My 1937 Ruby has SF40 trafficators which I am trying to recommission. When power is applied the arm will not lift, although the light goes on. To check that the problem is not related to poor connections in the wiring system, I have removed the trafficator and connected it directly to the car battery with short wires.
When I try to raise the arm manually, considerable force is needed to move it through the first few degrees. Then there is a click from the mechanism and the arm jumps to the correct upright position with considerable alacrity and stays there until power is removed. It then drops to the correct down position.
Does anyone know whether there is something in the mechanism that I could fix to get the arm to lift from the rest position?
07-08-2021, 12:03 PM (This post was last modified: 07-08-2021, 07:47 PM by Colin Morgan.)
Hi,
The mechanism is designed to lock shut when the trafficator is down. This keeps it vertically in place when not in use and stops it swinging out on corners. When power is applied the lock should come off first - a shaped piece at the top moves down and this releases the arm so that it can rise. The bit that moves first can be seen if you look at the very top of the mechanism. It can be released by pressing down in the centre (of the very top bit of the mechanism) with a screwdriver or similar when power is not being applied. The lock is providing the resistance you can feel and it shouldn't be forced. If this bit is sticking, then cleaning and lubrication should improve matters.
I may still have a broken trafficator with a working coil, but it's highly likely that a little penetrating oil will clean yours up.
You can operate the lever from the top if you push down on the moving part inside the coil. That releases the lock and allows you to lift the lever fully.
Did loads of these on A35s many moons ago... if you are unsure about where to push, post a picture from the top and if you can't make it work, I will go and dig out the bit to check it's 6v.
Graham, It might be worth removing the pivot pin so you can slide the plunger out of the centre of the coil. I found mine to be gummed up with old grease and metal swarf; I cleaned it out with a rattle can of brake cleaner, lubricated everything with light oil and it made a huge difference.
I lubricated the mechanism as part of my testing, but it didn't make any difference. Also as part of my testing, I found the part at the top, which, when pressed in with a screwdriver, allows the arm to rise. I guess this is the locking mechanism. But the lock doesn't seem to release the arm when power is applied, although it moves easily with screwdriver pressure, with or without power applied.
Is there anything further that people could suggest?
I already have flashing indicator lights, but thought to restore the trafficators because friends and family keep asking why they don't work. It is one of the cute aspects of these old vehicles.
07-08-2021, 10:26 PM (This post was last modified: 08-08-2021, 10:56 AM by Colin Morgan.)
Yes, people like to see the trafficators working - I can see them react and point in the mirror.
If they react strongly to 6v being applied there cannot be much wrong with them. On mine there is a tiny spring that helps to pull down the locking mechanism - can you see that on yours? Otherwise, if they move freely and are set up in the car with a good supply and earth and don't foul the body, they should work. But you say they stick when closed - if it is not the locking mechanism can you see what it is that is holding the arm? Are they both the same?
The trafficator has SF40 stamped on the side of the casing.
This may sound strange, but I have the locking mechanism releasing correctly when I hold the trafficator vertical as on the car. I had been testing the trafficator horizontal when the locking mechanism was not releasing. However, when the trafficator is vertical, the arm will not reach horizontal without some help. Then, it will not drop completely down. There must be friction somewhere that I have to eliminate.
The plunger has been removed completely from the coil and all gunk removed, then replaced with a light oiling. So that is not the cause of the friction. I will have to continue to play around with it some more.
Thanks for taking the time to try to help.
By the way, I read that one person thought that the plunger should be coated with graphite powder instead of oil lubrication. Had you heard of that?
Yes - sorry SF40 is right, the later more triangular ones are SF80.
The driving force for the plunger that pulls up the arm is from the magnetism generated by the current passing through the coil windings. If the insulation on the copper wire is imperfect and not doing its job properly any more then the current can take a short cut through the coil and the force applied to the plunger will be reduced. One of the trafficators I have here has been home rewound - looks scruffy but works.
