Dog walking trouble. Help?

My dog, Connor, used to wear a Halti while walking. He walks nicely, almost perfectly, but he gets excited when he sees other dogs, so I make him wear it so I don't have any troubles.

But people always think he's wearing a muzzle, and that he's a dangerous dog because of it, so the other day I bought him a non-pull harness. It does the same thing as the Halti, except it doesn't look like a muzzle.

I introduced it to him. First, I let him sniff it (he mistook it for a toy, and tried to tear it apart), then I gently put it on him, gave him some treats while doing so, then I took it off. Then, about an hour later, I put it back on him and got some treats, and got him to do all of his tricks to make sure that he can move around in it properly. Then this morning I took him for what was supposed to be a quick walk around the block while wearing the harness, but he refused to walk. I had to drag him half of the way. I took him for another walk this afternoon, and he did the same thing. But this afternoon, I brought treats with me and gave him one whenever he walked beside me (which wasn't that often, which is strange for him).

What can I do to stop this? I don't like dragging him, I want him to see the harness as something positive. What can I do? Did I introduce it right? Did I do something wrong? What can I do about it?

Please help!

And be polite.

Impolite answers will not be chosen as best answer.

Also, he has worn a harness before. When he was a little pup, I walked him with a harness (only because he looked so cute in it) and he was fine with it. He also wears a harness in the car, because here, the law states that a dog has to be restrained by either a harness or a dog seat belt while traveling in a car. I don't know what the problem is with this one, though.

Thanks.