Topic: Coil and cap test results

[MauiK3]

If it’s zero or near zero resistance the current draw would grain the battery . Hard to see how it’s zero and still working. Maybe the DVM isn’t reading it right.

[jakec]

I tested the coils for voltage and they were showing "battery potential" voltage. But resistance 0.00

And I know I'm getting a reading, because it changes from blank screen to 0.00. So you think the coils need replacing? I don't know what I could change about how I'm taking the reading to get a better result. I'm using the 20k ohm setting and clipping onto the correct wires.

[david 750f]

Turn the meter to the most sensitive range, your never going to read 5 ohms on the 20K setting..The reason it worked on your plug caps is that the resistance is 5000 ohms or 5K on the caps.

[Scootch]

When you are trying to read the coil resistance you should disconnect the coil leads from the rest of the circuit. Make sure you switch the meter to read resistance. Then when you decide to read voltage make sure you switch the meter off of the resistance function to the volts DC function.

[TwoTired]

Are you trying to read the primary resistance or the secondary resistance?

If dual output coils, measure from HT connection to HT connection without plug caps.  A 20 K range setting should show something around 15K.

If you are measuring the primary it should be 5 ohms or less.  Why would you even think a 20,000 ohm scale would be appropriate?  That's kinda like trying to count the ants in the yard from space.

Maybe you should invest in an auto ranging meter?

Always check your meter by touching the probe tips together to confirm it is working, before trusting any reading it gives you.  First test your meter, then test your unknown circuit.  Imagine if it lies to you.  What have you learned about your circuit or component your "testing"?

These days, I have about 15 meters with which to verify they are working against each other.

[jakec]

To test my meter, when I touch it together what should the resistance be?

[bryanj]

Zero on lowest ohm setting

[TwoTired]

At the lowest setting on the resistance scale would ideally be zero ohms when probe tips are touched together.  But, if sensitive enough, it will read the resistance of the meter leads and internal resistance of the meters circuitry to the actual measuring device point.  This reading should always be subtracted from any resistance measurements you make. 

Further, instruments have an error percentage rating, usually printed in the owner manual.

Just because it is digital doesn’t make it 100% accurate.  All of human creations have imperfections.

[Scootch]

I'm working on another bike which is a Cl350. It has stock coils. I'm trying to test coil resistance but I get a reading of 0.00 on both coils. That's testing across B/W and yellow or blue colored wires.

I also tested the coils on a parts bike that I have which also has stock coils. The result was also 0.00. Just wondering what this means?

Could you post pics showing how and where you have the meter leads connected and the meter setup and configuration.

[jakec]

you were correct and my problem was that the setting was at 20k. Once I set it to the minimum which is 200, I can get a good reading.

My results are 0.2 when testing the meter against itself. And then about 4.2 - 4.3 on coils. So that should mean they are measuring 4.0 ohm. I also have 2 parts bikes sitting here and tested their coils which also gave the same reading. They are all 1970 350's and seem to have the original coils. So, is 4.0 ohm bad? I would think so?

I also tested all 6 caps between the 3 bikes and the lowest I could find was measuring over 8k ohm. So I have gone ahead and ordered some caps.

[bryanj]

4 ohm is fine, should be 5 but that is well within tolerance. 3 is bad as too much load on electrics.
Caps should be either 5Kohm or 10Kohm