Page 1 of 1

15A fuse blowing

PostPosted: Fri Aug 23, 2013 2:11 am
by ericetz301
Hi folks collective wisdom required.
my Mastiff is blowing the main (15A.)fuse as soon as I switch to the side/parking light, I've disconnected the wiring for both front lamps (parking/side) and tail light and the fault remains, bizarrely, I've tried main beam flash/passing button, all OK, along with all other electrical systems, IE, starts and runs, horn, indicator,brake/stop light and passing flash main beam,OK.
Its only when the light switch is used to the first position that the fuse blows.
1, is there any known problem with the switch assy.?
2, are the blocking diodes in the loom/harness likely to cause this problem if they fail ?
any information would be a great help.
cheers Eric.

Re: 15A fuse blowing

PostPosted: Sat Aug 24, 2013 8:04 am
by billr
ericetz301 wrote:Its only when the light switch is used to the first position that the fuse blows.
1, is there any known problem with the switch assy.?
2, are the blocking diodes in the loom/harness likely to cause this problem if they fail ?
any information would be a great help.
cheers Eric.

There are diodes that may be causing the problem. Quick search of the forum found this:
Electrical help for Baggy
I have a Traveller that started blowing the main fuse. The dash light diode was broken and would lose contact intermittently.
Couple of pics in the post.
I had to uncover the harness to find the diode.
Can't speak to the switch, since they're disabled in the USA (I guess we can't turn on our lights without help... ;-) )
Good luck.
Bill R

Re: 15A fuse blowing

PostPosted: Tue Aug 27, 2013 2:24 pm
by ericetz301
many thanks,Billr. :D ........
the culprit was one of the dreaded diodes lurking in the loom, and it turned out to be one over the cylinder as show in one of the pix.
by chance in the box of stuff ``that will come in handy one day``, there was a few diodes of the correct value, new one fitted
all is now working as it should, happy days.
cheers Eric.

Re: 15A fuse blowing

PostPosted: Tue Aug 27, 2013 2:58 pm
by billr
Most excellent :D
Don't know what I'd do without this site as a resource.
Bill R