The Stovebolt Site Forums The Shop Area The Electrical Bay Brake light problem- I'm stumped

I've got an issue with my left brake and signal light as of last night, but I've got a weird glitch. My drivers side signal/stop/tail lights all work fine. My passenger tail/parking light works fine. But last night when I pulled into my parking spot in front of our house (which is on a hill, nose down), I got out and my brake pedal stuck in the down position as it sometimes does due to a badly cut hole in the repair kick board metal by a PO. It almost always releases when I close the door, or manually 'toe it up'. But before I closed my door, I decided to go back and check the lights to see if all was good. My passenger brake light was not on. I reached in the cab and turned on that signal light, but it was dead too. (Didn't check the running lights, since it was cold and dark, but they were ok today when I put the meter on them. Anyway, I tested the lines today, figuring I had a loose or corroded ground. I had power to the tail lamp, but not the brake and signal bulb. When I checked the wiring at the back axle area, I found one iffy connection on the wire feeding the problem bulb. I had forgotten to put a crimper and shrink tube on (still had a wire nut and tape), from when I had a ground problem last spring. I replaced the whole housing and added a flex chrome wire carrier at that time- before I figured out I had a bad ground!
After installing the new connection fitting today, I tested hot for both signal AND brake at the bulb seat. Great!!, I said. Then I put what appeared to be the good bulb back in, and tried the signal light. Zilch. Then I applied my patent-pending delayed-reaction-brake's Wonder Pedal and it didn't work either, after just getting good readings on both actions. At this point I thought to myself, "at least I won't be out in an ice storm trying to put a new fitting on that wire that I didn't finish!", and proceeded to get a new bulb out of the glove compartment. BTW, my brake and signal bulbs in back are 23w 12v. The signal light is working fine, but the brake light is not coming on. Now I'm puzzled. It was working fine just a day or so ago when my wife was behind me, and it's been good since last spring. What the heck could be going on here? These are single contact receptacles, they're clean, I can't find any bare spots in the circuit, and this is a 6 moth old housing (and the ground is good, not corroded) What's everybody think about this? What am I missing here? Thanks in advance, and sorry for the long story. Lee Butcher

Ummm- ok, after a drive to the park, it's working. Go figure.

Had the same problem a year or two ago and believe it or not it was in the turning light switch that made all that rear turn signal light switch go hay wire. Take and have someone at the rear of your truck while you exercise your brakes turn signals etc. etc....

It's been my experience that most light problems are caused by bad grounds. In many cases it is the connection between the light housing and the body. Also between the body and the frame. Any amount of rust between the any of the contact areas can cause an intermittent problem.
Fred

Fred's advice/experience is excellent.

I'd like to add that bad grounds could be caused by rust/corrosion and could be caused by too-good a paint job. The screws have to touch clean/conductive metal (giving continuity to an electrical "ground" -- ultimately to the frame/battery-ground cable).

assuming as you stated that all grounds and wiring is good, if the turn signal and brake light are the same element, and the turn signal works fine but brake is intermittent, as ol' 55 said, turn signal switch may very well be the issue, especially if it is original style (original or new replacement OEM style).

The old style turn signal switches don't always return to center properly and can cause either one or sometimes both brake contacts inside to not make contact and you get a brake light out. I added a lair if indicator lights inside on my 58 that are tied to the rear turn signals/brake light wires so I can tell if one is not on.

Right. I was really kind of surprised when I opened mine up the first time, to see that there was so much going on in there. I even had printed out the schematics to it, but didn't expect it to be that many points of contact, I guess. I had never realized that the signal and brake were both on the same circuit, and that they had to tie in somewhere. Per my problem the other day, it was after I had upgraded the connection till I was getting any power at the lamp sockets, and both were dead before that. What got me was how could I get light with the signal and not with the brake when both were reading hot? I figured, "well, the bulb must be bad", and put in a new one, but then I realized the bulb is a single element. WTH?? Maybe... I don't know. Then it starts working all by itself. Which is great, but it's my daily driver and I don't want the cops pulling me over if I can help it. I do try to back up to the cafe's window down the street and get a visual. It just makes me tense having to wonder if I'm legal at any given moment.

Thanks for the replies, fellas. BTW, what exactly did the original signal switches look like? And, were they mandatory on '51's? I thought they just came with the single tail light set up??

