Just connect a pair of jump leads to your battery , clamp the earth lead to the thread of the glow plug and clamp the live to the top small threaded part of glow plug and they should start to glow in around 3 seconds and keep glowing more and more . if they dont glow they dont work ! a good way of telling there not working is that the glow tips are black and sooty where as working ones look burnt :smiley:i always fit dealer ones as champion , ngk etc etc dont seem to last long