I have been doing some painting and light remodeling. Part of my project is changing old switches and receptacles.
Yesterday I changed 2 old 3 way switches with 2 new "lighted" 3 ways for a hall light. After I was finished I noticed the florescent bulb had a almost unnoticeable, low power flash about every 3 or 4 seconds. Also both lighted switches had a very small flicker. I tried several changes and finally took a diagram for 3 way switches and started over. I'm positive I have it wired correctly, I even changed both switches again. Desperate to find what was wrong I changed to a new florescent bulb, same issue. Finally I put in a incandescent bulb and the switch and bulb flickering stopped.
There wasn't this problem until I changed the switches to lighted 3 ways. To confuse me even more I have the same lighted 3 ways in another location and the fixture has 3 florescent bulbs but they don't flicker. They are wired exactly the same. What's the deal? Anyone have any ideas why it is doing this?

 

Not a stumper but to be expected if the switch does not have a neutral for the light. No neutral means it draws its power to light through the light fixture and that is enough current to flash a fluorescent. No neutral lights switches are intended for incandescent lighting only.

Two fixes: Simplest, add an incandescent light to the mix. Best use a switch that has a nutral for the light function but that will only work if you have a neutral in the switch box.

Is there an incandescent light also? Do those switches have a neutral? Are the ballasts the same or is one a magnetic ballast and the other electronic (or do you mean you mean CFL bulbs)?

 

The new switches have a grounding screw, the old did not. There is a ground in the box, 3 all tied together but since the old switches did not have a ground screw they were not connected. Is that what you mean by a neutral? The new 3 ways have 3 connections not counting the ground. 2 travelers and one common.
These switches operate only one light. The fluorescent I was using is self contained, there is not ballast otherwise, it's just a standard screw in socket.
I have to wonder why the old switches operated the fluorescent bulb without an issue?
I sooo appreciate your help on this!

 

EDIT: Reread you first post and see you have already tried an incandescent and it proves what I have been saying.

A ground is not a neutral. Why one works and the other doesn't is hard to say. Just as a test try an incandescent either conventional or halogen and see if the blinking stops.

Technical info:
What is a neutral: It is one of the two wires that make up you 120 volt electrical supply.
What is a ground: It is a safety path to trip the circuit in case the neutral fails and you have a short.
Exception: By code a ground can not be used as a neutral but there is one exception which sometimes applies to lighted switches. If the light draws 5ma or less a ground can be used as a neutral but it doesn't appear that applies to your switches based on what you have written.