Hi,
I have a disco 300 thats become been a pain to start. The old owner said to always turn on the glow plugs twice before starting.
Been trying to find out why it always takes ages to start when cold , but always starts when hot.
After noticing that glow plug #4 was pumping up and down when the engine was on I replaced 2, 3, & 4 glow plugs. Cant get to #1 easily.
Then have put a meter on the glow plugs and noticed that there was no voltage when the glow plug light was on in the dashboard.
On the timer relay under the bonnet (PRD 6913) there was no voltage on the Orange/Brown wire which is supposed to come from the fusebox or battery when ignition was off.
Have fixed up a wire from battery to the terminal on the Orange/Brown wire under the relay, and now when glow plug light is on the glow plugs actually get a feed from the relay, but, when the engine has started and the glow plug light is off in the dashboard, there is still a feed from the relay to the glow plugs. This stops when the engine is turned off.
So, could I ask you all , should there be a voltage reading on the glow plugs after the engine has started, and the glow plug light has gone out? Kept a meter on for 30 secs and there was still a reading on the plugs while the engine was on.
At least the glow plugs are actually warming up now, so the acid test will be tomorrow morning in the freezing cold !
So, is the relay faulty or is this a normal feature?
Many thanks for any help you can give me.