Started By: Ray Suchta on 2008-07-22 15:35:30

I have a 67 Mark 2 which is blowing the 50 amp fuse. Any likely suspects?


Rat how about a little more information--does it blow when you put it (fuse) in or does it blow when you use a certain function (horn etc.) That is a heavy use fuse but in an easy place to isolate the many wires going to it. Remove all leads to the fuse and try them one by one--when the fuse blows trace that wire on the chart--to blow a 50 you have some sort of dead short!

Sorry I meant Ray not Rat--too early!

Good advice, but I recommend using clip leads to install a 12 Volt light bulb in place of the fuse. The light will be on when the short is present. Disconnect each wire and see which one makes the light go out. That should point you in the right direction.

Mike that will work too. I ues micro circuit breakers or a precise power load bank but I thought with where Ray seemed to be a hand full of fuses and a screw driver might be good for his first leason!

George and Michael,
The fuse blows when I turn on the ignition. I thought about a temporary jump circuit with a handful of fuses but the light bulb sounds like a winner. I'll give it a try! Thanks for the good advice!
PS my local foreign parts store has some of the original Lucas type fuses with the paper in them, but he is hoarding them.

you can get those original type fuses at any Jaguar dealer, so I don't see the point in hoarding them. They are not "rare" nor NLS.

Michael and George, I found my short. Last fall I had to unbolt the wiper motor from the fender. When I reattached the motor a saw a black wire attached to the fender. I attached it to the wiper motor housing. That's what was blowing the fuse. Disconnect the wire from the wiper motor case and no blown fuse! Now I have a goriunf wire going nowhere and now the wipers don't work. I am sure that wire is used as a grounf for the wiper motors but can't see where. I have the wiring diagram so i can check connections but 40 year old wires are dirty and colors are difficult to discerne. I may have broken a wire when I unbolted the motor from the fender. Any suggestions?

Ray congrats on finding your short! Wiper motor wires do loose color quicker and it seems it is because they are a smaller gauge.. but you should see that the motor harness has a protective PVC cover that can be carefully cut back to see fresh wire color! If you sort it out you can repair your cut with shrink tube and if you do it carefully no one will know. Sounds like your short might be internal for your motor does need a ground and it does attach to the case. Have you looked at the diagram on the motor in E 121/7 (the MK2 service manual) page P37 (in this vol)? I think if you do you will be able to sort it out as it is a very good section. Good luck. BTW based on experience only I would start with the park switch or the thermal overload switch (both inside the motor)> Geo.