I have a Dacor single wall oven. Lately it seems to be having issues when I choose baking it randomly switches over to broil. I was baking a cake the other day and when the cake was almost

SOURCE: OLD GE Wall Oven doesn't heat properly

On these older ovens ther is usually always 120 volts on the elements at all times.
If you check across the element ends with it in bake you should read 240V. If not, there is a problem with the control. With the voltage drop you describe, it sounds like you are losing power on one line of voltage coming to the element.
Post back to let me know what you find out or if you have any questions.

SOURCE: Dacor Gas wall oven

is there tension on the door at the point where it doesnt seal,is the spring broken/missing,when the door opens and closes is there enough travel from point a to point b inside the cabinet on both sides of the hinge area, is the sping loaded mechanism damaged .

SOURCE: Dacor double oven ecd230 -- bottom oven won't heat

check the ignitor.

SOURCE: Dacor Wall Oven won't heat - Cannot find thermal reset switch

Open the oven door and unscrew the vented panel at the top. Make sure the oven is off. Atop the electronics in there you'll see a little red button. Push it. Voila.

SOURCE: My Dacor wont heat, broil or convection after self cleaning

like another person stated-from the front behind the door, take off the 6 screws and the cover by the latch. there is an "oven hi temp limit switch" It is crome with 2 heavy black wires connected to it. On the back side of this is a small red button which will reset the limit switch. I had the same issue (everything worked except the any of the heating elements) and quickly resolved.