I am trying to reconnect electric baseboard heaters after a flooring remodel. Some of the heaters work after reconnection, and some do not. Does it matter which wire you connect to the pos and negative in the heater's connection box? I connected the wire with the dashed white line to the pos and the solid black to the solid black. Also, when connecting heaters that are in a series connected to the same thermostat, which wires should connect to which?

There is no pos and negative with AC wiring. Is this a 120 or 240 heater? Make sure you wired through the thermostat properly.

When you ask which wire should connect to which we have no idea what you are talking about.
Like ma said, there is no pos and negative. Most likely the heaters are 240V so you have two hots and a ground to the heaters. Maybe double that if more than one heater is off a single thermostat.

http://s57.photobucket.com/user/mojomafia/media/IMG_2498_zps19551585.jpg.html

Here's what it looks like. Sorry I'm not an electrician. It seemed easy enough to disconnect and reconnect, but I guess I messed it up. OR the heater is dead...

http://s57.photobucket.com/user/mojomafia/media/IMG_2498_zps19551585.jpg.html
There is no pos and neg with AC wiring. Is this a 120 or 240 heater? Make sure you wired through the thermostat properly.

http://s57.photobucket.com/user/mojomafia/media/IMG_2498_zps19551585.jpg.html
When you ask which wire should connect to which we have no idea what you are talking about.
Like ma said, there is no pos and neg. Most likely the heaters are 240V so you have two hots and a ground to the heaters. Maybe double that if more than one heater is off a single thermostat.

Stupid pic won't stick... Here's the URL

Heater Reconnect Photo by mojomafia | Photobucket (http://s57.photobucket.com/user/mojomafia/media/IMG_2498_zps19551585.jpg.html)

If that is one cable from the thermostat and one cable to another heater it looks right to me.