Strange LED lights behavior

[Showdown]

I am upgrading all of the lights on my car to LEDs. I have changed out everything and so far so good... except with respect to the front turn signals. I installed the LEDs and the hazards work as they should; all four lights come on at a slow flash rate, but when I engage the turn signal (either to the left or right) both front turn signals and both rear turn signals come on, the tach gauge signal light doesn't and they flash at a the same rate as the hazards; slow.

Strange thing is that when I put the incandescents back in the front turn signals everything works as it should.

I have a new working relay and the strange behavior only happens with the front turn signal LEDs.

At first I thought it was the LEDs I bought so I bought some from Carmagic and the same behavior persists.

Anyone ever seen anything like this?

[acme911]

If you haven’t, you might have to install resistors inline. The problem you describe is pretty common. Not just with 911’s, But with other makes as well when converting over to LED.

[RSBob]

+1

[dfhtrhjn]

I had a similar issue, resistance is the culprit if I remember correctly. Some bulbs are made to account for that so I shopped around and found some that work fine.

[djpateman]

Essentially the LED`s draw so little current that the flasher relay cannot function properly. When the four-way is on, then there is just enough draw to make it sort of work.
An don`t even think about using an LED for the alternator light, that is just asking for big problems.

[spoke]

Originally Posted by Showdown

I am upgrading all of the lights on my car to LEDs. I have changed out everything and so far so good... except with respect to the front turn signals. I installed the LEDs and the hazards work as they should; all four lights come on at a slow flash rate, but when I engage the turn signal (either to the left or right) both front turn signals and both rear turn signals come on, the tach gauge signal light doesn't and they flash at a the same rate as the hazards; slow.

Strange thing is that when I put the incandescents back in the front turn signals everything works as it should.

I have a new working relay and the strange behavior only happens with the front turn signal LEDs.

At first I thought it was the LEDs I bought so I bought some from Carmagic and the same behavior persists.

Anyone ever seen anything like this?

I assume you have LEDs in the rear turnsignals as well? What you are seeing is expected when changing to LED turnsignals with the older 911's.

The older 911's have a similar layout to the 914 '70-'73 turnsignals as shown below. To alert the driver of a burned out turnsignal bulb, the OEM flasher has a 2nd coil that energizes when the turnsignal is active. This powers the K pin of the flasher to 12V. The K pin powers a common connection between the turnsignal indicators in the tach. When a turnsignal bulb burns out, both L and R turnsignal indicators will flash together alerting the driver of a burned bulb.

Notice how the tach indicator bulbs are connected from the L to R sides of the turnsignals. This is what is causing both sides to flash.

When you change to LED turnsignals, the low current of the LEDs does not energize the 2nd coil and the K pin remains open. Thus powering the L or R turnsignals causes the tach indicators to power the opposite side turnsignals.

The EP26 flasher relay is LED-compatible and pin-compatible with the 911 OEM flasher. The only issue with the off-the-shelf EP26 is that the K (or C2) pin on the EP26 is not connected internally. I resell EP26 with the C2 pin grounded for the 911. You can purchase the EP26 from most online retailers and make the mod yourself if you want. On my website I show where to connect a wire inside the EP26 to ground C2.

BTW, when you use EP26 with C2 grounded, you'll find the L and R turnsignal indicators in the dash will flash opposite. This is easily remedied by pulling the indicators like you're going to change the bulb and just put them in the opposite position. Do not pull wires from the indicator fixture.

[7783911]

i switched to Spokes relay and have had no issues since

[brighton911]

Hats off to Spoke for such a well written explanation and offering the necessary parts to do the job right.

[Showdown]

Originally Posted by brighton911

Hats off to Spoke for such a well written explanation and offering the necessary parts to do the job right.

Between Spoke and Engelbert I now have ridiculously clear instructions as to how to fix the issue and explanations of why it manifested itself.

Thanks gentlemen!!

[Codyatx]

Originally Posted by spoke

I assume you have LEDs in the rear turnsignals as well? What you are seeing is expected when changing to LED turnsignals with the older 911's.

The older 911's have a similar layout to the 914 '70-'73 turnsignals as shown below. To alert the driver of a burned out turnsignal bulb, the OEM flasher has a 2nd coil that energizes when the turnsignal is active. This powers the K pin of the flasher to 12V. The K pin powers a common connection between the turnsignal indicators in the tach. When a turnsignal bulb burns out, both L and R turnsignal indicators will flash together alerting the driver of a burned bulb.

Notice how the tach indicator bulbs are connected from the L to R sides of the turnsignals. This is what is causing both sides to flash.

When you change to LED turnsignals, the low current of the LEDs does not energize the 2nd coil and the K pin remains open. Thus powering the L or R turnsignals causes the tach indicators to power the opposite side turnsignals.

The EP26 flasher relay is LED-compatible and pin-compatible with the 911 OEM flasher. The only issue with the off-the-shelf EP26 is that the K (or C2) pin on the EP26 is not connected internally. I resell EP26 with the C2 pin grounded for the 911. You can purchase the EP26 from most online retailers and make the mod yourself if you want. On my website I show where to connect a wire inside the EP26 to ground C2.

BTW, when you use EP26 with C2 grounded, you'll find the L and R turnsignal indicators in the dash will flash opposite. This is easily remedied by pulling the indicators like you're going to change the bulb and just put them in the opposite position. Do not pull wires from the indicator fixture.

Can you share a link to purchase the relay? I’m having the same issue.

[Mr. Merk]

Originally Posted by Showdown

Strange thing is that when I put the incandescents back in the front turn signals everything works as it should.

There, you fixed it.

[spoke]

Originally Posted by Codyatx

Can you share a link to purchase the relay? I’m having the same issue.

https://www.spokeworksled.com/product-page/ep26-led-compatible-flasher-for-911-71-73-914