I have a 1992 chrysler labaren convertable that the left and right signals sometime work and sometime not. The flasher does not work either if the signal is not working. It does not seem to be a weather, rain problem either. HELP I have checked all fuses and the flasher which are fine.

There has to be a short or a loose wire someplace near that flasher unit that effects it. If the fuse is good and the flasher unit is good then there is a short in a wire. You'll need to start tracing them. The other option is possibly the Turn signal control but since the 4 way flasher control is a separate switch or button that pretty much only leaves the one solution, a short.

This may sound silly but try changing the bulbs even if they're good. The pressure from the springs on the contacts in the sockets and the vibrations from the road sometimes wears away at the contacts on the bulb until they no longer make reliable connections. When your front bulb goes out your inside blinker light will not blink, when it's your back bulb it doesn't light up at all. This is a way to tell which bulb is bad and allows you to still manually use your back blinker if the front bulb is out.
The only other possibility that I can think of is damaged wiring to the back lights. Check closely for bad ground wires off of the rear light fixtures.

The turn signal switch is most likely the problem,it is all tied into together.Look for a bad connection,then if there is not a bad connection at the turn signal switch,replace it.

Typically, your symptoms are caused by a poor ground connection. These connections, once corroded give the hit and miss service you are describing. If you are into self-repairs, trace the ground wires back to where they are bolted to the frame. Remove each ground wire, scrub it up along with that spot on the frame, give it a squirt of electrical contact spray and reconnect it. J.