check for water ingress in ecu area, most common in the 75 diesel range. water build up causes short inside ecu, also damages glow relay next to it. if this is the case, remove ecu , open it up - 4 torx screws, put near a radiator type heat to dry out, blow dry via hair drier, not heat gun !. you got nothing to loose here these can cost £700 + depending on g/box type. if water is evident then under the ecu in bulk head there is a rubber drain tube , its at the bottom , may need tourch to see it. GET LONG NOSE PLIERS AND TEAR IT OUT! throw it away, area will never fill again. i recommend this be removed in any case , if you have a problem or not. hope this helps.
probey.
August 2008