[Healeys] Distributor to spark plug lead continuity

[Bob Spidell]

Thanks.  I was taking a SWAG that it was impedance.

On 5/21/2020 10:35 AM, jim wrote:
> symbol  on meter settings indicates "diode test" ..Puts a known 
> voltage across diode and measures "diode turn on voltage" ie where it 
> starts to conduct  ..not the same as ohms ...
>
> Jim
>
> On Thursday, May 21, 2020, 8:29:27 AM PDT, Bob Spidell 
> <bspidell at comcast.net> wrote:
>
>
> First, why on earth did you have a spark plug lead on a radiator 
> cap??? (presume you meant 'distributor' cap?)
>
> It looks like you have your multimeter set to diode test (maybe that's 
> how continuity works on your MM?).  The reading is probably ohms, 
> indicating a very low resistance circuit, but to be sure turn the MM 
> control knob one click clockwise, to the 200 ohm range ('200 omega').  
> It'll probably give the same reading; i.e. .792 ohms, which is about 
> what you'd expect from a short stranded copper wire lead (IIRC, one 
> ohm per foot of cable is considered normal, even copper has some 
> resistance).
>
> Bob
>
>
> On 5/21/2020 7:55 AM, Linwood Rose via Healeys wrote:
> Hi guys,
> Educate me. When doing some preventative maintenance, I pulled a spark 
> plug lead out of the radiator cap (using a 123 distributor) the cable 
> pulled away from the terminal - not a particularly unusual outcome. 
> Got a new 90 degree terminal and crimped it on to the cable (Pertronix 
> cable) and before I put the boot on the end of the cable I thought I 
> would check the continuity. It barely dropped below 1.
>
> So then I checked a brand new, never used, cable made-up by AH Spares. 
> As shown in the image below when the sensors are attached to each end 
> of the cable I get a reading of .792 which is not sufficient to even 
> sound the beeper on the multimeter device. I suppose there are degrees 
> of continuity (not just on/off) but I guess I expected the alarm to 
> sound and the reading to drop to near zero.
>
> Could someone interpret these findings for me?
>
> Thanks, as always.
>
> Lin

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