Irritatin' Brake Light

Its the left one, figures. No workie, ever. Turn signals, tail lights, both sides work fine. Right brake light works as it should. This was not always the case, its taken more than a few manhours to get the thing to this point.
Brake light switch good. Working turn signals tell me the grounds, bulbs, and wiring are good, to both sides. As I understand it, the flashing turn signals are nothing more that the brake light filimanent turning off and on. So if your flasher works, and you've got a good brake light switch and a good fuse, your brake lights should work. Do I have flawed logic here? (wouldn't be the first time)

I've pulled apart the turn signal switch (sparton, original) cleaned and lubed until the cows come home. Took the pyramid connector apart, sprayed with pb blaster, followed by contact cleaner. Still no left brake light.
Fuse good, I'm stumped.

The only thing I can think of is to go back into the turn signal switch, and REALLY take it apart. By that I mean pry the little switch at the bottom of the thing where all the wires go apart, and see if I can find something wrong there. I'm hesitant to do that, because it is obviously not meant to be taken apart, and 9000 springs and ball bearings are probably gonna fly out, even if I can figure out how to disassemble the little thing.

Anybody have any other ideas before I get into brain surgery here?

 

Try it just like he says if that works we can make the one out of the DJ work.

 

Easier than swapping the wires would be to put a test light on the turn signal wire. If it works, the problem is in the socket (unlikely) if it doesn't it's either in the switch or the wire coming from the switch.

 

Don't think the socket can be the problem since the turn signal and brake share the same filament in the bulb. I would more likely think it is in the turn signal switch itself, that is the place where the two sides split.

 

Agreed, it has to be in the turn signal.
That sucks that you have to tear it down again.
You might try doing some more testing inside the switch. Contacts and such.
The fact that the turn signals work and the other brake works says that it must be in the switch.

 

I think its the turn signal switch also. Went over to the Gasman's place today and picked up a switch out of a postal that we have been slowly using parts from. Unfortunately, trying to figure the precise year of the postal has turned out to be difficult. It has a different year of manufacture on each of 3 old registrations in the glovebox. The Post Office meets the DMV, a truly amazing example of government compitence and efficiency.

In any event, the wires in the 75 match the color chart in my chilton's. But I've no clue for the postal (rumored to be anything from 70,71,72, maybe even 73. Of course, the switch was probably replaced at least once in its lifetime, just to add to the fun.

Wire colors on the postal are red, blue, brown, white, yellow, and black. It has a single plug, with red, blue, black, and yellow being a female bayonet, and brown and white exposed male, all on the same rectangular shaped plug. I need to figure out how to match up the wires so I can rewire to my pyramid plug.

This whole question might better have been asked on the early forum, but it looks like most folks wander the whole site, just like me. So I'll give it a shot here first...anybody have any idea what color does what on the postal?

 

A quick update for some poor devil with the same problem in the future.
Search is your friend. Found this
http://www.jeep-trucks.com/WOJP/Electrical/Spartan.html
solved all my problems. Has photos of a COMPLETE teardown of a sparton switch. Unbelieveable. Kudos to the guy who posted it. It really should be a permanent part of the tech section. Not to be "shoulding" on anybody here, but it is an awesome writeup...thanks again for your help, everybody.

 

Glad you were able to fix it.