Williams Solved Grand Prix (Williams, 1976) PLZ HELP W/ GRAND PRIX!!

[new_pinhead]

plz help w/ grand prix. I removed both pop bumper coils and removed some of the windings to boost power. re-installed just as they were. now as soon as I start a game the right bumper coil energizes and stays energized. the contacts were just as they were when I removed them, but I have tweaked and adjusted them several times comparing to pic I snapped before removing and to left bumper contacts which not having any problem with. I've attached 2 pics of bumper coil and contacts in question. anyone have any idea why I am having this problem? thanks, Phil.
oops, found wires touching . problem fixed. but, do still have problem now with left jet bumper won't activate. Phil.

 

[faralos]

do a solenoid test on it
see if the left flipper activates at all
but that short in the right one may have blown the fuse for the left one too
also you didn't specify which Grand Prix you own
but go here and look at the manuals for of them
they should list solenoid testing in the manual
http://www.ipdb.org/search.pl?any=grand+prix&search=Search+Database&searchtype=quick#5647

 

[new_pinhead]

sorry. Williams 1976 EM Grand Prix. Left jet bumper stopped working.

 

[new_pinhead]

fixed

got it working. I unsoldered the coils on both jet bumpers to switch them and resoldered wires and now both are working. and popping much better than before since I removed some of the windings. must have been a bad solder job on the left bumper wires that had it not working. Phil.

 

[pinballdaveh]

i have removed coil winding layers on gottlieb and bally bumpers and slingshots. i read an article on this that said remove a maximum of 4 winding layers any more than that the resistance will get to low and become a short and the coil will have to be replaced. i remove 3 layers and have had good luck with that. wire insulation has to be removed with a razor blade knife to resolder cut wire to lug. i havent tried this on williams em dc coils yet, but i see now that they can be made stronger. this mod is only for em machines, for em flipper coils a higher strength flipper coil are availible from pinball resource. if you try this mod on ss machines driver board damage may occur but dont know for sure.