You have two separate problems, as the dash blinker light circuit is separate from the map light.

The blinker lights run off the round multi-pin connector on the dash light circuitboard. the copper traces on that board weren't treated from the factory and tarnish at the lightbulb connector. also, the pins that the round multi-pin connector are attached to are riveted in place, and they are prone to get loose with vibration and can even break or tarnish around the area the pin makes contact with the circuit board. I don't believe your blinker switch or the steering column connector is the problem because your blinkers work. I tend to think it is at that connector on the back of the gauge cluster.

The canister is as mentioned by another member, your key light timer can. it works on heat.

The map light is part of the curtesy light circuit that can include the console and dome lights. with that circuit, all the lamps have a live positive feed connected all the time. when you open the door, use the dimmer switch or flip the map light switch, what you are doing is grounding the circuit to the body. they are all tied together. This is why when you open the door the map light comes on. The map light has a switch that has its own ground so that you can turn it on while the other lights stay off. Pink energizes the switch and yellow is ground. if you remove the fixture with the two screws that hold it to the dash it is very easy to test for continuity with a circuit tester light or volt/ohm meter while it is still attached.