I just went down the same road today. Tach stopped, then blower motor. I took out the overload relay and I can hear something rattling inside.

Apparently we have the "euro" version with only four pins. I have a new 50 dollar five pin overload relay. Like yours, it will not fit. They don't make the four pin version anymore.

When you extracted the extra pin did that work in the long term? I've got the new one here and was thinking about doing the same thing.

Thanks!