C1 Brake Light Mystery

[Philip P.]

Re: C1 Brake Light Mystery

Hows this it should be what you have it is like my 1960 this is from the passenger car servce manual
Phil
fuse panel 2.jpg

[David B.]

Re: C1 Brake Light Mystery

Phil, that's perfect! Thank you.

I'll explain what I did tomorrow, when I have more time. Excellent picture!

What was your source for that? I couldn't find one on the Web.

Dave

[Philip P.]

Re: C1 Brake Light Mystery

Page 9-53 1958 Chevrolet Passenger Car Shop Manual

[David B.]

Re: C1 Brake Light Mystery

I should get a Chevy Passenger Car Shop Manual, Phil. There are some things not covered in my 'Vette manuals.

So, here's my stupid, weird brake light-fix story. The stupid part is that I started looking for the problem on the wrong fuse. If you look at Phil's excellent fuse block picture, you'll see the word "Brake" under the third fuse down on the the right side. Stupid me thought that that fuse controlled the brake lights. That was one of the only readable words on my fuse block. So, I agonized about why my new brake lights wouldn't work when the fuse was okay and I had a new brake light switch. Little did I know that the top fuse, labeled "Tail LPS," which I couldn't read on my block, was the right one. Naturally, I didn't check to see if the fuse was blown, which it was. Stupid.

Anyway, I eventually found out that the top fuse was the right one for brake lights. So, I checked it and found that it was blown. My old faulty brake light switch must have shorted out (at least that's my theory) and blown the fuse. Anyway, I replaced the fuse, thinking that that was the end of my agonies. Wrong. Now here comes the weird part.

You may recall that back up in my Post #6, I said:

>>I have the new switch dangling down and not fastened to the switch bracket. This effects a closed circuit, as if the brakes were applied.<<

Even with a new fuse and a new switch, my brake lights wouldn't work. So, I went on a wild goose chase trying to find out why power wasn't getting to the switch (I'm leaving out telling you of my hours of maddening, back-twisting searching under the dash). Finally, my 65-year-old back said, "Enough bending me over backwards!" So, I decided to bag it for the night and head back here to the forum to ask more dumb questions. During my clean-up, I decided to mount the new brake light switch in the bracket, just to get it out of the way. After I did that, I said to myself, "Hey, just for whoops, I'm gonna connect the battery and see what happens."

What happened was that my brake lights came on when I pressed the brake pedal. They worked!

I sat there and asked myself, "Why are they working now?" The only thing I changed was mounting the brake light switch into its bracket. This tells me (inside my pea brain) that mounting the switch in the bracket created a ground that allowed the power to flow through the switch to the brake lights.

My question is: How can that be? The switch body is plastic and the two nuts that secure/adjust it aren't in the circuit.

Keep in mind, guys, my capacity for dumbness. I just can't figure out why mounting that switch (after I replaced the fuse) fixed my problem.

Anyway, thanks to everyone here for your excellent and timely responses. Y'all are the best!

Dave

[Philip P.]

Re: C1 Brake Light Mystery

Well to answer your question it does not work that way, my guess, this will cause problems, the contact(s) on the switch may have shorted to the steering mount that would explain a blown fuse.
THe manuals can be found periodically on Ebay not real expensive but there is a lot of material that is not covered in the ST-12. There is a web site http://chevy.oldcarmanualproject.com/, that has some manuals on-line. Disclaimer I do support this site.
Glad you are back up an running, I will not complain getting under the dash as I am younger at 62.
Phil

[John H.]

Re: C1 Brake Light Mystery

I sat there and asked myself, "Why are they working now?" The only thing I changed was mounting the brake light switch into its bracket. This tells me (inside my pea brain) that mounting the switch in the bracket created a ground that allowed the power to flow through the switch to the brake lights.

My question is: How can that be? The switch body is plastic and the two nuts that secure/adjust it aren't in the circuit.
Dave

Dave -

It can't. There's no ground associated with the switch itself. Power goes in one side of the switch, and flows out the other side (when the pedal is depressed) to the turn signal switch in the steering column (which controls whether both or only one brake light comes on, depending on the position of the turn signal lever), and from there to the "bright" filament in the brake light bulb(s), and from there to ground at the bulb socket. Something you touched/moved/pulled when you mounted the switch caused them to work.

[David B.]

Re: C1 Brake Light Mystery

>>Something you touched/moved/pulled when you mounted the switch caused them to work<<

This is the story of my mechanical life, John. Half the time I don't know what it was I did that fixed a problem. It's frustrating, but at the same time fun, because now I can drive my '58 and not worry about someone behind me talking on their cell phone (or, heaven forbid, texting) and not noticing the rapidly closing distance because I had no stop lights. Let's hope that regardless of what they're doing, they'll see me stopping.

Thanks, John, and thanks to all the others here who graciously offered their thoughts. See you all next problem!

Dave