Brake light switch

[Merle Coggins]

Just needing to vent a little...

Yesterday on my way home from work, with the "Dodge", I stopped at a traffic light and noticed a guy running up along side my truck. "Hey, you have no brake lights.", he says. He had been following me for several miles through many stops for lights. "Really? Wow, thanks", I say. I'm only a mile from home at this point. I get home and break out the multi-meter. I have 6 volts to the brake light switch. If I touch the two wires together the brake lights work. I switch over to Ohms and connect to the two cantacts and set the meter up by the windshield. When I step on the brake I get a reading around 500 - 600 Ohms. This switch was new. (I found the receipt from Napa this morning, dated 5/29/08). I parked the truck and jumped on my motorcycle for a trip to the parts store. The guy at my local Checker was quite helpfull. He was able to find a P/N in the 'puter, but didn't stock it. He tried to match it up with something that would work, but the only brake switches they stocked were mechanical types. "OK, thanks. I'll try somewhere else."

There's an Advance down the road, but they use the same Parts America system, so I thought I"d try Auto Zone. The kid I got there was usless. They didn't list a brake light switch for my truck, but I finally got him to look one up for an early 50's Dodge car. Good number found, but no stock. "Can you look in the catalogs for something that'll work?" I soon realized that he was completely lost, not even knowing which catalog to look in. "Thanks, but you're no help!", and I start walking out. "Try a dealer", he says. "Yea, right", I'm thinking. But what have I got to loose. I'll be driving right past Wilde Dodge on my way to Adavance.

At the dealer... "By chance would you have a brake light switch for a 1950 Dodge truck?"... "chuckle... I can't even look it up. Our system only goes back to '85, and we don't have any old microfisch here."... "Well, if you can't even look it up, the chance of having one on the shelf is pretty slim. " Then while I was talking with him I found out that there was a new Napa right around the corner. I didn't even know it was there. It's about a half block past the grocery store I frequent, but I rarely go down the street that far so I didn't know it was there.

I stop at the Napa. No stock, but after a little prodding he checks stock in the local warehouse. There have one there. He also says that there's a 12 month warranty on that part. "Great, I'll have the other Napa store get it tomorrow." They will deliver it to our shop. Plus I should be able to warranty it through them easier, since that's where I got the original one.

As I said, I found the receipt this morning and gave them a call. No stock, but they have 2 at the warehouse down town. "Great, get me 2. I have the 1 as a warranty replacement, and I'll keep 1 as a spare."... "OK, you should have it by noon." Cool, I have have brake lights again before the end of the day.

During my parts store chasing last night, I also stopped at my local Farm & Fleet store. I got a general purpose push button switch just in case I needed an emergency manual back-up system. I also found a 6 volt start solenoid for a Ford 8N(?) tractor. I am thinking that maybe the Napa switch can't handle the amperage draw to light 2 brake lights? Maybe I could wire in the solenoid so that the switch doesn't have to carry the full load. But then I calculate the load. 2 - 1154 lamps at 5w/18w = 36 total watts with the brakes on. 36 watts/6 volts = 6 amps. If these switches can't handle 6 amps, they're not much of a switch. I'll have to calculate what the starter solenoid will draw. Maybe I'll go that route anyway.

So, if all goes well this afternoon I'll have functioning brake lights again. Plus I'll have a spare switch for the next time.

Thanks for listening to my rant.

Merle

[Young Ed]

Merle sounds like you just had a bad switch. I've got 2 lights on my truck and haven't had any issues with the switch. My coupe only has 1 light so far and the original switch failed the opposite of yours. The brake light would stay on and I kept ending up with a dead battery. 3 years later and my napa switch on there is still going just fine too.

[Zeke1953]

Merle,

When I replaced the entire brake system on my B4C, I did a lot of research on the issue of DOT 3 vs. DOT 5 brake fluid. One of the things I recall reading was that someone reported a high incidence of hydraulic brake switch failures with DOT 5. Don't know if this is true or even if it applies to you, but thought I'd pass it along anyway.

Zeke

[Merle Coggins]

Thanks Zeke,

That's interesting, but I'm using DOT3.

Going by what Ed says, I'll throw in a new switch, when it arrives, and see what happens. If this one craps out I'll have a spare in the glove box.

Merle

[tctrkca1]

I have changed five or six switches due to the fluid being changed.It is a rubber diaphragm and a spring.Due to fail eventually but usually last many years.Jim

[greg g]

I'm running 3 6 V 55 watt Halogens as stop lamps, no problems with my switch.

You motorcycle probably had a hydralic switch. H/D dealers usually have them in stock, and they are used on virtually all ATV's.

[Merle Coggins]

My motorcycle doesn't have pressure switches for the brake lights, but it's good to know where a guy might source one on the road.

Thanks,

Merle

[MBF]

Merle-the switches do go bad. I've replaced the one in my '36 plymouth, and 52 1 ton a couple of times since I've owned them. You can tell when they're starting to fail as it takes a harder push on the pedal to activate the switch. When I put on the replacements, the brakelights come on almost before you can feel the brakes being applied. I've never taken a defective switch apart, but I would imagine its due to the gumming up of the plunger portion of the switch. Mike

[norrism1]

Just a suggestion, put a micro switch with the roller on the arm under the dash to work off the brake peddle. Sheet metal bracket with adjustment slots would be a lot easier to make and if switch went bad you could go to local electronics store to replace. Leave original switch in MC for looks if you wanted too!

[Vintrader]

Merle, I replaced mine a NAPA a few years back and it has held up pretty well. At 8 bucks I think it was and 10 min labor, I can replace it every few years if I need to. Dutch