Ok here's the deal. Turn signals and hazard lights all work. I just replaced the pea lights in the tach. I have no voltage to the socket, When I checked the wire it goes to ground. Looking for someone with more undamaged brain cells for trouble shooting ideas.
Brian

Next problem. Just replaced the high beam pea light. Again no joy. Low and high beams work fine. I have weak voltage to the socket.
Thanks

Ok
I got it. Thanks to Timothy nd28 ( the led instrument guy) who helped me through trouble shooting my electrical issues. This car thinks it going to beat me but thanks to the great people in the 914 world I'm off to the next battle.

Did you have them in backwards? LEDs won't shine if "back biased".

--DD

I would like to piggy back on this thread.....'73 2.0 with normal light bulbs and when you use turn signals first flash or two bright and clear in chosen indicator, then both indicators will blink at the same time but at only half brightness. Has been like this for years and I have scrubbed every ground in the car. Any ideas welcome.....thank you!!
gg

Your problem sounds like a issue with the flasher unit. The flasher unit has 2 sets of switches within, one set for the dash indicator lamps while the other set is for the exterior turn signal lamps.
I had a similar issue a few years ago and thought it was from a failing electrolytic capacitor inside the flasher. So, I replaced it with a ceramic style and things got worse
I think if you replaced the flasher, your problem would go away.
Alternatively, I never liked or understood why the indicator light needed to be isolated and needed its own set of switches. You could do what I did and abort the flasher unit, and wire the directional indicator lamps straight to the wires of the hazard light switch. You would get full voltage and the added load from the gauges' two tiny lightbulbs is negligible.

I've had the same problem since I bought the car 7 years ago. I replaced the flasher with another one (used ) and it didn't solved the problem. I always though that I needed to go in and clean the grounds but you have done that without success...

I like Timothy's idea of connecting to the main circuits . Strange that they have them separated

The tach turnsignal indicator lights flashing correctly then both flashing at 1/2 brightness is a failure of the secondary coil in the flasher.

See drawing below and notice the coil in the flasher relay in series with pin 49a. As turnsignal bulbs light up, the bulb current energizes this coil and closes the contact for pin K which powers the center tap of the 2 tach indicator bulbs.

As the flasher ages (40 years!) and the efficiency of the coil decreases, the contact does not close and both tach bulbs shine at 1/2 brightness.

You can replace the flasher relay with another OEM flasher and hope new flasher works, or keep the original flasher and rewire the tach indicators with a jumper pigtail shown below.

Click to view attachment

Click to view attachment

Click to view attachment

That jumper is a very elegant and easy way to bypass the flasher circuit, love it!

Wow!! What a great response.....thank you very much! I look at that jumper and cannot figure out how it only lights up one side at a time? Please send another picture with maybe a bit more explanation for us slow learner? Also, could someone please send a picture of the flasher unit in place on the car? This seems like the easy way out. Thank you again you guys...
gg

Here's a simplified diagram of how the flasher circuit looks when the flasher is on for a right turnsignal.

The flasher output 49a connects the right side bulbs to the battery and thus they light up.

Flasher output K also turns on and connects the center connection of the tach indicator bulbs to the battery.

Notice the right side indicator is connected to the left outside bulbs and the right side indicator is connected to the right outside bulbs.

When working correctly, the right side indicator current goes from the battery, through output K, through the indicator, and further through the left side exterior bulbs. Since standard bulbs need a lot of current to light up (>1A), the small current of the right side indicator does not light up the left exterior lights.

The diagram below shows what happens when the flasher K lead fails. Again the right side turnsignal is on (49a contact to the battery is closed) but the secondary coil controlling the contacts for output K has failed and remains open.

Now the center tap of the 2 tach indicator bulbs is not driven by output K. In this case output 49a powers both indicators (now in series) and then through the left side exterior bulbs.

Man I love the wealth of knowledge and helpfulness of this place. Lends credence to the expression "None of us is as smart as All of us."

I use "us" informally, as I don't personally contribute to the knowledge.

But go Us!

Thank you to the contributors to this post and OP. I finally have a working turn signal indicator light on the tachometer on my '74 2.0. After reading this post, I ordered a new turn signal/flasher relay and finally had time to install it today. Upon removing the old one, I noticed it only had three prongs (VW/Audi part #111 953 227 D) which gave me alarm because the new one (Werhle Relay #914-618-303-11/206) had four contacts for spades. A nervous glance to the socket and it had four female contacts. Pressed it in and voila! Maybe the previous owner had not been reading 914 World.