Roverlike

It is rather difficult for me to advise if I do not know where (to which wires) you attached new electrics and without diagram of how it is connected.

I already answerd on .org ...

Have you checked boot lock once again?

Second thing, horn should not be the one that is triggered by your alarm, but BBUS unit (Batter Backed-Up Sounder). If you disconnect it you should silence the neighbour wakening device.

Plips do not have coils for immobiliser. Coil is on the ignition barrel. Only difference is with 3TXA plips, they will not work on later car alarm systems with coil for immobiliser.

I would suspect your switch. How often do you open passenger window? I would say that contacts on the switch might be dirty.

Actualy yes. Horns on models with two horns use same ground and power wire, so splicing is fine.

I made some tutorials on this topics if they might help you:

1. forums.mg-rover.org/mgf-mgtf-12/mg-f-tf-...ection-guide-866231/

2. forums.mg-rover.org/mgf-mgtf-12/mg-f-tf-...elay-listing-487819/

Anyhow, if you are missing corresponding wire colours from the car (as it seems to me on your picture), the you might want to strip isolating tape around wires deeper in the engine compartment as somwhere there previous owner must joined these new wires to old ones, and there you can find colour wire match.

Dark Ice Design created Red dipstic top, see here: www.ebay.co.uk/itm/Universal-CNC-Alumini...5gok9kZce1EODTdXi2fQ