Help! Turn signal electrical issue has me stumped!

Sorry, I'm getting a little overwhelmed, so allow me to step back for just a moment and restate the facts:

1). I'm using an electromechanical flasher made specifically for positive
ground vehicles. The flasher has a pigtail lead that must be connected to
ground...and is.
2). All signal bulbs are standard 6 volt incandescent & I recommissioned the
cowl lights to now function as front turn signal lights using the same
bulbs.
3). The signal switch unit is a 4 wire Yankee 960.
4). The signal switch is NOT GROUNDED - the flasher and lights worked
without the ground, so I didn't connect one.
5). Using a 3 brush generator with diode style cutout.
6). The turn signals work perfectly with the engine OFF. With the engine
running, he signal lights only shine as if they were running lights.

BEYOND THIS, I'M LOST!
 
The electronic flasher needs a ground to function properly. Since it is made for positive ground then it should function. It will function with led bulbs alone according to the manufacturer. Now it has to have enough power to function. A 3-brush generator that is set too low may not supply enough power while the engine is running. With no ground it definitely won't get enough power.
 
rotorwrench,
What you're saying makes sense, but again, the signals work perfectly while the engine is off. So, if I understand you correctly, I should ground the signal switch, increase the output of the generator, and use a carbon core high tension coil wire?
 
mcgarrett said:
nkaminar,
Thanks for your recommendations. From reading many of your responses to electrical questions here on the Barn it seems you have a good grasp of electrical theory and trouble shooting. Please forgive me, but I realized in my original posting that there is one more piece of information I forgot to mention. The Pilot light on the switch unit doesn't indicate when the unit is activated left or right. I just realized that I forgot to ground the turn signal unit itself, which is probably why the Pilot light on the signal unit doesn't work...Duh! :rolleyes: Best I can tell, the switch unit must be grounded and since my steering column is painted, I need to add a ground wire to accomplish the grounding. Aside from that, I can't get my head around why the signals flash properly when the car is not running, but work so well when the engine is off. Should I connect to a different power point on the car?
Click to expand...

For giggles power your turn signal directly to the battery, give it a try running
 
Try the carbon core wire from the coil to the distributor. These are cheap at any automotive store or online. The resistance keeps the wire from radiating electromagnetic energy and in theory should allow more of the energy to get to the plugs.
 
Big hammer,
My power wire is attached to the hot post on the starter - which is directly connected to the heavy battery cable. Isn't that the same as what you are suggesting?

nkaminar,
I'm going to try switching over to the carbon core high tension wire from the coil as you suggest. But something tells me that the problem has something to do with the 3 brush generator. Why else would the signals work great with the engine off and not flash when it's running???
 
When the engine is running, the ignition is drawing around 3 to 4 amps. If the generator is only puting out 2 amps then the system is in a discharge mode. When the signal system is on battery only, it will have full battery capacity to draw from. When the engine is running, the load is shared by the battery and the generator.

An RF problem will only happen when the engine is running so it may be causing interference with the electronic flasher. I've also had RF problems with certain types of shop lighting where I had to remove the vehicle from the shop to get things to work properly. You just never know where interference can come from sometimes.

I had several helicopters during my career that gave me RF problems over the years. When the operator would key up the microphone and transmit over the VHF radio, the alternator would sometimes kick off line. I moved the antennas for the VHF radios to the rear section on the tail boom to try and stop it but it would still go off line now and then during approach to an airport while talking to the tower. I ended up using a different kind of electronic alternator control unit that had a separate over voltage relay which I could mount farther away from the RF signal. This cured the problem but I could never figure out why some aircraft would have this problem and others would not. I resigned my thoughts on it to just cure the problem and go on down the victor airways. Not everything in this world is easily explained.
 
mcgarrett said:
But something tells me that the problem has something to do with the 3 brush generator. Why else would the signals work great with the engine off and not flash when it's running???
Click to expand...

The flasher unit gets nice, clean power from the battery when not running. With engine on, the ignition coil induces voltage spikes in the line, and the output of any generator commutator is pretty noisy as well. The electronic flasher may be sensitive to these power fluctuations in some way or may be sensitive to ignition radiation from the spark circuit.

This is a problem we've been trying to figure out for a long time. Works for some, others not. If you have incandescent bulbs the best remedy is to use a bi-metal thermal flasher.
 
Badpuppy,
Appreciate your comments. I'm going to ground the signal switch and try using the thermal flasher again to see if that changes things for the better. There's got to be a solution for this problem.
 
