another dash light question

[fireguyfire]

I am going through my dash lighting and have changed all the white lights to LED's; look s great!
While I have the tach out I looked at the 2 turn signal lights (green arrows); they are very dim on my car and one is dimmer than the other.
They are the smaller spade type bulbs but when I remove them from the tach and activate the turn signals both bulbs run brightly as they should, so i thought perhaps the back of the turn signal lenses were dirty. Ran some qtips wet with cleaned in and out of the bores where the turn signal sockets go all the way to the green plastic lenses and both came out perfectly clean.
Has anyone else had this problem? Has the green plastic lenses perhaps gone cloudy? Seems strange that they would be so dim, and especially one being dimmer than the other but not when removed from the tach.