I replace a regular switch with a timer switch for my porch light- the new switch is w/o a neutral wire. Once installed it works but when it's in the off position the light is still on but very dim. I figured I put the black wire connection backwards- so I switched the two black wire connections- same result. The timer works- the on position works- but it never fully goes off, just dims in the off position- what went wrong- inside the wall box are two black wires and a ground- the switch has a black, a blue and a ground. Help!?

if installed in accordance with the manufacturer's instructions, then this question should be brought to the manufacturer...

It's stormy outside tonight and TV is boring so let's try a few things.

If it is an electronic timer- digital and not a mechanical timer, then it probably is faulty, but sometimes the electronics need a ground reference to completely kill the current through the switching device. They may also need a certain load impedance to pull down the switching circuit. Make sure your ground is good and that you have read the manufacturers instructions. What type of bulb are you using in the light? If you aren't using an incandescent light just try one for the heck of it. An LED light or CFL bulb might not have enough load on it to work correctly with the switch where an incandescent might. All else fails take it back and ask for a new one or your money back. If you bought it from a source that has technical people working there, you might ask if they have had this issue before and what they did about it. I would be interested to find out the reason for my own information. I install these devices now and then and I haven't ever had your issue, but it only takes one different variable sometimes to change the way things behave.

I have had other devices that use similar triacs (electronic switches)etc. on the outputs that needed a pull down or bleed resistor to completely kill the power or they will leak a small current depending on the device connected to it. That is why I suggested the regular incandescent lamp idea in hopes it might work. If you figure it out please come back and let us know what you found.

Thanks Studs ad- you hit it on the head- first the journey- I first installed electronic timer switch with no neutral wire- light only dimmed but didn't go off- I replaced that one w one that had a neutral and that fixed it! But I had a second to install- two lights on this switch- this switch had no neutral so I used the original timer switch I bought and the same thing happened -it dimmed but didn't go off - I WAS using Led bulbs- so I tried your suggestion and replaced only one w regular bulb- and the lights went completely out- Funny that it only took one bulb to do it- I did however switch both to regular bulbs so they'd match and now my lights are off when they should be- So... my conclusion is this- if using Led bulbs you need a timer switch w a neutral wire connection- and if you have no neutral you can't use Led bulbs!

THANKS for the help- appreciate being able to figure it out w/o calling an electrician!