I have a 3 way switch in my home and garage to turn on and off the garage lights, I think I may have a wire on a wrong switch screw. When I come in the garage I can turn the lights on and when I come into the house I can turn them off, only problem is if I'm outside and try coming back in the garage the lights won't turn back on, I have to go back into the house and turn them on from there. Inside the house and garage I have my black hot wire on the black screw of the switch where it should be, could I be having this problem because I have the red and other black wire on the wrong screws, if I swap the red and black wire (blk going to my lights) around will this correct my problem?

 

There is no set color that goes on the common terminal.
When you replace 3w switches.... label the common wire. The others are unimportant.
With two black wires and one red wire... the common will be black.

The red and black traveler wires will go into the same cable jacket.
The odd black wire is the common.

 

Three ways switches I've always been bad with, replacing isn't a problem but on a new service I always seem to forget what goes where. I used the diagram below for a wiring guide, my electrician said I should have connected the blk feed 3 wire and the the blk 2 wire going to my lights together then connect it to the blk screw with a pigtail. Am I'm using a wrong wiring diagram?

 

Hard to comment on. You said you had three wires.
If there are splices involved we'd need to see a picture.

If you are going by the left picture.... do as I said.... the red and black in one jacket are the travelers.
The remaining wire is the common screw wire.

If you typed exactly what your electrician said.... he's wrong. You can't connect the feed directly to the lights. Then the switch would not do anything.

 

Tomorrow I'll pull the switch out, check the wiring again, and post a picture, thanks

 

Pulled the garage switch out which would be the picture on the right, found out I had the black wires on the wrong screws, I switched the wires around just like it shows in the picture and everything works good now. Thanks for all the help!