The Ford Barn

Bill Goddard · 08-08-2014, 04:40 PM

When the engine is off, the flashers work great - they are everything you would want. But with the engine running the turn signals stay on with a slight flicker.

I am using a 12v neg grnd alternator putting out 14.57 v,
LED tailights and LED front fender lights.
The flasher is an electronic heavy duty no. 90651 (Taiwan) marked for use with LED lights

Why does all this stuff work so well with the engine off and so badly when it is running?
Bill G

P.S. · 08-08-2014, 05:21 PM

The electronic flashers are very sensitive to RF energy on the wiring. Your Model A ignition system creates a LOT of spikes of RF energy with the motor running. Some snap-on ferrite chokes might help.

Bill Goddard · 08-08-2014, 06:12 PM

What is a snap on ferrite choke and where can I get one. Bill G

P.S. · 08-08-2014, 06:35 PM

Here is one -http://www.dxengineering.com/search/part-type/rf-suppression-snap-on-ferrite-beads

Del in NE Ohio · 08-08-2014, 07:34 PM

I fought the same fight... Tried RF shielding, RF Chokes..... couldn't tame it. Finally had to insert a resistor on each (RT and LT turn signal circuit.

Willie Krash · 08-08-2014, 07:36 PM

Sponsored Links (Register now to hide all advertisements)

Years ago when I worked for cable TV, when we had RF problems we would wrap the amp in tinfoil. Now this was just for trouble shooting but I'm lazy. If shielding the flasher works you can determine which course to take.

08-08-2014, 04:40 PM	#1
Bill Goddard Senior Member Join Date: May 2010 Location: Shrewsbury,Pa Posts: 516	Turn signals don't work w/ engine running When the engine is off, the flashers work great - they are everything you would want. But with the engine running the turn signals stay on with a slight flicker. I am using a 12v neg grnd alternator putting out 14.57 v, LED tailights and LED front fender lights. The flasher is an electronic heavy duty no. 90651 (Taiwan) marked for use with LED lights Why does all this stuff work so well with the engine off and so badly when it is running? Bill G

08-08-2014, 05:21 PM	#2
P.S. Senior Member Join Date: Jul 2012 Location: Hazzard County Posts: 1,922	Re: Turn signals don't work w/ engine running The electronic flashers are very sensitive to RF energy on the wiring. Your Model A ignition system creates a LOT of spikes of RF energy with the motor running. Some snap-on ferrite chokes might help.

08-08-2014, 06:12 PM	#3
Bill Goddard Senior Member Join Date: May 2010 Location: Shrewsbury,Pa Posts: 516	Re: Turn signals don't work w/ engine running What is a snap on ferrite choke and where can I get one. Bill G

08-08-2014, 06:35 PM	#4
P.S. Senior Member Join Date: Jul 2012 Location: Hazzard County Posts: 1,922	Re: Turn signals don't work w/ engine running Here is one -http://www.dxengineering.com/search/part-type/rf-suppression-snap-on-ferrite-beads

08-08-2014, 07:34 PM	#5
Del in NE Ohio Senior Member Join Date: May 2010 Location: Columbiana,OH Posts: 467	Re: Turn signals don't work w/ engine running I fought the same fight... Tried RF shielding, RF Chokes..... couldn't tame it. Finally had to insert a resistor on each (RT and LT turn signal circuit.

08-08-2014, 07:36 PM	#6
Willie Krash Senior Member Join Date: Jan 2012 Location: Phoenix, Oregon Posts: 661	Re: Turn signals don't work w/ engine running Sponsored Links (Register now to hide all advertisements) Years ago when I worked for cable TV, when we had RF problems we would wrap the amp in tinfoil. Now this was just for trouble shooting but I'm lazy. If shielding the flasher works you can determine which course to take. __________________ Mike Stitt "A business that make nothing but money is a poor business." -Henry Ford