Any electronic experts out there
 

I am 12 volt neg. ground, have installed led front running lights/sequential turn signals. Running lights are white and powered on via a switch and turn amber when the turn signal is turned on and flash a sequential signal. With the car not running all lights work as they should, when the car is running the lights work fine for a very short time and then will go on and off switch to turn signal and do what ever they want. Simple hookup, fused power and ground. All connections are good, as I said all is fine until I start the engine. I am guessing some sort of interference and I need a "filter" (lack of better term) to stop the interference. Any idea of what "filter" I could use to block this?
PLEASE no scarcasm. We all do things to our cars for safety, uniqueness, points or just plain fun, I am asking for help Thanks

Re: Any electronic experts out there
 

I had the same problem with my turn signals. Put these on my plug wires, and it solved the problem. It’s only a stop gap until I can put together a larger suppression core ignition wire set.

Cedmon 20 Pieces Clip-on Ferrite... https://www.amazon.com/dp/B07CWCSNW9...p_mob_ap_share

If you’re using the exposed wire ignition then I’m not sure.

Any electronic experts out there
 

By any chance, are you using an electronic flasher?

I had a similar problem with my electronic flasher and LED tail lights. The flasher worked perfectly with the engine off and went nuts with the engine on. I wrapped the flasher with several layers of tin foil, and that helped a bit. But, it didn’t fix the flasher. I returned the flasher to the vendor.

I went back to a new thermal flasher from Bratton’s. It blinked irregularly, but it at least worked (for a few weeks). Then, it died.

Some folks recommend a NOS 535 thermal flasher, which I currently have installed (from eBay). It kinda works. The blink is still sometimes irregular, and the indicator lamp seldom works on my Signal Stat turn signal switch. I use my cowl lights as turn signals. Adding an electrical “load” with 10 CP bulbs (instead of stock 3 CP bulbs) in the cowl lights helped stabilize the 535 flasher, but the flasher still does not work quite right. However, the blink is safe enough to drive.


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Re: Any electronic experts out there
 

Johnny Nitro thanks for the info, I am running the old style dist. cap and strip plug connectors and modern points. I will switch to a modern cap and wires and give the noise suppressors a try.
Johnny what do you mean by a larger suppression core ignition wire set?

Re: Any electronic experts out there
 

Shew01, I am using a thermo flasher with LED rear lights (turn,tail and brake) and also a third brake light with signals, rear lights have load resistors. Front turn signals are also LED running/driving lights. The in line resistors, Snyders A-13464 solved the flashing problem for me. Have also considered turning my parking lights to turn signals. (Two-lite headlights)
Being in the country and driving dark roads on the return ride from tours I want to be very visible.

Re: Any electronic experts out there
 

Thanks to Johnny Nitro and Shew01 for the information supplied.
Any other ideas from you Barners please jump in. THANKS

Re: Any electronic experts out there
 

535 is a 6V flasher. 550 for 12V. Thermal flashers require 1-2A draw to operate, so add
an extra incandescent to the circuit. If above doesn't work try a 5A diode between coil and lamp supply. Could be back EMF from the coil.

Re: Any electronic experts out there
 

Thanks Badpuppy, I am using the 550 with load resistors and have a nice steady flash.
The "noise" from the ignition is what I believe is messing with my front turn signals/driving lights. Going to switch to a modern cap and wires with the "noise suppessors" that Johnny Nitro suggested.

Re: Any electronic experts out there
 

Every time a switch (in this case, a set of points) opens and closes, RF noise is generated. Add that to the original, uninsulated, unshielded copper spark plug wires and you have an antenna emitting high energy noise into the engine compartment. If you want to run modern electronics, you MUST remove the noise. Shielded spark plug wires and a modern style cap are a must. I know it's not for the purist, but most of your problems will go away...


Frank

Re: Any electronic experts out there
 

X2.


Was reading the reviews, some complained they did not help with LED shop style lighting. These will only help with noise generated/emanating from the wiring they are attached to. In LED lighting where the noise is in the fixture and not in the power cord and wiring directly attached to the power cord, they will not work. Basically the ferrite material in the cores (they are not a magnet) absorbs the high frequency energy that cause the interference.

Re: Any electronic experts out there
 

Frank, Sounds like you have experience in automotive electical noise theory/design.
I am not familiar with automotive, but have experience with electrical and electronic noise testing/shielding/emissions/circuit design in electronics.



Since a car's noise in the A is a circuit completed by spark at the rotor and spark plug, does putting a ferrite core on the coil wire efficiently reduce electrical noise on the coil wire and plug leads?



Thanks

Re: Any electronic experts out there
 

Very interesting light set up, would like to see pictures of them working engine off. I'am wonder if a separate power source not being charged by the A if that would work ? At least try ?

