A field is not search even after providing weights

[shankarps (Shankar)]

I have an index with the following sample vehicle data.

"_source": {
                "Type": "Van",
                "Year": 2016,
                "YearStr": "2016",
                "Make": "Ford",
                "Model": "Transit",
                "ColorDesc": "White"
            }

When I run a multi field search with same weights for Make, Model and YearStr like "Ford 2017", the search results match the Ford make, but does not select the records with the Year = 2017 first. It matches all years (like 2016, 2017, 2018, etc) in random order. They all have the same score.

Why do the records that have the year = 2017 not have a higher score? If a record has Make= Ford and Year = 2017, shouldn't it get a much higher score than one with Make= Ford and Year = 2018, since the Make and Year can boost the scores?

The query I send is this ->

{
  "min_score": 20,
  "query": {
    "multi_match": {
      "fields": [
        "Make^25",
        "Model^25",
        "YearStr^25",
        "Type^20",
        "Color^15"
      ],
      "fuzziness": "AUTO",
      "operator": "or",
      "query": "Ford 2017",
      "type": "best_fields"
    }
  }
}

Thanks for reading. Any ideas will be helpful.