K8023 output problems

Good morning everybody
I have built de K8023 kit . 2 channel 2 wire remote control
It seems to be working properly but I am not a technician and now de current activated in each output is very low (0,6 V)
Example … activating switch COM+1 ON P8023S makes appear voltage between GND and 1 on P8023R but very low , only 0,6V
Questions…
1/ Is that correct.???
2/ What type of relay may I use to in order to connect a 12V 5A output ?
Thank you very much in advance for any possible help