electrical fault any ideas ?

hi when i switch on my side lights (mondial 1982) with the ignition off, the fuel gauge goes up and the windscreen wipers come on continuously, untill i switch the stalk on and off again,? any help would be great going to strip out the looms under the dash tomorow

 

iam a uto electrician for volvo trucks, but even if i give the gauge a ground it still goes up,also the wipers only start about 4 secs after yuo turn the side lights on, but thanks anyway chaps, iam just going to have another go with my fluke, wish me luck i think i will need it

 

found a bad reair on the board,repaired that ,now i find the when switching the side lights on wipers dont go straight away (great ) until i then turned on the ignition, s--t the wipers startted again, can anyone point out the major earthing pionts please,i found the one under the wiper motor,in the pass foot well,on the upright by the battery,and a double lead on the fuse board in v plug i think,thanks

 

yes i bought a workshop manual with suplement wiring, and have gone through the wiring diagrams ,and put the relay and fues allocations right