Re: Earth resistance


"Duncan Wood" <newsto@xxxxxxxxxxxx> wrote in message news:op.t5hl6sr1yuobwl@xxxxxxx
On Fri, 25 Jan 2008 13:10:29 -0000, Doki <mrdoki@xxxxxxxxx> wrote:


"Doki" <mrdoki@xxxxxxxxx> wrote in message news:5vu50cF1njaj9U1@xxxxxxxxxxxxxxxxxxxxx

"Dave Plowman (News)" <dave@xxxxxxxxxxxxxxx> wrote in message news:4f664e3564dave@xxxxxxxxxxxxxxxxxx
In article <5vrtndF1nuj0jU1@xxxxxxxxxxxxxxxxxx>,
Doki <mrdoki@xxxxxxxxx> wrote:
I'm trying to track down a fault with my car's clocks. One earth is
showing very low resistance (negative for some reason on my cheapy
multimeter), and the other is showing around 50 ohms. Does this sound
anything like right?

If the meter zeros ok on the ohms scale sounds like there's some volts
there.

50 ohms is far too high - I doubt it ever was a true earth connection.
What colours on the wire?

Grey.

By the way, the clocks started playing up after a battery charger was connected up in reverse. Several sets of clocks have exhibited the same faults, so I reckon it's the wiring. Am I right in thinking that the diode between pins 3 and 13 would have allowed basically an open circuit so it's likely the wiring's knackered somewhere? Or should it have munched a fuse?

If you're sinking a reasonable amount of current all the time you might have blown a diode short circuit, which would bugger up your resistance readings.

I'm testing the wiring with no clocks attached. The diode tests out ok on my meter.

.

Relevant Pages

  • Re: Earth resistance
    ... showing very low resistance (negative for some reason on my cheapy ... and the other is showing around 50 ohms. ... 50 ohms is far too high - I doubt it ever was a true earth connection. ...
    (uk.rec.cars.maintenance)
  • Re: Earth resistance
    ... showing very low resistance (negative for some reason on my cheapy ... If the meter zeros ok on the ohms scale sounds like there's some volts ... Am I right in thinking that the diode between pins 3 and 13 would have allowed basically an open circuit so it's likely the wiring's knackered somewhere? ...
    (uk.rec.cars.maintenance)
  • Re: Earth resistance
    ... showing very low resistance (negative for some reason on my cheapy ... and the other is showing around 50 ohms. ... Does this sound ...
    (uk.rec.cars.maintenance)
  • Earth resistance
    ... One earth is showing very low resistance (negative for some reason on my cheapy multimeter), and the other is showing around 50 ohms. ...
    (uk.rec.cars.maintenance)
  • Re: OT: The Olympic Games
    ... access) is only showing the showjumping finals... ... Dressage was online. ... You can't reason with someone whose first line of argument is ... Erilar's Cave Annex: http://www.chibardun.net/~erilarlo  ...
    (rec.arts.mystery)