I ran into this issue after a couple of modifications to my MGA. I had rebuilt the 1500 type turn signal relay box using a pair of miniature sealed relays, after which I could no longer hear the relays click. I also installed the 4-way flasher circuit using a heavy duty flasher unit, but the flasher unit is not physically mounted on the firewall, so I can't hear the flasher unit clicking either. If you use an electronic flasher unit, those may not make any noise at all. My problem was not so much with the turn signals, as those are self-canceling on the MGA by pneumatic time delay. But I do occasionally use the 4-way flashers, and it is all too easy to forget to switch them off.

This gadget is even simpler than the headlights-on warning buzzer, no relay required. All you need is one of the cheap buzzers and a couple of wires. Splice one side into the turn signal warning light wire, and ground the other side. Mount the buzzer anywhere you like, even epoxy it to back of the dash panel.

      Pick any 12-volt DC noise maker of your choice.
Piezoelectric buzzer from Radio Shack works fine.
www.radioshack.com/product/index.jsp?productId=2062397
www.radioshack.com/product/index.jsp?productId=2062402
www.radioshack.com/product/index.jsp?productId=2062403


If you have a different car with two turn signal indicator lamps, You could install two buzzers, one for each lamp. Easier yet, you can connect a pair of very cheap diodes from the two lamps to one buzzer, or connect the buzzer to the output of the flasher unit.

On 1/2/2021, Tony Hanks wrote:
"I fitted a buzzer as per the suggestion on your page .. ET-245A. That indicator light is so hard to see on a sunny day! I used a 12V Piezo Buzzer, but the sound was too loud. When stopped at lights you could see pedestrians distracted by the noise from my car.

So I have now changed it to an electrical mechanical buzzer that effectively makes a clicking sound. The item at my electronics store was: BUZZER ELECMEC 5-15VDC MINI ($2.95) - As with the Piezo, I bolted this to one of the horizontal braces for the dashboard, using an existing hole".

Yes, this one clicks like a turn signal flasher unit, not buzzing or beeping. Will try to get the part number.