Voltmeters? Doubt he has a voltmeter as he's probably new to RC.
Check if both your transmitter and reciever are on, and all the wires are fully connected.
Check if the JST plugs (3 pins, i.e. 3 wires usually red black and a white.) that come out of your esc is facing the right way, and in the right hole. (channel 1 for servo, channel 2 for esc. and auxiliary output for the +/- leads if you have em.)
Check if the crystals on your Transmitter and reciever have not come loose and are of a matching frequency.
Check if the positive and negative wires coming out of your motor (that connects to the ESC) are connected properly.
Check whether all the solder joints are still intact by pulling lightly on each of the wires and seeing whether they've come off. (rather unnecessary, but shit happens, right?)
Then reset your ESC
1. Turn on transmitter and reset ALL the trims to NEUTRAL
2. Turn on your car, if the beeping continues then Redo the checks stated above ^.
3. If the esc turns on, press and hold the esc's reset button until the light comes on ONCE and the ESC beeps ONCE. (the esc will continue to flash continuously until you do the next step. example = 0 - 0 - 0 - 0 - 0)
4. On your transmitter, Pull the trigger into FULL THROTTLE.
Then press and hold the esc's reset button again until it beeps again. (This time the number of flashes will increase to twice. example = 00 - 00 - 00 - 00)
5. On your transmitter, push the trigger into FULL REVERSE, and press the esc's reset button once again. Now, the esc's LED should not blink at all and your car should do what you want it to, provided you're using the transmitter, of course.
After having done all these and nothing helps, something's probably spoiled so get a friend and test your electronics one by one on HIS car. If one lone piece of electronic doesn't work, then you have the culprit. Proceed to bludgeon the p.o.s. to a small pile of plastic granules then melt the s.o.b.
and create a sculpture in it's honour.
Just my 0.2c worth. Quite alot, huh.