The 'E' Type Forum

Having purchased a new indicator switch to replace my original (unfixable) I fitted it.

Only to find that the switch arm rotated in the housing, meaning that I couldn't actuate the switch.

After trying to wick some superglue into the socket without success I removed it (not a quick job) and disassembled it to fix the problem.

With original switches the bottom of the arm is knurled and this provides a firm interference fit into the socket.

BUT. On the repro (as I eventually worked out after some time and swearing) both the socket and the arm are threaded 10/24. Furthermore the threads were loose enough that once it bottomed out it just spun and wouldn't tighten.

So I cleaned out the threads, Araldited it back in place and it now works.

So beware; if yours spins you can just unscrew it from the socket and glue it back in place without having to go to the trouble of removing the switch and disassembling it.

Thanks for posting Andrew

Repro repro….the quality and problems don’t seem to go away…..

265bhp wrote: ↑

Sat Mar 14, 2026 9:10 pm

Repro repro….the quality and problems don’t seem to go away…..

That's because most repro manufacturers have neither the wit nor the wisdom to do the job properly.

Annoying, but unfortunately true.

I have experienced exactly the same problem as Andrew with the C21710 aftermarket indicator switch. It is simply cheap crap. I also started with superglue, but that didn't work. Then I made the thread longer so there was room for a lock nut, as seen in the photo. It worked for 14 days, then it came loose again. Finally, I also gave it some JB Weld epoxy glue. It worked! But honestly, you pay more than €220 for such crap. I have heard that you can use the newer model C25254 as a replacement for C21710 on older cars also. There is probably a surplus wire, but it should be of significantly better quality.

Jesper

C25254 uses the plastic ring to cancel; so you'd need that as well.