Making Your Flasher Relay LED Compatible Options

[Spoke]

This thread is meant to help those implementing LED turnsignals on their 914.

Standard flasher relays were designed to flash 2 standard bulbs (21W each) for turnsignals or 4 standard bulbs with 4-ways on.

LED replacements burn between 2W and 5W and electrically may not behave at all like a standard bulb. The LED replacements can cause all kinds of weird things like hyperflash (2x normal flash rate), dash indicators do not work, or the the flasher relay does nothing at all.

The 914 flasher is different for early cars 70-73 than later 74+ mainly because of the tach indicators. Early cars have individual L and R indicators and the 74+ have a single L+R indicator. Both are handled differently by the flasher.

There are LED-compatible flashers generally available at your FLAPS which are plug-in but not totally function compatible with the 914 standard flasher. The functional issue revolves around the 4th terminal which the 914 uses to activate the dash indicators.

The aftermarket flasher relays are EP26 (4 terminal) and EP36 (3 terminal). I've seen these at Pep Boys, Autozone, and Advance Auto to name a few FLAPS, usually for less than $15.

I'll detail the differences between early and late cars, as well as EP26 and EP36 in the next few posts.

[Spoke]

When LED turnsignals are installed, funny things happen when the OEM flasher remains in the vehicle. Installing a modified EP26 LED-compatible flasher alleviates these issues but requires the left and right turnsignal indicators in the tach to be swapped.

The left side diagram shows the case with an OEM flasher and LED turnsignals.

For the OEM flasher, like the case with standard turnsignal bulbs and the K relay coil weakened and non-functional, with high impedance LED turnsignals, the K relay coil does not activate when flashing and stays open.

Now the left and right turnsignal indicators are driven by the 49a lead through the left side LED turnsignals. But where the standard bulbs are very low impedance, high power bulbs, the LED turnsignals present a high impedance and thus a much lower power load.

This causes the LED turnsignals to share the voltage with the turnsignal indicators and the indicators light gently and so do the LED turnsignals light gently. Several owners have seen this happen when changing to LED turnsignals. This ghosting of the opposite side turnsignals may not happen if only the front or rear turnsignal is LED and the other a standard bulb.

When the OEM flasher is replaced by a modified EP26 flasher (K/C2 connected internally to ground) as shown in the right diagram, most turnsignal indicator issues are solved.

Now the center connection of the indicators is connected to ground through the K/C2 pin. When the RIGHT turnsignal is flashing, the LEFT turnsignal indicator flashes. This opposite connection has been debated in other threads even if it exists at all although experience has shown this to be the case. After changing to LED turnsignals and EP26 flasher, many 914 owners have noticed the wrong indicator flashing after the conversion.

The simple fix for this wrong indicator flashing issue is to pull the tach out, then pull the indicator bulbs and their sockets and swap the entire fixtures. The wires could be pulled off of each indicator and swapped but this may lead to broken wires. It's much easier to pull the entire socket and bulb and just swap them.

[ClayPerrine]

When LED turnsignals are installed, funny things happen when the OEM flasher remains in the vehicle. Installing a modified EP26 LED-compatible flasher alleviates these issues but requires the left and right turnsignal indicators in the tach to be swapped.

The left side diagram shows the case with an OEM flasher and LED turnsignals.

For the OEM flasher, like the case with standard turnsignal bulbs and the K relay coil weakened and non-functional, with high impedance LED turnsignals, the K relay coil does not activate when flashing and stays open.

Now the left and right turnsignal indicators are driven by the 49a lead through the left side LED turnsignals. But where the standard bulbs are very low impedance, high power bulbs, the LED turnsignals present a high impedance and thus a much lower power load.

This causes the LED turnsignals to share the voltage with the turnsignal indicators and the indicators light gently and so do the LED turnsignals light gently. Several owners have seen this happen when changing to LED turnsignals. This ghosting of the opposite side turnsignals may not happen if only the front or rear turnsignal is LED and the other a standard bulb.

When the OEM flasher is replaced by a modified EP26 flasher (K/C2 connected internally to ground) as shown in the right diagram, most turnsignal indicator issues are solved.

Now the center connection of the indicators is connected to ground through the K/C2 pin. When the RIGHT turnsignal is flashing, the LEFT turnsignal indicator flashes. This opposite connection has been debated in other threads even if it exists at all although experience has shown this to be the case. After changing to LED turnsignals and EP26 flasher, many 914 owners have noticed the wrong indicator flashing after the conversion.

The simple fix for this wrong indicator flashing issue is to pull the tach out, then pull the indicator bulbs and their sockets and swap the entire fixtures. The wires could be pulled off of each indicator and swapped but this may lead to broken wires. It's much easier to pull the entire socket and bulb and just swap them.

I put a set of LED bulbs into Elwood, and used an EP26 flasher. That made the turn signal bulbs act weird. So I removed the two connection bulb sockets from the back of the tach, and replaced them with single connection bulbs that ground through the tach. The wires that go back to the flasher are just disconnected. Now the turn indicators work fine.

From your diagram, your modified flasher does basically the same thing.