Technically illiterate as I am, I wiped out my replies to Tim and Fred, but, when I had to chase down my problem last year, I finally found the bad ground in the last place I looked, and the one place I was convinced couldn't be the problem. After going through the wiring, signal switch, fuses, brake switch, bulbs, etc, I found that the upper (away) side of the bar in the lamp receptacle assembly. I ran my frame to housing ground wire to the screw that retains that assembly to the top/inside of the chrome housing. I know now that that screw lets water enter the housing there, and it corroded the light plate and the housing inner wall. What got me there was that I looked at it, and the "zinc coating" on the flat bar that screws to the inside top of the housing was clean and corroded. But when I took it off, it was rusted on the back, badly. Zinc coated or not, all it takes on most of the stuff that comes out today is for a screw to turn next to it, and it's downhill from there. Did I mention that this was a 6 month old unit? I had called CP at 4 months to tell them the chrome body was rusting before that. I sure miss the real plating jobs and steel quality of the past. Anyway, thanks for all the suggestions and ideas. I really do appreciate it. Lee

Showme,
Maybe an answer to a couple of your questions; turn signals were an option for the 56 that I am aware of, so they were probably an option on your 51 also. My 56 came with just one light on the left hand side at the rear and you provided the arm for signalling a turn. And yes, the tail lights will need a two filament bulb to work as both tail lights (one circuit), and brake/turn signal (the other circuit).
Another Lee.

The first year that GMC/Chevrolet-trucks had a Regular Production Option turn-signal was 1954.

Dual-filament front parking-lamp "fixtures" were included, and, for pickup trucks, a rear lamp/bracket was included.

For Panel Body trucks, two rear side "bullet" lamps were included.

The turn-signal mechanism was made to fit into the steering column (using many of the parts used in 1953-55 first-style Corvettes).

Prior to 1954, a GM accessory turn-signal kit included clamp-to steering-column turn-signal mechanism and top-of-front fender signal lamps were provided. I do not know what lamps were provided/used for the rear (Brad and others might have illustrations)?

1929 - 1957 Chevrolet Master Parts & Accessories Catalog
Directional Signal Assembly scroll down
Group # 6.512 Cover Assembly
53-54 Passenger car
53-57 Corvette
55-56 Commercial Utility Part # 5942429 >Also used on 1954 trucks but not listed in Master Parts & Accessories Catalog.
All cups were the same as this 1954 Panel Directional Signal Assembly
Just a different color. ivory, silver. black for truck
Attached photo is a 1954 Chevrolet Panel truck rear side "bullet" lamp. (drivers side)

xfiles

So what I'm seeing is that there are no "built in" signal lights on trucks before '54 then. The old strap on is what's in mine, and it looks more age appropriate than some of the chrome universal types I've seen. Still works good, but who knows when it was actually installed. My tail lights and brackets are definitely newer additions, as they are both chrome and look like something sold at CP, LMC or the others. My first '51 had add on front signal lights below the headlights, but from what I can tell of my only picture of that area of the truck, it had the original 'in-grill' blinkers, too, at one time. http://pic20.picturetrail.com/VOL1373/13685773/24611517/413696793.jpg

Hey, where's page 258 in that manual??

It really is not a manual it is a "Chevrolet Master Parts & Accessories Catalog" and page 258 is blank therefore was not scanned. You can check out the Blank page on GM Parts Wiki HERE
GM Parts Wiki has multiple Parts & Accessories Catalogs HERE (sometimes the website is slow)

Here is another Ilustration of the steering column parts. From http://chevy.oldcarmanualproject.com
One thing I noticed is the switch lever knob on the end of the signal lever was changed on 1955 cars & 2nd series trucks.
The knob was usually the same color as the cup.
The attached picture is an original 1954 Chevrolet panel truck lever with a black knob.
It came with a threaded spacer rather than a nut.
Corvette knobs were white. Pictures
This is a Picture of what is a 55 2nd series knob looks like.
It says its for 1954-59, but it should say 1955 2nd series to 59.

xfiles

Thanks, jorb! I saw that the page was from a link, so I was just joking (although I'm wondering what I'm missing there). And thanks for the link to the parts catalog, too. I've eyed those for quite a while, and didn't know if it would be worth getting. I should know better, though. I have the parts catalog to my '03 Indian Chief, and it's a big help. I'll be getting a parts catalog for a '51 now, for sure. I also now realize that when I see the parts for the signal light column switch, that it's all under later years than mine, so that answers that question- mine never had it. I thought maybe it had possibly gone bad and they just replaced it with a strap on.
But can earlier models add that? Or is that not possible without major re-work? Anyway, thanks, and here's a few pics of what I've got. Like I said before, I've got to pull it apart and reconnect the switch indicator light wire, but I've gotten so use to turning it on and off by habit, I don't even look for the lights there anymore. But I AM getting a parts catalog, if for nothing else than to give me good views that the factory and shop manuals don't give you. http://pic20.picturetrail.com/VOL1373/13685773/24611517/413699336.jpg , http://pic20.picturetrail.com/VOL1373/13685773/24611517/413699335.jpg