Glow plugs

[Scot the sniper]

Hi all this is a long story sorry.ok here goes I fitted glow plugs in a 56 plate Passat 2.0 about 3 years ago not ones as said on a forum about 2 days later the engine management light came on I plugged in and it said glow plug 1 fault 2 fault 3 fault 4 fault so told my friend it could be wrong plugs but it started fine so 3 years down the line he has bought a new car and gave this car to me so I took rocker cover off took out the plugs and everyone goosed I thought strange but on my snap on machine it says there is a short on everyone testes them right enough goosed so then got me test light and tested every wire that goes to the plugs all ok there so I was puzzled I have bought main dealer ones to fit in still racking my brains so next step with tester was see if the light is going of so in with the tester again switch ignition on glow plug light in the car goes off but at the wire end it came on bright for a sec and light dulled down but never went off cant see this being normal any ideas anyone else had this and how did you fix it