UK Car Repair: Jaguar intermittent starting problems, jaguar x type, blue spark

Question
I Have a 2004 Jaguar x type diesel, which every now and then refuses to start. It will click when you turn the ignition but not turn over, radio and lights etc working ok. However if i disconnect the positive and negative to the battery and reconnect them again it starts.

Answer
Hi Mark, the smart money is on a loose or dirty battery connection or earth strap. To test for this you need to 'wiggle' the battery connections when you think they are tight, and listen for a crackle (if you do this in the dark look for a small blue spark). This is indicative of a loose connection and you may just need to clean the terminals or replace the terminal clamp. If this does not produce results then add a second earth strap (you can use a good jump lead for this test, when the problem starts, connect a jump lead from the negative terminal of the battery and the other end to the engine block. The closer to the starter you connect it the better). if the vehicle starts then create a more permanent arrangement of this test ( bolt an earth strap in the same place that the jump lead was). hope it helps you - let me know - Paul