Help! Turn signal electrical issue has me stumped!

M

mcgarrett

Well-known member
Just installed turn signals on my '30 Model A; still 6 volt system/positive ground. Using a vintage Yankee 960 turn signal unit along with a 6 volt/ positive ground 3 prong flasher unit I got online. It worked so well with the 6 volt/pos. ground system on my'40 Ford, I got another one for this car. The turn signals work perfectly with the engine OFF. BUT...they light up, and DO NOT flash with the engine running!?!?:confused: The flasher is unique in that it is designed to be used with a positive ground system. The photo shows a ground wire coming from the flasher unit to ground. I wired it up according to the instructions I found online. Any ideas why it's not working properly would be GREATLY appreciated.
 
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Forgot the photos...
 

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So when the engine is off it is running on the 6v battery.
When the engine is running it is working from the generator.
How many volts is the generator putting out?
 
Curtis,
Don't know the answer to your question, but I'll check it tomorrow. I didn't think it would make a difference. My '40 Ford is using the same setup with no problems and it has a 6 volt generator too. Know any tricks I should try?
 
1. Measure the voltage at the terminal on the firewall when the engine is running at a slow idle and at a fast idle.

2. Make sure everything is hooked up correctly by measuring the voltage at the socket, engine does not have to be running.

3. The instructions say that there can be a problem when the engine is running if there is an equalization problem. I don't know what they mean but it could be that they are referring to some bulbs being higher watt that others. Check to see that all bulbs are working and have the same rating and that there is no problem with the sockets.

4. If you cannot find the problem, call the people who make the flasher.
 
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?
 
Those e-flashers can cause strange problems on some cars. Use a standard thermal flasher from Snyder's unless you're running LEDs, in which case add ballast resistors to it.
I used that exact same flasher in my A and had no problems, but I had a fancy setup using relays and stuff.

Many signal units come with 12V bulbs and don't light at 6V. #44 or #51 are common 6V bulbs.
 
We need to know a few more things here. Are the lights involved LED or incandescent?. Does the car have a 3-brush generator as OEM or does it have an alternator conversion? If it has a 3 brush generator, does it have a diode rectifier that looks like a cut out or an original type electromechanical cut out relay?

When looking at the photos in post #2, it appears to have a lot of paint where the signal stat is grounded. Is this some form of coating or is this a fiberglass material? I cant tell whether it has got a solid ground path or not?

A 1940 Ford would have a 2-brush generator with an actual 3-pole generator control unit that has a cut out, a current limiter, and a voltage regulator. The 3-brush generator has no voltage regulator since the battery will self regulate the system voltage. The third brush has to be adjusted for current output depending on several load factors so it would have to have enough output to carry what ever load is on the electrical system at any given time.
 
rotorwrench,

Answers to your questions:
- All bulbs are incandescent, no led's
- 3 brush generator
- Diode type cutout

Is there a work around to make the flasher work while the engine is running? I'll admit I don't understand what makes the difference, but electrical trouble shooting isn't my best subject. In fact, my electric shop teacher in Jr. High was... wait for it...Mr. Short! (no kidding! :D)
 
You don't really need an electronic flasher with regular incandescent bulbs. The bi-metallic flashers with the pilot terminal should still be available for 6-volt systems. They don't need a ground since all they have is the bi-metallic strip to function the switch. Power for the flasher really should come from the generator terminal but it may work if connected to the battery. Most loads are connected on the generator side of the ammeter so that they will register on the ammeter correctly. At night is when a person wishes for LEDs. With lights on and turn signals functioning, the load on the generator is pretty heavy. It would need the 3rd brush adjusted a good bit for peak amp output.

The model A system was originally designed for two headlights and one tail light but we tend to add more to them in the modern era to keep us safer on the road. Turn signals didn't show up till after the war as an optional accessory. They stayed that way till the late 40s and early 50s. The Mercury cars got turn signals before the Ford cars did.

With an original ammeter, a person can see how many amps the generator is putting out. For lights on operation a person is going to need more than 4 or 5 amps output. During the daytime hours, the ignition will be the largest constant draw so it will draw 3 to 4-amps. This will show just a bit of charge while the car is running with no lights on. Hit the brake lights and watch the amp meter go into discharge. Turn on the headlights and it will go way down on the amp meter. Rotate the 3rd brush down closer to the output brush so that the amp meter won't dip below the centerline with the lights on or at least not too much below the centerline. A person wants the battery to charge a little bit anyway. Add turn signals and brake lights and all that intermittent stuff and the amp meter will drop with the load. This is why so many folks are going to LEDs for all of the lights. With halogen headlights, a person has to have an alternator just to keep up with the load. With LEDs the old three brush will have longer legs toward keeping up with the load. If a person runs at night a lot then they have to adjust for that load and then run the lights in the daytime too if they don't want to keep adjusting the brush. This will keep the battery from being overcharged at that amp setting.
 
