4 wire onnector under fuse box?

[goodjuan]

I'm in the middle of an sr swap in my 90 coupe and I can't figure out what the 4 wire grey plug connector is for UNDER the fuse box (by the batt) is for.

The lower harness, from the SR, plugs into everything else BUT that connector? Does anyone know what that plug is for? :bash:

Thanks
GoodJuan/OverZealousNoob