Install a relay, like the factory should have in the first place.
Another option is to do like I did with my Milwaukee Sawz-All when the pitman assembly broke. The service depot said parts no longer available. I said what model superceded this model? What's different on it? All the cases were the same - the motor was the same, but the entire piman assembly was different. Same case. Whats stopping me from putting in a whole new pitman assembly? I needed about 3/4 of it anyways - so the additional few parts to update to the new system ammounted to a few bucks.
The switch from a newer model may fit perfectly - or may require modifying a connector, or simply using a longer screw (I've had that happen too)