I used L293D H bridge to drive 2 dc wiper motor (each 12 v, 2 amp) ]. L293D got heated abnormally. when both connections with motors are made, both the motors didn't operate. However, when one is connected and other is removed, the connected motor then operates. what is the remedy for this problem despite using the relay? Please help.
The L293D apparently can't handle this much intermittent if not continuous loading from both motors and might be shutting down automatically. If one motor is fine, just use two L293D, one for each motor. OR there is the L298 chip, also a dual-H bridge driver, higher voltages/power capability, which might drive both your motors just fine.
DHM.
Even one motor is wa-a-a-y over the "Absolute maximum rating" of the L293.
You need to shop for something else (like the L298).
Note that the L298 doesn't have the built-in protection diodes like the L293D. You'll need them for driving motors.
You'll probably also want to add a heatsink: the L298 wastes a lot of energy because it uses Darlington transistors.