NO SPARK FROM COIL IGNITION LEAD

Hi guys can someone help me please i have a mk1 clipper KReg  something strange i fitted a stereo the other day and before i did it car run fine 
So heres what happened unplugged old stereo plugged in new one worked for few seconds then went off now the stereo wont work off ignition live but works fine off perm live so i thought i would seek advice by a friend so went to drive car but now it wont start grrrrrrrr.
Car is turning over when i checked coil for spark there wasnt one from lead to dizzy  but i have 12v in the coil my friend checked it with his tester when he fires 12v down lead and i turn key car starts strange it mite not have anything to do with stereo but just seems a cow incidence  does anyone on here know what it could be its really bugging me now my mk1 has always started first turn of key 
Please someone heeeeeelllllppppppp me 

check all the ignition switch wiring, the black one is what gives the coil 12v.  if the wire looks ok try bridging the red to the black, this should give you live at the coil. if that works replace the ignition switch, if not dig into the wiring more.

the factory ignition live isnt fused, but if its had an alarm or immobiliser fitted this may tap into it and the stereo could have blown an alarm or immobiliser fuse?  either that or the coil has been bodged into some other ignition feed on fusebox. off hand check fuses 17 and 18

Ok i will have a look when i get home later thx for the reply mate

Fuses 17 and 18 are ok mate grŕrrr  in fact all my fuses are i will have to get my mate to check wires not my strong point got to be something stupid mate

I have the same problem! I fitted a subwoofer to the golf and it worked fine for a while and then it started cutting out, and now the car won't start! It cranks but won't turn over. I don't know what is wrong with it but none of the spark plugs are firing!! any help would be appreciated.

Ah atleast im not on my own thought i was going mad lol is the syetep still ok mate 

the stereo cuts out when its loud... i have no idea what is wrong

Jonny do you have wiring diagram for 1993 mk 1 clipper 

I have sorted my problem! this might not work for you but what i did was remove the stereo and unglug the remote cable, and then find any exposed wires behind the dash and tape them up to make sure they aren't touching anything, this might not work for you but i think my sub was vibrating the wires and grounding them  

From what i found tonight mate looks like ive got faulty ignition switch  if i cut out ignition all together  and fire 12v with tester it fires from coil and also fires from starter but if if i turn key car turns over but no spark then if i fire 12v down ignition wire from ignition switch car starts lol

the closest i have is jetta89 in my sig, its same fusebox so mostly the same wiring. the ignition switch etc all same so fine for your needs.

brown haynes manual has the right diagrams tho, i woudl recommend you get one

Ah mate ive ordered new one from vw heritage.
 Incase it didnt work is there a relay in fuse box that controls spark from key ignition switch 
All my fuses are good  but i guess if its works when he fires 12v down it it cant be a relay because its passing through and firing lol confusion  lol 

yeah therte is no fuse or relay fior the coil, its fed direct off the ign switch black wire via the fusebox.

if when bypassing the switch and putting 12v down the black wire your car fires then that tells you the switch is bust

Thanks mate all you info has been a big help over tge past few days really appreciate it mate thank you