Hi, i have a 1997 110 300 tdi, recently it has been cutting out whilst driving, mainly on longer journeys , doesnt seem to do it on short hops. I have got new fuel filter. Doesnt slowly die like a fuel starve just cuts out. I then turn off ignition, wait for immobiliser to arm, then cancel immobiliser and attempt to start, this may take several goes to start engine. Also arm and disarm alarm manually. Whilst driving with lights on my red alarm light constantly flickers even when i have switched alarm off prior to starting. For a long time i have noticed when i turn lights on my fuel gauge reads higher! + heater fan blower dims lights and also with lights on wipers work slower! Hope this is as clear as mud! Please help!!!!!!!!

try checking all your earthing points it could be that simple

Thanks for that, I will try and find them all!