Front brake not illuminating brake light

[doggscube]

Bike: 81 GS450S
I checked this before I bought the bike, and since then I've adjusted the rear brake (different resting stop point), and now the front brake handle isn't turning on the brake light. I'd like to get an idea where I should start in looking for the problem.

Thanks,
Jeff

 

[t3rmin]

The switch that activates the light is on the underside of the master cyl/brake lever assembly. It's an oblong plastic piece with two screws holding it on and a wire coming out.

Loosen the clamp bolts that hold the whole assembly to the handlebar, then turn it all upside-down. This is so springs and such don't fall out when you open the switch. Now remove the two screws holding the oblong plastic holder, being careful not to let anything *sproing* across the room.

Clean all the contacts inside, pack with a little dielectric grease to make it last, and put it back together. Now adjust it (it slides a bit) until the light comes on at the slightest squeeze of the lever and tighten the two screws down. Swing the assembly back right-side-up and tighten the clamp bolts.

That's it!

 

[doggscube]

Thanks! I knew my first step would be around at the handle, but advice based on experience is fantastic.

Jeff

 

[kurifu]

PO of my bike used a lot of grease under there which actually stopped the contacts from mating, had to clean them out to get it working again, watch out though, a small level will fall out as soon as you remove that bottom plate to the switch, I also found the my level had to be replaced, they are a cheap part worth about $1 though.

If that doesn't work, you will need to start checking your electrical to make sure wires and connectors are good, you can do this with a volt and ohmmeter.

 

[t3rmin]

PO of my bike used a lot of grease under there which actually stopped the contacts from mating, had to clean them out to get it working again,

Anything but dielectric grease would be Bad(tm).

 

[jpaul]

While you're at it, follow the wires for the switch to the headlight bucket. Check the connections in there. I bought a can of dielectric grease and any time I deal with the electrical system, even if it's just to move wiring out of the way for other work, I take apart all connections, clean them, and reassemble with dielectric grease. It's cheap insurance against problems due to bad connections.

 

[Guest]

Be very, very careful and watch for the spring, the plastic piece and the brass strip if you disassemble. Make sure you have a clean workspace and a sheet or something to catch them. These little @@@@'s will always necessarily fall into the abyss, never to be found again. Ask me how I know. Twice.LOL. You can just loosen the two screws slightly and move the plate around to see if it out of adjustment before disassembling the whole switch.

 

[USMC_SGT]

I just got mine to work yesterday after replacing and ohming wires for 2 hours I found the little square piece in the lever was seeding to far back. After modifying a small c-clip to help hold it out I now have front brake lights. I was just about to give up and replace it all.

 

[salty_monk]

I had to replace that little piece with spring & contact, it was deformed. I bought the whole switch assembly in the end for 15 bucks... The contacts were pretty worn out anyway....

Dan

 

[jpaul]

If you want to replace the switch, try Partsnmore

https://www.partsnmore.com/cat_index.php?model=gs&category=electrical

I bought one and think it is better designed than the original. It's made so the metal contact piece and the spring stay in the piece that slides, making it a lot easier to assemble, IMO.

 

[doggscube]

It was pretty corroded/dirty. I didn't lose any parts. Cleaned it all up and it works. Next time I'm at an auto parts store I'll pick up dielectric grease.

Jeff

 

[denydog]

Fix your brake light switch forever.

Fix your brake light switch forever.

How to make sure you never have to touch your brake light switch again. No adjustments ever!

Get one of these. I put one on after hearing about it on this forum. It's a miracle! http://www.denniskirk.com/jsp/product_catalog/Product.jsp?skuId=210370&store=Main&productId=p210370

 

[Guest]

I won't Deny you Dog on this one. I but that link on my fav and will get one in the near future. Thanks.

 

[denydog]

I won't Deny you Dog

Good one!

The only two slightly negative things about this switch I can think of, is that it costs a little more than the standard switch. It might also add just a little bit more travel to the brake lever due to the fact that the fluid has to actuate the hydraulic switch. I don't know that it's even perceptible though.

 

[Killer2600]

Good one!

The only two slightly negative things about this switch I can think of, is that it costs a little more than the standard switch. It might also add just a little bit more travel to the brake lever due to the fact that the fluid has to actuate the hydraulic switch. I don't know that it's even perceptible though.

Did it come with two switchs or do you have to purchase two of them...Not sure what the description was trying to tell me, if front and rear come for that price the cost is quite compareable to OEM.

 

[denydog]

Only one switch per package.

Funny, I never even thought of using one on the rear brake! I guess I don't see the standard rear brake switch as much of a problem, since I've never had a reason to take it apart. It's more of a self contained unit. It's only been the front switch that I've needed to take apart, due to servicing the master cylinder. I also haven't needed to adjust the rear switch that I can remember. I suppose you could replace the rear switch if you wanted too.

To tell the truth, I guess I view the rear brake as secondary much of the time.

Just make sure you get Dennis Kirk part number 21-0370 (K&S pn 12-00111) 10mm dia. x 1.00mm thread pitch
It's counterintuitive, because DK lists this as the one for European bikes. But the package confirms it's for European and Suzuki models.