4 channel relay

I'm currently working on making a simple sequencer for my traffic light, and when i run my program, the first two relays work, but the third relay clicks louder than the other two and the light doesn't go on. when i unplug that relay input from the relay board 'in3' all three lights sequence fine. is there a specific reason why this is happening?

We don't know how you connected it. We don't know what relay module you use. We don't know your program.

=> So we certainly don't know the answer to your problem...

For connections, check out this method.

I'm currently working on making a simple sequencer for my traffic light, and when i run my program, the first two relays work, but the third relay clicks louder than the other two and the light doesn't go on. when i unplug that relay input from the relay board 'in3' all three lights sequence fine. is there a specific reason why this is happening?

I really don't know how you expect us to answer a question like this with absolutely no information. We don't have a crystal ball. This is the General Electronics Topic. (not Psychic Medium)

If you post on this topic, in addition to your description of the problem , you are required to provide some documentation for the circuit and sometimes the code. The circuit documentation can simply be a photo of a hand drawn schematic, or worst case a Fritzing (which we hate by the way). The S/W is the code, but is not always necessary. We look at the circuit documentation and then make a judgement as to the relevance of the software. Obviously , if we see a miswire that explains the fault , there would be no reason to ask for the software.