No high beams or daytime running lights

It's a 2000 sunfire. When I start the car all is well until I put it in gear.Then I hear a clicking sound from the fuse area (it's the DRL relay) and the daytime lights are strobing on and off about 8 times then the service light comes on. Then I have no running lights. If I turn the regular headlights on before I put it in gear all is well (no service light) but I have no high beams. I replaced the DRL relay. No change. I checked both headlight bulbs with a battery charger to test the high and low filaments in each bulb and they were OK. I noticed that when the key was on that all 3 pins going to the headlight bulbs were hot with 12 volts. Is this normal? I'm used to a ground and 2 hots (high & low beam) on my other cars. With the key off I turn the headlights on and have no high beams. Any clues as to what I'm missing???

Maybe looke at the emergency/park sensor. As if its in park will not allow DRL to be on, and maybe broke or stick explaining why not woking since you have replace the relay.

As well soem vehicles have 2 relays, one at the cluster(dash) and you coudl also be looking at a short or broken wire.

Could be a bad dimmer switch.