Turn signal bulbs new. It blinks fast on the passenger side and clicks with this part vibrating. When headlights are on the turn signal arrow for the passenger side is solid. When I hit my horn the passenger side turn arrow turns on.

 

Need to know what vehicle we are talking about here and what we are looking at.

 

2000 Dakota 4.7L sport 4WD quad cab and do not know what this is called but I would like to know so I can replace it

 

Bad ground. Or bulb with a broken filament across the other one.

Moving this to 2nd gen Dakota section for ya.

 

As to hitting the horn making it turn on does the ground make that happen. Because I thought It was a ground but then that happened once putting in bulbs finally after 2 years never seen a turn signal turn on with the horn button pushed

 

That is a strange one. Not sure if they have a common connection somewhere, or not......

On my truck, there was a selection of grounds on the body, just in front of the battery, way down deep..... several of them are pretty small wires, and they had corroded/broke.... which game me a lot of intermittent problems.... That was a fun one to troubleshoot, and the shop I had it at couldn't figure it out......