They have two horns 1 either side they may hav packed up unlikely both at same time but if only 1 was working before then it cud be horns themselves! Check power to them and the click you can here is the relay in fuse box in engine compartment! Not sure where 2wd are but on a 4wd above the pass glove box there's a tray you need to pull that out and check that the multiplug behind is pushed in to the unit properly this may cure your door check problem! There's also a unit for your light check behind drivers side of bottom part of dash this may be ur problem for light on when head light is actually working and also check you have correct bulb fitted!