For the last few weeks i have had an issue with my 150 CDTi Sri.
Leave it overnight and in the morning the battery will be dead, and by that i mean nothing
get the jump leads out and it will start, once the car has been run for a while it will be ok for the entire day, the car is a taxi so it is used for 8-10 hours of the day.
So far we have replaced the alternator and battery, i have measured the voltage once the car has been started and it only reads 13.5V, this surprised me until someone commented that Canbus cars sometimes dont charge at 14.4....i don't know how true that is though.
At night i have noticed that the lights 'pulse' as the revs rise, when the car is at idle the pulsing stops, but when driving down a lane with main beam in it is very noticeable, i would imagine this is down to the alternator, however i don't think that the alternator is at fault, my reason for thinking this is if i disconnect the battery overnight it will start with no issues in the morning.
I have disconnected things that have been retro fitted such as my meter and radio when the car is left overnight. again this didn't change anything, the car will still not start.
I am slowly getting to the point where i think it is a power drain, one of the things i can hear once everything is powered down is a fan of some description, almost like a PC fan, my car has sat nav fitted so i don't know if this has some bearing on the matter, is anyone else able to hear a fan running when they turn the ignition off on their sat nav unit (the fan will still be running a few minutes after the ignition has been switched off)
The only other issue i can see is i get the 'safeguard' message appear every day, i have pinpointed this to a faulty door light switch on the OSR door, it wont switch the light on when the door is open, could this cause the issue i have or are we looking at something more serious?
Thanks in advance