smoking ballast resistor?

michael mayben said:
ya really need to use a dvom (digital volt/ohmmeter) to check resistance values that low with any accuracy!

Ron's procedure is correct!
Click to expand...

Soooo, im trying to do the voltmeter thing. When I place the voltmeter into any of the ohm checks (2000k down to just 20) it reads a 1 on the meter. Touch the leads together, and it will either zero out for anything with a k after it, or just go blank with a non k value. When I put the leads to the coil and/or the resistor, the screen counts down to zero.

What am I missing?
 
Can you post a pic of the instrument that you are using???

But it sounds like yours is not the "auto-ranging" type.

So set the resistance scale using the selector knob to "20". Most likely that is a "20 ohm scale". That will read from zero resistance (0.000) depending on how many decimal places the display can show, to 20.000ohms, or "20 ohms". That is the scale you want to use. If the instrument is turned on, the 20 ohm scale is selected, and the two probes are not shorted together, then the display will read normally "ol or "ol" which means "open line" or infinity.

Then put one probe on one terminal of the coil, and the other probe on the other terminal, both probes must make perfect contact! The reading on your meter May flash" or scroll up and down but should finally lock down. The reading will be the actually primary winding resistance in the coil you are testing! The sv coil will read between 1.4 and 1.9 ohms if it's ok. The I-4 coil will read between 2.8 and 3.2 ohms or so if ok. Again a few tenths of an ohm one way or the other is not an issue!

If in fact you have a reading of 0.000ohms, that indicates "shorted turns" of the primary winding, lowering the overall resistance below usable specification. If the resistance is greater than say 3.2ohms, then the current draw/saturation will not be suitable for that distributor! If the reading is "ol", that indicates an open primary winding and the means the coil is not useable!

We must see a pic of the instrument you are using to fully understand what tool you are using and to help in explaining how to use it! They are not "all the same"!
 
voltmeter.jpg
 
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Good pic!

Wrong scale selected in that shot however!

Put the knob on the "200" scale. Then it can read any resistance under 200 ohms to what appears to be 3 decimal places! That is your "lowest" scale!

In your pic, the knob is on the "20k" scale waaay to great a range for a coil check!

And...the pic shows that instrument can read up to 10 amps dc for a short period of time. To do so, put the red test lead in that top jack marked "10a". Put the selector knob in the "10a" position above and to the left of that 10a jack. Then connect the black test lead to the coil negative terminal, and the red test lead to the distributor pigtail ya remove from that same terminal. That is called putting the meter in "series" and is how ya measure current (amperes). Start the engine, the resulting reading will be the current flow through the ignition primary circuit, just like ya saw in my picture. In my case, the instrument I use has an "inductive" pickup for reading both ac and dc current...ya don't insert the instrument in series in the circuit like ya do on yours, an inductive pickup clamps around the conductor carrying the current!

Again...this shows ya just two of the many types of instruments, resolutions, and styles that all of us use every day...if we don't know exactly what instrument is available, we're only guessing!

Great pic man!
 
Thanks for the info, yet again.

So I ordered a pertronix flame thrower coil. It was 2 bucks more than the e502, and took the same amount of time to get here. I couldnt find a cheaper 3 ohm coil.

Also, as info, the neihoff cross for the wells al752 you mentioned is l125dcs. I liked the duralast better, as it came with tab mounting bolts, where the neihoff comes with nothing but a mounting screw (not a bolt)
 
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