Most members who know about this recommend check maintainenc chargers which cam be plugged in and left to keep the battery at optimal level ready for use. Chidders
Sounds like the fuel filter may want changing or you have an air leak.
would try filter change first and change the seal as well as the first point of call.
Chidders
Had a similar problem with my 2006 S type last year. Had 2 faults leakage from rear water connection on back of engine. Replaced unit at nearly 350 and then heater control unit under front offside head light at 400 now nice and warm after a couple of miles down the road. Just need to say done as 2 separate jobs. Chidders
Definitely sounds like a defective earth on the light unit try a shor length of wire from a known good earth. (Battery clamp to light unit) to seed that cures it. Chidders
Hi Barrie,
I would first of all find the temp sender and remove the wire and try earthing it directly to the engine or radiator to see if the gauge moves straight to hot position..
If so means the sender unit is duff.
dave
I agree with old Peter's Comments.. If you can’t do the 40 minute run you will find that most people on here will recommend the. C-tec charger as the best one to use. Dave