door trigger not working after adding diode

Today I set up everything other than the door trigger because I am facing some diode issues My alarm negative trigger line sends out +4.76v all the time. When I connect it to one door sensor, everything works correctly, and I see it becomes 0v, and the alarm door trigger is triggered. I heard click-click sound from the alarm device. However, all four doors have their own sensor wires. Therefore, I bought four 1N4004 diodes to separate them. After I use them, the door trigger never been triggered. I removed all and use only one diode to one door only, instead of 0v, I see it become 0.7v, I guess that's the reason the door sensor cannot trigger door trigger anymore with a diode in between because the voltage drops by the diode. How can I solve this problem? And can I just connect all four wires to one door trigger wire without diode? thanks a lot!

did you install the diodes the right way? there is a stripe on the end of each diode and for a negative door trigger system the striped side of the diode should be facing away from the alarm brain to allow the negative signal from the door pins to flow to the alarm brain. if you installed them facing the wrong way then they will block the signal and nothing will work