Automatic light

I have a Dakota 4x4 year 2000.
The lowbeam comes on automatic when I start but not the taillights, which I guess that´s how it should be. Somebody told me that it is possible to disengage this function by disconnect a relay.
My question is, which relay and where do I find it, does anybody know?

under the hood on the left behind the battery there is a black square box with either a 10 or12 way connector this is your daytime running modual and if you disconnect the harness from the modual your daytime running lamps will be disabled and you will also loose your high beam indicator but if you cut the white with a black tracer wire at pin 4 from the harness and ground that wire going to the modual your daytime running lamps will be defeated and your high beam indicator will still work this fools the modual thinking your park brakes are on but remember you have to open the wire or your warning lamp and abs lamps will stay on in the cluster