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rotorwrench,
I appreciate you taking the time to provide your feedback. I should mention that I was having trouble getting the conventional flasher to work. I was told that I needed to use this type of flasher since the positive ground issue made the signal lamps on my '40 Ford "hyperflash" using the standard flasher. This kind of flasher corrected the problem completely, so I thought it would operate the same on the Model A but such is not the case. I suppose it has something to do with the 3 brush generator and the way it functions.

*I just got an email from LEDlight.com that I need to install "load equalizers" on all 4 bulbs. I'll get a set of them and let you know if that fixes the problem.
:)
 
You need to ground the case. You can test this by running a temporary ground wire. Just make sure it is a good ground.

You can ground to the painted steering column by using a star washer. That type of washer will cut through the paint.

You should not have to replace the flasher. The instructions say it will work up to 20 amps.
 
The model A ignition HT wire radiates a lot of RF interference. We had a backing camera on a 12 volt Town Car that would light up with the engine off and and go blank with it running. With the car turned off the camera was going and when another model A right next to the non-running one was started, the camera in the non-running one went blank. So I replaced the copper core coil HT lead in the car with the camera that would not run with a resistor (carbon core) one and the camera immediately worked properly with its engine running.
With that experience in hand, I later had the same problem with a 1952 2.5 litre Riley, but this time it was the LED indicators that did the same thing with an electronic flasher unit. First I tried a separate battery for the flashers, then the car battery circuit for the flashers and the separate battery to run the car ignition. Still the indicators flashed with the engine not running and did not when it ran. Shielding the plastic electronic flasher can in a tin can connected to earth did not solve the problem, nor did wrapping it in earthen aluminium foil.
So, rather unwillingly, I put in a carbon core HT lead and immediately the flashers worked with the engine running. The spark was not as strong on my spark gap tester, but still in the OK zone and the Riley still started well. There were about 5500 ohms resistance in the wire and I kept cutting it shorter until at about 3300 ohms the indicators stopped working again with the engine running. So I put in a longer piece of carbon HT wire having about 3700 ohms, everything worked and I left it at that.
So maybe try a piece of carbon core resistor wire for the HT lead and if that makes things work you will have diagnosed that it is RF interference that is upsetting the flashers. What you do from there is your decision. I personally like copper cored HT leads in 6 volt Model As, so have no backing cameras in mine.
My Model A flashers are incandescent bulbs in the front and LED in the rear with bimetallic flasher cans in both cars. I added load resistors at the front in my roadster and hidden extra bulbs behind the dash in my wife's 6 volt Tudor to draw enough current in both to heat up and make the bimetaliic strips work.
RF from the HT leads may not be your problem, but putting in a bit of old carbon core thrown out from modern car is an easy experiment, as long as you check it for continuity with an ohm meter first to make sure it was not discarded because it broke Internally!
SAJ in NZ
 
Many thanks to all for the thoughtful responses. As soon as the load equalizers are installed, I'll report on what difference they made, if any.
 
It sure looks like you're using a standard lighting system, nothing fancy.

The flasher in the pic doesn't look thermal. It looks electronic to me, maybe I'm not seeing something though.

The flashers should work with a GOOD 535 thermal flasher. Nothing else should be needed. Most of the new chinezium flashers are pretty much junk.
 
Load equalizers are for LED bulbs. Incandescents won't need them. Run LEDs if you use 6 Ohm resistors.

SAJ has a point about radio frequency saturation around solid state type electrical equipment. The solid state flasher unit may well be having a problem with RF saturation. It certainly won't hurt anything to try a carbon core lead for the coil's high tension output. The solid wire core has a tendency to bleed an RF buzz whenever the engine is running. This was the reason manufacturer's went to carbon core high tension leads. The car will still have the copper or brass strips from the distributor to the spark plugs but the RF saturation would likely be cut in half at least. Those would be impossible to shield unless a person changed to a distributor that used regular leads to the spark plugs. It would be worth a try on the coil wire.

A standard bi-metallic flasher has to have either all four incandescent bulb of the 1154 type to function well or at least a higher candle power bulb such as was used for the brake lights in early cars. That bi-metallic switch needs a good load to function properly. If the load is too high they will slow flash. If the load is too low such as one bulb is burned out then they will hyperflash due to the low load not pulling the switch open far enough'. The bi-metallic has to get good and hot to function well.

Polarity should have no effect unless the solid state flasher was made for positive ground and a person tries to use it on negative ground. A lot of solid state stuff is polarity sensitive. The old tube type radios had an electromechanical ******** to make the step up coils work. They were not polarity sensitive but a lot of folks have there radio repaired and the tech puts a solid state PDC device in to replace the old ********. They have to use a positive ground type unit if the car is still positive ground or the raio won't work.
 
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