Okay. I have been playing the relay i have at the mo. When i turn on the ignition there is no voltage to the glow plugs, however i know that there is voltage going to the relay, One permenant and one switched. I suspect the relay is fooked, so i thought i'd just double check everything so:
Whilst the engine was running i put the volt meter onto the glow plug wire and had a voltage of of approx 12.5v, is this something to do with the cold starting and would switch its self off after a short period, or does the feed to the glow plugs stay on all the time?
afaik it shouldnt stay on all the time because your glow plugs would burn out thats what the relays for to turn them off.
when i had heated'elec seat wiring put in garryD made me a little loom as i had none of it in the car this had a relay with the wiring, when i put seat on it got hot stayed hot for so long then knocked off. If iwanted heat still i would need to turn the switch off then back on the glow plugs should work in this way too.