The Stovebolt Site Forums The Shop Area The Electrical Bay Brakelights work, Taillights dont

I guess it could be worse.....

Recently converted from 6 to 12 v.

Just overhauled my rear Stopray's (cleaning out the rust, rewired the sockets, etc.) First tried
the brakes and BOY ! they're bright. Tried the tail lights and nothing !!. Disconnected the
wires to the tail lights and checked the wires for life with the headlight switch turned on.
Strong 12 volts.

Re-connected the taillights, inserted the bulbs, nothing.......

Is it possible that when installing the bulbs that so much force is being applied to the wire
conductor underneath the bulb that it's somehow pressing the wire to the light box itself
causing a short ?

Isn't it odd that both tail lights have identical symptoms ?? And yet both brake lights are
brighter than the moon on a clear night ???

I'm now questioning if the problem is really in the back ? Can it be that the problem is maybe
somewhere upfront though is not apparent when you simply run a volt meter at the back ?

Any words of wisdom would be greatly appreciated....

Are the tail lights seperate from the brake lights. If so it could be a bad ground.

(Sorry there not really words of wisdom, just taking a shot)

Which bulb setup do you have? Two sockets per lamp, as original? Or dual element sockets? If you switched from the two socket setup did you install a dual element socket? The bayonets are staggered on the dual socket. 1157 bulbs in the dual element sockets? Installed correctly? You can put them in backwards, but it takes a lot of force.

Yes, it's the two socket per lamp setup. Upper being brake and lower being tail. In both left and right, I can measure 12 volts with a volt meter touching the wire at the bottom of socket and grounding nearby. But if I put a bulb in......nada.....nobody home, etc.

At this point I'm guessing that maybe when the bulbs are in place that so much pressure is being placed on the hot lead that somehow it's grounding itself against the socket ?

:confused:

Cmayna,
The hot lead grounding itself against the socket would cause a dead short and blow the taillight fuse.
The bulb does ground itself thru the socket. Power enters the bulb thru the base, goes to filamint and exits out the brass section of bulb. The brass section is touching the socket itself, which is grounded. IF you have 12 volts in base of socket w/o bulb, you either have a bad bulb or ground.
Try taking a test light to the terminal in the bottom of the socket and grounding it in differnt places, including the socket or light housing. If the test lite works with a different grounc, try running a new ground.

Curly,
Thanks for the education and suggestion. I'll give it a try as soon as this !@#$ rain stops. I don't understand how it can be raining here in sunny Calif. Suppose to be bikini weather

One other possibility is the base of the bulb is not making contact with the conductor. There has been some problems with this on the newer replacement bulbs, they are no longer made in the USA.

We are getting your clouds, but it is not supposed to rain. I hope it doesnt, this is the weekend of the big carshow here, MIdnight at the Oasis. Expecting 800 cars. Got my 59 cad cleaned up adn ready to go. My 59 P.U.is in the process of P.S. conversion

TAIL LIGHTS WORK !!!!!

you'd never believe how this tale ends............ Though I was getting 12 volts through the sockets via volt meter, test lights would not light up.... So I started from the back and worked forward with my pointed probe test light looking for where I would finally get some light. I got nowhere under the truck. Tested the taillight terminal on the dash switch and it was working fine.

We're getting close now......Went to the engine compartment and tested under the fuse box, nothing....(I had previously LOOKED at the fuse which seemed fine). Tested above the fuse box and whola, light.

Yes, though a fuse may LOOK fine, one should test anyway just to make sure there is power after the fuse. Replaced it and "Houston,,,,,we have liftoff!!" This would have saved me hours of searching and light fixture cleaning, regrounding, etc.

Thanks to all who contributed to this thread. I did learn a lot about good grounding, etc.
Craig

Wow and then you come here and admit it? Brave man...

My next project is fixing the attempt the PO made at upgrading from 6 to 12v. My truck is defenitely not charging. But, I decided to wait until after our show. I would hate to start the project and get stuck not able to take the truck. Right now my batterycharger is my friend.