I think my cpu unit is faulty the car is a 1993 xj6, I am having problems with some lights and windshield washers. I have swapped all relays wit good ones from another car, and no improvement. the only item i have not tried is the cpu as mine has a number of DPP 1056 and the one i can try is a DPP1131. I dont assume they are interchangable,but they have the same fittings.Have any body swapped the 1131 for the 1056 (they may be the same but if not i wouldnt want to fry the one i can borrow. thanks in advance Lummpy