The Stovebolt Site Forums The Shop Area The Electrical Bay brake / headlight problems

hello guys, i hope you have the answer i need.

is it possible for the tail / brake lights to be acting up because of a faulty head light switch ?

i have a 57 3100. new tail light housings at least 2 years old, before i bought it. in the past i have had brake and tail light problems. sometimes they work, sometimes they dont, either both tail and brake lights, or just one or the other.
it has been fine for about a year now, but tonight they were acting up again. i had only one brake light and the opposite tail light, so i fiddle with it, and then had no tail lights. kept messing with it, turning the headlights on and off, pressing the brake pedal, etc, then i had both brake lights, but then all of a sudden had no headlights or tail lights, the headlights have always worked before, never letting me down.

thankfully the previous owner had a new headlight switch that came with the truck, and i was so mad trying to get the old one out to look at it, i broke it. so hopefully tomorrow i will install the new headlight switch and see what happens.

i did notice on both new and old switch, there are connections for head lamp, tail and brakes, so i do assume all that stuff runs through the headlight switch ?

thanks for the help guys.

leonard

oh yea, i forgot to mention,
since the drive train and fuse block are out of a 1980 1/2 ton truck, the headlight switch might be from a 1980 truck also.

thanks

leonard

The headlight and tail light circuits will run through the headlight switch, but there should be a separate circuit for the brake lights. The most likely cause for intermittent operation of lights in general is bad grounds. There must be a clear path back to the battery for every circuit, and when one ground path is blocked by high resistance the circuit will look for another way to complete itself. Sometimes that turns another light off by the voltage looking for a path to ground through the filament of another bulb. It's not uncommon for one bad ground path to cause another light to go out when the brakes are applied, etc.

Start by cleaning all the bulb bases and sockets, and then make sure the bed and front fenders have good grounds back to the frame and/or engine. Good luck!
Jerry

very cool jerry.
so, i can actually run a ground strap from the bed and front fenders to the frame ? easy enough.
i did some looking on a few websites, and the head light switch is for 1957. i should have taken a pic of it, but where the wires connect they say, tail, brake, and head lamp, i think.. its in the truck now and dark out there. LOL.
first i will try the switch, and then if need be i will run separate ground straps from the bad and front fenders.
thanks a bunch.

leonard

Look a little closer, and the wires are probably labeled, Tail, Park, and Headlamp. The tail lights come on in both Park and Headlight positions, while the park lamps usually don't burn with the headlights on. That's the way things were done in 57, now a lot of vehicles run park lights anytime the engine is running, and/or they keep the headlights on at a reduced level during daytime running.
Jerry

Hey there Leonard;
Your switch probably does have a "brake light" terminal on it (the '55's do) and it is the point where the 12V is taken to power the brake light switch, so even though that terminal is not "switched", it's there to provide the feed.

Your problem sounds like a grounding issue to me too.

hot rod and waldo, thanks so much for the help.
my switch actually does say, "tail, park, head lamp". nothing on it that says brake.
after a clean start today after work, the reason the head lights were not working is because the fuse was blown. so i changed the switch for no real reason, but i had it anyway, so oh well. my stupid mistake for not checking the fuses.

i then ran a separate ground wire from the frame to the tail light housing bracket where it bolts to the rear bottom of the fenders. still had problems.

yesterday i worked on it for 2 1/2 hours, and today for another 4 1/2 hours, and still dont have it. it is driving me crazy.
everything, brake, tail and blinker lights, all seem to do something different at different times. most times its either no brake lights at all, or just one, or only one tail light. then sometimes when only hitting the brakes, it will light both filaments in the 1157 bulb.
when i ran out of sunlight, i decided to go a different route.
i unplugged the switched white wire from the under floor board brake light switch, ran that wire to a virgin socket connector with an 1156 bulb, and kept all the other wiring the same to run the tail and blinker lights.
so far it has worked, so tomorrow i will drill a second hole in the back of both light housing and install the 1156 socket in there that will be for only the brake lights.

i know it aint the right way to fix it, but i am getting to the end of my patience. if, after all this it still acts up sporadically, then i dont know what i will do.
other than finding the blinker, tail and brake wires, and bypassing the originals and splicing into them near the steering column and running new wires all the way to the back, thats all i can think of. its very frustrating to put this many hours into a simple thing like tail and brake lights..

i will let you all know how tomorrow goes.

thanks again.

leonard

"then sometimes when only hitting the brakes, it will light both filaments in the 1157 bulb."

Symptom of bad grounds. You say you grounded the light housing to the frame. Does the frame have a dedicated ground? If not, you should add one. If it does, unbolt it and clean it. You are wasting your time running new wires to it if it doesn't have a return path.

thanks much cletis.
after sleeping and thinking, and re-reading all these tips, i did forget to check the ground i have that comes from the battery to the frame. it very well could be rusty and not making a good ground.
thankfully i didnt drill a second hole in the tail light housing for the second bulb i was gonna run for just the brake lights, because, like you said, it might work now, but soon could not, because of the bad ground.
that has to be it. most times i get frustrated and dont look at the big picture, even when someone is telling me.
i will check back in later this afternoon when i am done messing with it.
thanks so much to all of you.

leonard

well guys, i have given up.

went out there today and found my frame ground from the battery to be rusty. easy enough fix, got out the 4 inch angle grinder and sanded the area nice and clean. reconnect the ground and everything worked.
went the extra mile and installed a separate ground strap from the tail light housing directly to the frame, on both sides.

put all the tools away and wax the back of the truck to get rid of all the finger prints, put the wax away, and then the brake lights dont work. try the running lights twice, and once they both worked and then next time only one worked. hit the brakes and nothing. i always have blinkers, and mostly running lights, but the brake lights a the problem.

with a friend pressing the brake pedal i see the factory switch dont disengage all the way, so with his still pressing on the pedal i pull the switch all the way as far as it will go and still no brake lights. doing this same procedure once i did have both brake lights and once i had only one. so although i will order a new brake light switch, i dont see, how, if it is malfunctioning, how it could once make only one brake light come on. i would think it would either be all or nothing.

so i will order a new brake light switch and maybe a new set of tail light housing, although mine are fairly new with no corrosion, and go from there.
after that, i dont know what else to do....
i hate electrical problems.

i know now 100% that i do have good grounds though...

thanks much.

do you guys knwo where i can get a good American made set of tail light housings for my 57 ?

leonard

i think i have narrowed it down to the brake switch and faulty 1157 connectors at the chinese made housings. the connectors are total garbage. wiggle it and lights go on and off.
i will order a new switch from classic parts and look at my local parts stores for a better type bulb connector and mate them into my housings.
after that, if i still have problems, the truck is for sale. LOL.

leonard