1995 jaguar XJ12
 

i have a 95 jaguar xj12, this vehicle is my bosses wife's car and has been a problem for this shop for too long. before i started working here the car has had an issue with intermittent no cranks, when this condition is present none of the interior lights that are controlled by the BPU work, as well as the WCA's fail to come on. the trunk lights will not come on either, this was a condition that seemed to be pretty cut and dry, its got a bad BPU rite? well thats what i thought so i replaced it and lone behold it was not the cause, before i started the shop owner and tech replaced the ECM, security module, BPU rebuilt the transmission. was wondering if anyone has dealt with this before, the conditions are no crank, no interior lights, no WCA lights on IP cluster, no trunk lights and no sound emitted from speaker to indicate key in ignition or driver door open. it sounds just like a BPU but we are on the 3rd one now with the same condition. i would scope the com network but it is k and l line so finding any sort of pattern is more or less out of the question