engage the front brake and no brake lights.

 

This was the inside of my master cylinder before I rebuilt it. PO said the front brake barely worked.... hmmmm

 

Ya. That needed a rebuild kit and a thorough cleaning. Clean and rebuild the caliper as well, and replace the brake lines. New front brake switches run around $7.00. Yours is not disassembled; it's broken.

 

that photo may belong in the PO hall of fame please post a photo of your caliper before you rebuild it

 

It looks like a dirty casserole dish from a dish detergent commercial. Mebbe lasagna in there?!?

 

Rebuilt the caliper roday. It was actually in pretty good shape. Ordered a new switch, will be in soon.

 

Installed the new switch today. Start the bike, and I notice the brake light is constant on. Hit the rear brake, and the brake light goes out. Hit the front brake, and I blew the fuse for 10A Signal. I'm at a loss, need a suggestion. The front brake switch wires are hooked to the correct wires in the headlamp housing. Did I fry a relay?

 

both switches on at same time should not blow fuse unless you have a short
you are looking for a short in bulb socket or wire going from switch to bulb socket
sounds like you have a short in the front brake wire to bulb see if it is pinched someplace.

the rear light bulb has a dual filament. running light is always on . if the brake light is on without hitting the brake you may have a bad switch. when you close the switch it brings power into the second filament which acts as a resistor then to the common ground, the bulb base, the light goes on .
disconnest both brake switches ,

remove both bulbs
turn on power
use a multimeter connect meter to ground and with other probe see if you have 12 volts to the wires going to the switch you should have 12 volts on one wire on each switch and it should be the same color.
turn off power
now do a continuity test from the metal shell of the bulb socket to each dot you should get nothing. if you get a beep you have a short in the switch wires
now do a continuity test on the other wire of the brake switches(no voltage wire) to bulb socket one of the little solder dots you should get a connection 0 ohms or a beep if your meter has a beep test the other brake switch wire same color should get the same results.

if you have continuity put the bulbs back in, now use a jumper wire and connect rear brake wires together where the switch would plug in brake light should go on (light got brighter) . now test front brake light the same way.
now test your switches connect probes to switch wires cycle switch you are doing a continuity test 0 ohms or a beep. switch good, do other switch.

if all is good connect front switch turn on power test lever light should get brighter turn off power
disconnect switch
plug in rear switch turn on power test. light works your good.

 

link to wire digrams
http://members.tripod.com/dave_jack/wiringdiag/d7a.jpg

http://members.tripod.com/dave_jack/wiringdiag/d7b.jpg
block 29 and 30 are your brake switches
27 are brake lights
notice where yellow wire has a dot then connects to green and yellow those are the wires that bring voltage from switch to bulbs
fuse labeled 9 is the other wire that brings voltage to switch can not tell color
also notice switches are n.o. normaly open.

 

would like to add a correction front brake switch is n.c. normaly closed when off bike. when installed it is open until brake is applied.

 

XJ550H, thank you for the replies. I was able to fix it today. Did all the tests you suggested, everything checked out. However, I figured out that the front switch plunger was grounding out against the brake lever, causing the fuse to pop. I put electrical tape over the plunger and between the lever and switch and I haven't had a problem since.