If you want to test to see if the generator is the problem, try running the engine with the fan belt off.

Electromagnetic radiation can interfere with electronic gadgets. The electronics use some very small currents in part of the circuit and the electromagnetic energy from the ignition system can generate current in these parts that overwhelm the electronics. Same reason aluminum foil sparks in a microwave oven.
 
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nkaminar,
This morning I was thinking about doing just that. Would it hurt anything if I just disconnected the output wire from the cutout? My fan belt is difficult to get off and on the front pully without a lot of struggle.
 
Just put a jumper wire from the GENERATOR OUTPUT TERMINAL to ground. This will stop the generator from working.
 
katy,
I'll do that. In the meantime, I replaced the electronic flasher for the old thermal type and grounded the switch case. The flashers work and the Pilot lamp on the switch works, but the signal bulbs HYPERFLASH way too fast! I don't suppose there's anything that can be done about that. I'm going to pick up a carbon core distributor HT wire as has been suggested earlier and try the electronic flasher unit again with the carbon high tension lead on the coil to see if it eliminates any potential RF interference and makes the flasher work properly when the engine is running.
 
You need higher watt bulbs more than likely. I'm not sure what the watt rating on the standard model A brake light bulb is but both front and rear bulbs need to be bright cp type bulbs or it won't draw enough current. Park light and regular tail light bulbs aren't bright enough.

If a bulb burns out it will hyperflash.
 
rotorwrench,
All the bulbs are working. I suspect the problem lies with the low wattage rating of the cowl lamps since they are the smallest and lowest candle power, but there is no room for larger, higher wattage bulbs due to the design of the cowl lamp and its reflector. It appears I'll need to change my original plan of using the cowl lights and add a couple of lights for the front signals that can accommodate larger, higher wattage bulbs.
 
There are conversions for 1928/29 or later cowl lamps that will fit 1157 or 1154 type two filament bulbs. The GE 1157 is a 12-volt two filament bulb and the GE 1154 is a two filament 6-volt bulb of the same type of bayonet fitment. The filament used for brake light and turn are bright and are standard wattage for the Fords that came from the factory with turn signals in the late 40s and 50s. If a person didn't care about park lights then that filament could be left unused where a park lamp in the two light headlamp would work for park lights on the front. An extra wire may fit in there if a person wanted to use the park lamp feature in the cowl lamps.

Tail lights may just get by with a standard 6-volt single element brake light bulb. So many of these things have gone to LED that I don't know if any of the old style stuff is available any more.
 
Hyperflash can be caused by wrong polarity. Got one off ebay that did that. Opened it up and found a transistor inside that activated the thermal switch. It was the wrong type for + ground, would have worked for neg. I replaced it with one from Snyder's.

The 10 CP (10W) bulbs are bright enough, I think. LED bulbs will fit behind the cowl lenses and can be very bright. So long as you have 21CP (18W) in the back you should be ok. There is also an 18W bulb that fits the cowl, G6 size. I saw it on a French site, but should be available elsewhere.
 
I have learned a lot from reading this string. I did change the coil wire to carbon core for better performance and less RF interference. You can get all of what you need to install signals at one site.

Go to this site:

https://www.ledlight.com/

Everything you need is there. I did it all with LED components because they last longer and take much less power. I also used the signal stat 900 and a 6 volt pos ground LED flasher from this site. Also if you enter Model A in the their search box, replacement LEDs for the headlights will come up. Choose warm light color if you want the original head light color rather than bright white. The site lists replacement LED bulbs for the original incandescent bulb numbers. You can change the cowl light sockets to dual filament from this site if you want so they work as signal lights and running lights. Bright LEDs will just fit. I think Snyders may also have the sockets for that. Choose red bulbs for the tail lights. Choose amber color bulbs for the cowl lights. Read the interesting info toward the bottom of the pages. I did the change and it worked great but took me a long time because I had no idea what to do. Make a plan of how you will wire it before you start. I only used the plate light from the left tail and added two original looking lights from the auto parts store attached to brackets off the bumper. I'm 80 yrs. old and had no idea what to do, so if I did it you can do it easily.

Use thermal flasher only for incandescent bulbs and use electronic flasher only for LED bulbs. Keep it simple.
 
I don't see how you can have 'hyper flash' with incandescents and a thermal 535 flasher. It should be working fine.
But I'd suggest trying higher candlepower bulbs. Maybe even adding an extra bulb or two and hiding it/them.
 
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