checking ohms on the coil

G

gosnell

New Member
Ok Im not sure what Im getting so I hope you can clarify. Using the old fashioned analogue multi meter after Zeroing the meter putting the meter accross the +& - terminals no matter where I set the from 1to1k the needle finnishes at Zero on the ohms scale, when I put the meter accross from the plus terminal to the HT outlet (sec ondary) it reads 11 so at 1k I read that as 11,000ohms. its the reading accross the +&- I dont understand, just for extra info the coil is a new new unit and is NOT on the car I was expecting about 1.5ohms ?


John
 
Hello John,

So you have set the meter to read ohms and then touched to leads together to zero it. To read the primary resistance you place the red (pos) lead on the +ve terminal, and the black (neg) lead on the -ve terminal. If the coil is a points coil, then the primary resistance will be in the order of 1.2 to 1.5 ohms.

What is the smallest resistance range that you can set on your meter?

Ron.
 
Hi Ron , it goes up in 10's from 1-10- 100- 200-1K, I tried all position zero the meter every time and it allways goes to the Zero posion on the meter. Yes I was checking across the +/- terminals. What I forgot to say is the coil is part of a electronic ignition package by Newtronics and the information on the coil says for use only with a ballasted system with electronic ignition, NOT points. As I said when checking the secondary side it appears to be 11,000ohms .


John
 
Hello John,

Yes an electronic coil must never be used with points, will burn them out in no time at all. I have not heard of Newtronics,...have you tried to contact them to ask about the specs of the coil?

Have you tried measuring the resistance of a known item, some resistors for example so you know that your meter is not at fault?

The secondary resistance figure sounds acceptable, so unless the primary is less than one ohm... :?

Ron.
 
the coil I use on my pertronix ignition is 0.6 Ohms, I beleive that even higher powered systems may use a coil with an even lower primary resistance.

What is the lowest number and highest number on the Ohms scale of your meter on the X1 range ? it may be that the coil is only points of an Ohm and that your meter is just not up to registering that level of resistance scale wise, if that is the case even moving to a digital meter may make not a lot of difference.

Graeme
 
All the settings on the analogue meter always comes back with a Zero rating so I think that an digital meter is the only way of picking up the reading, I was quite happy with the 11.000ohm reading on the secondary side.


John
 
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