Hi Greg,
In order to track this down there are three approaches I have used
with some success. In order of cost and time.
1) Replace fuse with a circuit breaker then jiggle wires until the
circuit breaker pops then try to determine which circuit it was.
2) If you can get it to stay shorted remove the fuse and connect an
ohmmeter from the output side of the fuse connector and look for close
to zero ohms resistance then unplug and reconnect circuits one at a time
until the reading jumps ups you have probably found the circuit with the
short remember to account for the circuits with light bulbs which will
alwasy show some continuity.
3) get some spare bullet connectors and wire up a few inline fuses to
them and plug these into all the circuits then drive along and see which
one blows and that is the circuit with the problem.
>From experience the most likely culprits are.
1) Instrument panel lights if one os the lights pops out of its socket
and touches a metal part under the dash it wil short intermittently.
2) If you have the type of heater control that you rotate to turn on the
fan it sometimes twists around in the dash and shorts out the wires.
3) Loose wires dangling around under the dash and shorting
intermittently.
4) Bare wires in the trunk where something has pinched or cut the
insulation.
5) Anywhere wires pass through a hole in the firewall or fenders etc.
and the rubber grommets are missing and a bare spot has been worn into
the insulation.
Regards,
Peter S.
>Date: Mon, 16 Nov 1998 12:27:37 +0800
>To: spridgets@Autox.Team.Net
>From: Greg Mahney <mahney@central.murdoch.edu.au>
>Subject: Fault finding electrical Problems - AHHH! ?
>Reply-To: Greg Mahney <mahney@central.murdoch.edu.au>
>
>I'm looking for people with logical minds and a basic knowledge of
>electrical circuits to suggest how I should tackle the following
problem.
>
>I have a 1963 MK2A Sprite. The type with just two, 35 Amp fuses. One
does
>the headlights, the other, everything else.
>
>I was driving to my club's big display day yesterday when I noticed the
>fuel guage reading empty and the indicators not working.
>
>Pulled over in dangerous position, engine still running, pulled out the
>blown fuse, replaced it with the spare which immediately blew. Not
>satisfied with that I replaced that one with the other spare - instant
>meltdown of the fuse.
>
>Got in the car and went where I was going using caution and hand
signals.
>
>After the display I wiggled a few wires under the dash and those
connected
>to the fuse box, placed the headlight fuse in the other slot, started
up
>and everything worked.
>
>Bewdy!
>
>Got half way home and that one blew.
>
>BTW this fuse has blown twice before, each incident months apart.
>
>In summary, I seem to have an intermittent short - right?
>
>I imagine I have to go around to every circuit and look for signs of
>burning, touching wires, corroded contacts - and then not really know
if I
>got it or not.
>
>Is there a more elegant solution to my problem? Am I barking up the
right
>tree?
>
>Any suggestions most welcome.
>
>Greg
>
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