Unused / Empty / Disconnected Electrical Connectors

[Jukebox45s]

Hi,

I have three unconnected electrical connectors under the hood. Photos attached here.

Does anyone know what they are for? Should they be connected? Are they for optional extras that the truck is not fitted with?

The circular white one - with the three lugs I would guess is an old aerial connector - but posted it here anyway - just in case someone knows different and can correct me.

The pickup has ABS - I only mention this as someone else thought this may be related to them.

Thanks for your help - the truck is in the UK - so local mechanics don't know.

Chris

 

[Jukebox45s]

There is also this spare connector. Sits under the hood beneath the windscreen on the passengers side. This looks like a relay holder? Currently the hazards do not work - but the relay for these sit in the cab fuse box and a fuse for them is in the fuse box under the hood - both of which are good/new . Can anyone help with identifying what this may be for? Thanks

 

[Jukebox45s]

I have discovered that the blue ringed connector and the flat white connector are for the towing electrics and electric brakes on a trailer. I still have yet to discover what the relay holder is for? Can anyone help?