SIM800l completely goes off once I connect my arduino nano to it

I have a sim800l that is working fine until i connect it to arduino nano pin 2 and 3 using softwareserial. Prior to this the sim800 can register itself to a network and i can even call the sim number in the sim tray but once i connect to the nano, the gsm module blinks thrice for like three times and then stops blinking totally and without blink again until i disconnect the arduino. Pin 2 on arduino was tx and 3 was rx. While troubleshooting, I noticed pin 2 and 3 are both on about 5v. is this normal, is the 3 that is rx suppose to be also high. What could be the problem, could be nano be bad. Any suggestion?