Brake Light Switch Problems

[Norton Commando]

I have a heck of a time keeping a pressure switch for the rear brake light on my 1990 FLHS working for more than six (6) months or so. It seems that all the replacement switches quit working after about that same time frame.  And it doesn't seem to make a difference if I use aftermarket or HD switches, they all fail within six months or so.  This has been a chronic problem for the past 24 years.

So I'm ready to try a different mechanism to activate the rear brake light.

Has anyone converted to a mechanical switch and if so, would you please post pics of how it's rigged up?

Thanks!

Jason   

[packrat56]

     I went threw this on my shovel, But only in a month, get one at the auto store and in a month trade it out. Life time warrantee
Got tired of burning my fingers. What's weird is it just harder to made the light come on, like the spring was getting stronger inside.
    Picked up a NOS accel at a swap meet been 3-4 years now still working.
   #370074 chrome specialties
   replaces oem  # 72023-51
 
    packrat       

[Norton Commando]

Hi packrat 56,

Thank you for the response. I tried searching the part number, 370074, in Drag Specialties and Custom Chrome, but couldn't find it.  Is there perhaps another source for this part?

Thanks,

Jason

[packrat56]

   I found
http://www.ebay.com/itm/Harley-Davidson-Accel-Brake-Stop-Light-Switch-181101-72023-51-/222187909764

[packrat56]

     Believe it or not the ex's dog ate part of the box with the accel part# on it... They make three deferent ones, flat tabs,
round and screw tabs, don't know the part numbers.
   albert 

[BKACHE]

Do you evacuate the lines and use new brake fluid?
Could moisture or crud be building up causing the failure?

[packrat56]

Do you evacuate the lines and use new brake fluid?
Could moisture or crud be building up causing the failure?

    Yes, several times, Teflon line, dot 5. I don't know what up with those switch's but they look the same as
accels , crimp, thermals, never had one leak at the crimp. I thought maybe just a bat batch I'm gonna chuck
one up in the lathe and see if I can see what's up. It might be just the O-ring not compatible with dot5 .
     packrat     

[Norton Commando]

Do you evacuate the lines and use new brake fluid?
Could moisture or crud be building up causing the failure?

Yes, I've flushed the brake lines several times.  There is not one hint of crud or water in the system.

Jason

[Evo160K]

Norton Commando,

Here's an option........disconnect and tape off the wire to the rear brake light switch.  That's what I do.  Why?  Because I want to flash my brake light while I'm slowing down to stop, so I can get the attention of cars behind me and let them know I'm stopping.  With the rear brake switch disconnected, I can apply the rear brake to slow down while flashing the brake light with the front brake lever, then I apply
both brakes to stop.  There are also times like on a downhill stop where the brake needs to remain applied, with the wire disconnected you can brake fairly hard and still flash the brake light.

[Hossamania]

Is it close to the exhaust, getting too much heat?

[Breeze]

I've had a  NAPA # SL147SB  on my Dyna for many years. Many automotive switches will work. The important things to look for:
thread size, overall length of switch unit and two blade connectors.

[gryphon]

I also got really tired of replacing sending units once a year. Was always a real PITA. I finally installed one of these a few years ago and have had no issues since. Plus they're easy to get to. http://www.ebay.com/itm/Goodridge-Brake-Light-Banjo-Bolt-With-Built-In-Switch-3-8in-24-HARLEY-DAVIDSON-/161842732968?hash=item25ae941fa8:g:afQAAOSw4HVWCxqp&vxp=mtr

[Norton Commando]

Well, I installed an Accel pressure switch; we'll see how long it lasts.

The other units I've installed do not appear to be leaking brake fluid to the contacts. Instead the failure mode appears to be the contacts becoming progressively burnt to the point where they can no longer make continuity. I arrived at this hypothesis because as time goes by, progressively greater and greater pressure is required to make the brake light work.

[04rkryder]

Have you tried a bango bolt switch

[Norton Commando]

Have you tried a bango bolt switch

No, I haven't.  But it's still a pressure switch and so it would probably meet the same fate as all the other pressure switches I've tried. 

If the Accel switch fails in short order I'm thinking about using a relay in combination with a pressure switch.  I'll use the pressure switch to send a low amperage signal to the relay, which in turn will trigger the higher amperage flow to the brake light. The pressure switch will therefore be exposed to low amperage, which should keep the contacts from burning up.

[Gary Seebon]

I had the same type problem with my 06 V-rod (street rod) with a V&H exhaust.
The radiant heat is just too much for the switch...H-D had a recall fix using a shield of sorts to reduce the radiant heat for the H-D street rod.
Use the Goodrich switch and review the amount of heat dissipated from the exhaust.
Fabricate a heat shield for the switch if required.

[voganni]

Hmm, my '97 RK has a relay in the brake light circuit. Switch works fine and has never been changed.

[Dan89flstc]

Hmm, my '97 RK has a relay in the brake light circuit. Switch works fine and has never been changed.

My `89 FLSTC doesn`t have a relay in the brake light circuit. Switch works fine and has never been changed in 28 years...

All this proves is that every once in a while, they make a good switch...

[Gary Seebon]

I'm sure the switch on different models works out fine (thanks to the engineers designing and specifying it) but....In my 2c worth it's the location location location. Any kind of switch has a temperature limit it will operate in. If you exceed the temp. limit for a length of time any switch will fail.
Again, just my 2c worth.
Ride Safe
Gary