Brake light yes, turn signal no?

[BlackBird58]

I've got a peculiar problem with the brake lights/turn signals in my '58 HT. The brake lights had stopped working, so I replaced the stop-light switch on the master cylinder and put new connectors on the wires leading to it. Now I've got brake lights, but only my right turn signal works. The left lights up but doesn't blink.

Now, here's where things get odd. Only the green wires are connected to the switch. The red and yellow ones were cut long ago. I spliced on extensions and tried every combination of connections, but the behavior of the lights didn't change - brake lights work, right turn blinks, left turn lights with no blink. Even when I disconnect the brake switch completely, the right signal works and the left one doesn't.

Does anyone have any clues? I'd really like to get this fixed before some clown T-bones me!

Thanks!!!

Mel

[JohnG]

RE: Brake light yes, turn signal no?

hi Mel

What switch are you referring to???

The "switch" on the master cylinder should only have two wires going to it. All that happens is the hydraulic pressure effectively connects the two wires together, completing a circuit and providing voltage for the brake lights (try this by hand by putting a finish nail or something in between the two leads. Do not let it touch ground). However it is not a direct path back to the brake lights.

The leads for the brake lights go through the directional switch on the steering column. There are bulbs in the rear which are used for both brakes AND directionals, leading to the need to disable the brake light on the side that a particular directional is active on. This is all done by small copper contacts in the mechanism on the steering column.

To have properly tested the lights on a car, one should really check 5 conditions:

1) brake pressure applied, no directionals on. Do all bulbs come on that are supposed to?

2) brake pressure applied, Left directional on. Does the Right brake light(s) come on?

3) brake pressure applied, Right directional on. Does the Left light(s) come on?

4)& 5) No brakes applied, directionals on.

with the comment that the bulbs involved for a '60 would be different than '58 & '59.

Assuming for the moment that no one has screwed up your wiring (this is not clear, however), you may need to get into the switch mechanism on the steering column and/or check the wiring connections on the lower part of the steering column, not to mention the directional canister (or whatever it is properly called) tucked under the dash (these are cheap in auto parts stores so you might get a fresh one for the heck of it).

Also it is a good idea to verify that you really have the correct bulbs in all sockets. Your shop or owners manual will tell you. If the wattage of a bulb is incorrect, it can keep the circuit from blinking. While you are checking the bulbs, it is good to take some kind of cleaner and clean up the sockets so the connections are good. Moisture corrodes them and 47 years has provided alot of opportunity! The bulbs are standard and can be obtained in auto parts stores although I do recall Alexander saying that foreign versions could result in non-blinking while US versions of the same bulb would blink (perhaps #1157s...)

In thinking about all this, I believe I would get a fresh canister first, install it, and then proceed to check all the bulbs (esp the side that doesn't blink) and probably put new bulbs in for the heck of it (OR swap with the side that does blink), cleaning sockets and connections as I went along. This is good to have done in any event. Attacking the switch on the column would be a last resort.

John
'58 Hardtop

[BlackBird58]

RE: Brake light yes, turn signal no?

John,

In answer to your questions:

1) brake pressure applied, no directionals on. Do all bulbs come on that are supposed to? YES

2) brake pressure applied, Left directional on. Does the Right brake light(s) come on? YES

3) brake pressure applied, Right directional on. Does the Left light(s) come on? YES

4)& 5) No brakes applied, directionals on. RIGHT BLINKS, LEFT JUST ON.

By switch, I mean the one on the master cylinder. The wiring diagram I have for the '58 TBird shows the green wires going to the stoplight switch plus a red and a yellow one that are shown going to a stoplight relay. In my car, the connectors that attach to the stoplight switch each have the one green wire, plus the cut-off stub of another wire. I unwound the wire loom that the green wires are in and found the cut-off red and yellow wires. As I said, reattaching these wires didn't change the functionality.

All the other electrical systems on the car work (dash gauges, headlights, dome light, power seat, power windows, etc) so I don't suspect major modifications to the wiring.

It certainly can't hurt for me to clean up the tail lights. If there is a problem with the bulb in the left rear signal, would the front directional not flash either? Unfortunately, the 58 shop manual doesn't describe this particular condition in the troubleshooting guide.

I'll check the connections under the dash and the flasher. Hopefully I can solve this without taking off the steering wheel.

Thanks!

Mel

[JohnG]

RE: Brake light yes, turn signal no?

hi Mel

OK...we are down to the Left directionals not flashing (blinking), yes?

So if you turn the Left flashers on, then,

a) does the front come on and not flash?
b) does the rear also come on and not flash?

(in other words, both front and rear act the same,On but no flashing?) This would be good news for the turn signal switch in the steering column (not a fun item to work on...)


IF that is the case then I would remove both bulbs and make sure they were the correct bulbs, and clean the sockets while they were out, as well as polish up the bases of the bulbs. IF the problem continues once cleaned and checked, I would try new bulbs. Also note if the green light in the dash comes on for that side. There is a #57 bulb behind the dash that should operate.

Passing those tests, I would still be inclined to put a new flasher unit in as it might be marginal; good enough for one side but not for the other. I think I paid about $1.50 or so for one.

Aside: I also have a '58 hardtop but only 2 wires going to the switch on the master cylinder...wonder what those other 2 wires are doing there...however they don't seem to play any role as you pointed out.

John

[BlackBird58]

RE: Brake light yes, turn signal no?

John,

When I turn on the left directional, the left rear lights up; the front doesn't. Is it possible that clearance in the slot in the steering wheel is keeping the turn lever from getting all the way "on" in the left side?

I looked through the Tbird-HQ catalog last night, and I saw various turn signal switch related parts (pawl, spring, etc) but not the spring itself.

I guess I'll have to start by replacing the bulbs and flasher and hope for the best. If I've got to get in the steering wheel, what exactly am I looking for to be broken?

Thanks,
Mel

[Alexander]

RE: Brake light yes, turn signal no?

One thing I have found with the Squarebird sockets is that only American-made 1157 work in the sockets. If you use ones made overseas they will not function as brake or turn signals.

Alexander
1959 Hardtop
1960 Golde Top

[BlackBird58]

RE: Brake light yes, turn signal no?

Incredible. Replacing the flasher did it. Inspired, I wanted to check if I've got functioning back-up lights. I don't. This I suspect has to do with dead bulbs. I pulled the rear left signal light cover, and I can see the back-up bulb fixture, but how do you get it out? Is it a pry-off like a hub cap?

Thanks for all your help!

Mel

[Alexander]

RE: Brake light yes, turn signal no?

The back-up light socket that is the middle of the lens assembly can be wiggled out by hand or carefully pried out with a screwdriver.

Glad you found your problem.

Alexander
1959 Hardtop
1960 Golde Top