Re: Any electronic experts out there
 

Yup, I put LEDs in my parking light sockets and they work fine with the engine off but at an idle they look like a strobe light. Interestingly enough, raising the revs to a fast idle or higher makes that stop. In my case I'm wondering if the ignition is drawing enough power to drop the voltage below the dropout voltage of the LEDs every time the points close. Then the gen kicks in and gives them enough juice?


Anyway.. sorry for the tangent. I wouldn't think there would be any issue with interference with a thermal flasher. Do your rear signal lights behave just as erratically or is it just the fronts?

Re: Any electronic experts out there
 

LEDs work with very little problems until they are used in a situation where a light has to blink on and off.

The old sequential turn signals used in the Thunderbirds and Mercury Cougars back in the 60s were operated by an electric motor that turned the lights on and off with a cam action switch and they were relatively reliable. When they try to use modern electronics, things can be problematic. Where some of these designs come from may have something to do with it. LEDs used in turn signal applications have problems with flasher units for reasons already mentioned. The electronic breakers for those are also questionable about origin and quality.

While ignition noise may have an effect, it may not be your problem. To replace an entire ignition system only to realize it doesn't fix the problem could be expensive in more ways than one. When a car is off, the battery carries the load. When a car is operational, the generator or alternator carries the load and there are more loads in operation so it's harder to tell where the problem is coming from. RF noise from ignition systems usually only affects radios since they are basic receivers and they pick up the noise through the antenna. The LED systems can also have an affect on radio reception but I don't know about the other way around.

A lot of it may have more to do with how the generator or alternator carries the load. Does the car still have a generator or is it now an alternator? Alternators are designed to completely change the AC current they generate to DC current but they don't always do as good a job as we would like. Sometimes a bit of the AC gets through depending on the condition of the diode bridge inside.

Re: Any electronic experts out there
 

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Re: Any electronic experts out there
 

Ryan, Have you tried running dedicated grounds? Have heard that sometimes that strobing is caused in led lights because they require a good solid ground due to their low current draw.

Re: Any electronic experts out there
 

There is another option if your issue is due to radiated noise, and is not conducted noise through the wiring into the flasher unit.




You can try to shield the sensitive components. We do not know where your electronics is, but fab a shield using a few layers of aluminum foil that wraps entirely around the electronics. 1st try shield un-grounded, then try grounding the foil. This is something easy/quick to try to troubleshoot.



Just for kicks you additionally at the same time could try doing the same with the distributor body to attempt to reduce amount of radiated noise due to the rotor arcing. You would have to insulate the shield so the high tension and plug wires/etc do not short out the plugs.


I've often wondered the effect of resistive wires or resistor spark plug wire caps have on the quality of the spark plug spark. Old motor cycles use 5k ohm caps, Without the 5k ohm caps the plug spark seems more intense. So I wonder if these types of wires/caps affect the Model A performance, perhaps the plugs do not run as clean/etc?


If you really run into issues, perhaps try talking to an car stereo installer with experience on classic cars.

Re: Any electronic experts out there
 

Yup, I added dedicated grounds when I was testing out the LogoLites. Those didn't have any strobing issues. These bulbs were just cheapies from amazon, they work on 6-12V. I think the dropout voltage is right at 6V so there isn't much wiggle room if the generator isn't charging.

Re: Any electronic experts out there
 

I have some experience... Worked for 30 yeas as an electronics engineer. Not sure if a core placed on the coil wire would work, since the high energy bursts are also picked up by the bare copper strips. They will most likely receive RF as well as transmit it. Modern wires are carbon core rather than copper for that reason. You could try it and see if it works, but the RF is generated in the distributor where the wires are.



On grounding, When I put LED tail lights on my roadster, they failed within two months. I sent them to United Pacific and they replaced them. They said they had most likely failed due to a high power surge. Looking at the mounting for the generator, I suspected that the ground was poor, since it is only grounded through a single bolt. I then placed a heavy ground strap from the generator case to the nearest engine bolt and they have not failed in 5 years. I know this doesn't prove the surge theory, but it's enough for me...


Frank

Re: Any electronic experts out there
 

Right now, I have a copper core ignition wire set. I believe it’s 7mm. Modern ignition wires (although we’re at the point of coil on plug, so maybe not so modern anymore!) are designed to reduce interference from the ignition using shielded or suppression core. Not sure of the exact science behind it. I plan on making my own custom set of plug wires using 8mm suppression core! And seeing if that helps.

Oh, yeah, one more thing: I am using all led turn signals, a 7 wire vintage Yankee turnflex, and a dedicated made in USA led flasher module (CEC?)

Ferrite cores on my four plugs eliminated my erratic flash. The other option that worked was disconnecting the “P” wire from my three prong flasher, but then you lose the benefit of your turn signal unit indicators.