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Ooops... i've blown a fuse

Posted: Sat Sep 25, 2010 5:14 pm
by Inverted
Hey everyone,

Being a newbie i'm bound to make mistakes, and heres one of my first! I've replaced the indicator arm on my 65 saloon today, however, i've managed to create a short somewhere, so its blown one of the 35A glass fuses when i tested the horn (the left hand one when looked at). I think i may have an idea what i have done but if someone could back me up or correct me on my thinking it would be much appreciated!
The old indicator stalk was missing the copper/brass contact block...

Image

the new arm has one, and not reading any books etc, i believed that the contact block should make contact with the brass looking collar that surrounds the column just below the spring mechanism for the horn. My thinking for this was because it had scuff marks around the collar. Could it be this thats shorting the circuit when the horn is pressed? Should the contact block sit below the brass collar? or should i remove it as per the old stalk??

Chris

Re: Ooops... i've blown a fuse

Posted: Sat Sep 25, 2010 5:38 pm
by MarkyB
Did the fuse blow when you pressed the horn button?

The horn is live all the time and pushing the button earths it to create a circuit.

My guess is that you joined a wire carrying 12 volts to the connection that should have been for the horn.

Most things are earthed and work when 12 volts gets supplied.
No idea why the horn is the other way round.

Re: Ooops... i've blown a fuse

Posted: Sat Sep 25, 2010 6:59 pm
by simmitc
The pad on the switch should indeed be in contact with the brass collar around the column, that's what allows the horn to work. The problem is likely as above.

Re: Ooops... i've blown a fuse

Posted: Sat Sep 25, 2010 7:12 pm
by Inverted
Thanks for the comments!
I've just been down to have a play.... i've replaced the 35A fuse, removed the wheel, and examined the new stalk again. Yup the new pad is in contact with the collar (thought that must be the case!) no idea how the old one was working though! I only replaced it as the arm was heavily corroded. Put it all together again, and hey presto... works. No idea why it blew the fuse in the first place however.I assume the horn blew the fuse as we were out and about today and i tested the horn to find it stayed on for 10 secs or so. Then didn't work after. All the electrics are fine now (he says).... :roll:

Regards
Chris

Re: Ooops... i've blown a fuse

Posted: Mon Nov 22, 2010 8:29 pm
by Dave36
fuses in a Moggy??????????????
not seen any yet.....................

Re: Ooops... i've blown a fuse

Posted: Mon Nov 22, 2010 8:55 pm
by bmcecosse
2 in service + 2 spares!

Re: Ooops... i've blown a fuse

Posted: Tue Nov 23, 2010 8:05 am
by mike.perry
bmcecosse wrote:2 in service + 2 spares!
Plus 1 in line fuse for lights on 1098s

Re: Ooops... i've blown a fuse

Posted: Tue Nov 23, 2010 9:15 pm
by bmcecosse
Not in my 1098 (1965) there isn't! At least - I've never found it - or blown it.
I do see it in the later wiring diagrams - item # 32.

Re: Ooops... i've blown a fuse

Posted: Tue Nov 23, 2010 9:31 pm
by mike.perry
Introduced Sept '66, chassis no.1159663 (Original Morris Minor)

Re: Ooops... i've blown a fuse

Posted: Tue Nov 23, 2010 9:40 pm
by bmcecosse
Ah well - thank goodness I don't have that complication!

Re: Ooops... i've blown a fuse

Posted: Wed Nov 24, 2010 8:46 pm
by catswhisker
To save blowing Lucas 35 amp fuses while fault finding, I use 13 amp mains plug top fuses,
a bit shorter but will fit the fuseholders ok.