I've been going through electrical on my73 resto and have one last gremlin to chase. All of my lights work as expected including e-brake indicator flasher and hazards. One last thing that isn't working are the turn signal indicators in the tach. I'm thinking the flasher (still the original Hella unit) may just be getting tired but thought I get expert opinions.

The left indicator sometimes works as expected but often flashes correctly for a minute or so and then starts flashing both sides. The right indicator almost always flashes both sides. Rarely it will flash correctly. Neither indicator flashes when the hazard switch is pulled. Can't remember if they are supposed to flash when hazards are on.

There are NO LEDs in the flasher system. I figured I'd take that out of the equation for troubleshooting. I should add that this is just running off the fully charged battery at 12v. No engine installed. This is a fully refurbished harness and I've triple checked all my switch and bulb connections. After scratching my head all day, I'm thinking the flasher may be just at it's limit of being able to respond to the load. I can't say I fully understand how this funky circuit operates though. I plan to switch to all LED signal and indicator bulbs and have read the thread by @Spoke on LED compatible flashers. I just thought I'd check if there is anything I've overlooked.

I did pop my flasher open and it is clean as a whistle inside. I wonder if replacing the two capacitors would rejuvenate it.

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If the turn signals are flashing properly, it is not the flasher. Most likely a wiring or connector problem. Could be a bad ground that always makes things interesting.

I had a similar problem on a VW recently and it turned out to be caused by 6V bulbs in the indicators. Everything worked properly, then I had the speedo rebuilt and the shop installed all new bulbs at the same time. Turns out a couple of them were 6V.

Mine always behaved similarly. It would work as expected but after maybe 15-30 seconds both would flash at about half brightness (did this regardless of R or L position). I recall mentioning this somewhere on this forum when I began my restoration and a few others chimed in that they had they same issue but didn’t know how to fix it. Hopefully you get to the bottom of it. Per your question, on mine both would flash when the hazards were on.

@bbrock

The turnsignal indicators not working in the tach are caused by the 2nd coil in the flasher losing its efficiency over time. Sometimes you'll get one flash or 2 then both indicators will flash together. I'm not sure there's any way to refresh the coil. The coil that does the tach indicators is the one with the heavy wire.

The LED-compatible EP26 flasher can work properly in place of the OEM flasher and if you switch to LEDs anytime in the future the EP26 will flash normally.

The only issue with the off the shelf EP26 is that the C2 pin which powers the tach indicators is open circuit on the stock EP26. This is why I resell EP26. I pop open the flasher and add one little wire. I show where to add the wire on my website if you want to do it yourself.

Thanks guys. I did another search on "Turn Signal Indicator" instead of just flasher and got a LOT more hits. Common problem/question and same answer. Yes, it appears to be the flasher wearing out as explained by Spoke here:

http://www.914world.com/bbs2/index.php?s=&...t&p=2571927

and the solution is to either buy a modified EP26 relay from Spoke, or modify one yourself as he explains here:

https://www.spokeworksled.com/ep26-mod-single-indicator

or rewire the indicators to eliminate the "C" circuit.

I found that solution in my search yesterday but always in context of making the flasher LED compatible. This seems to confirm that the secondary coil in the flasher responsible for driving the indicators does wear out over time and stops pulling in as it should. I'm wondering though if the modified relay still senses the load and causes both indicators to flash if a bulb is burned out or connection is lost. That is the purpose of the original system and a nice feature to have.

Thanks only question left is the last one in the message I was typing when you posted your reply. Does the modified flasher still sense load to indicate when you have a burnt bulb or broken wire by flashing both indicators like the original.

Another question just out of curiosity - what causes the secondary coil to lose efficiency? Is it the relay itself or perhaps one of the two capacitors on the board aging? I didn't trace the circuit on the board when I had it open to see how the current flows.

Thanks for all that you do for us!

The issue with OEM flashers and LEDs is that OEM flashers from way back were designed to hyperflash (2x normal flash rate) when a bulb burned out to alert the driver to the issue. The 911 flasher does this. The 914 flasher does not do this because the 914 designers wanted to also use the flasher to flash the brake warning lights so they needed to design the 914 flasher to flash at very low bulb currents.

Thus with the OEM 914 flasher, a burned out bulb is sensed by the tach indicators doing funny things like both L and R indicators flashing together or with later cars the single L<>R indicator not flashing at all. The EP26 will not sense a burned out bulb.

I don't think replacing the capacitors will help but you can try replacing them if you want to.

I'm happy to report that I popped a modified EP26 in this morning and all lights, signals, and indicators on the tach are working properly. @Spoke is a genius.

Truth - but you ain't bad yerself.