Is there any way to test a 6V coil??

[Bob Hoffmann CLC#96]

 I don't have a 6 volt car anymore. Any ideas??
Thanks, Bob

[Bobby B]

Bob,
Hi...Connect one probe to each of the terminals and read the resistance. On a 12V coil, you should read between 3.1 and 3.5 ohms resistance. On a 6V coil, you should read between 1.43 and 1.58 ohms resistance.
Airtex wells supplies this as a guide :
Primary Reistance: 1.0 - 1.4 Ohms  (Connector to Connector)
Secondary Resistance: 5.5k - 9.5k Ohms  (Connector to Tower)
This should give you a basic idea if the coil is lunched or not. Don't forget ballasted and non-ballasted would be different.
                                                                                 Bobby

[walt chomosh #23510]

Bob,
  Truth is, GM had a machine to heat up the coil for testing purposes. A guy can do a resistance check with a quality volt/ohm meter, but the "rubber meets the road" by heating it up. My experience has lead me to installing a questionable unit and driving before calling it serviceable......walt...tulsa,ok

[Steve Passmore]

I agree, All the coils that have failed on me have always done it once they got hot.

[jackworstell]

The hard part about checking a coil is that "will the insulation break down under load/temperature ?"

As others have said...the only way to tell is to install
it and take off down the road and see what happens.
....take a spare with you...

I have replaced a number of coils over the years.....looking back I believe
that most of the time unnecessarliy.   The tough thing about
a coil is there's no way to do a comprehensive  all inclusive bench test

I would bet that most of the time a coil is replaced it is       "   I've fixed/replaced a bunch of things
and I still have the problem....maybe I should replace the coil "
Certainly I have done this a number of times over the years....

Jack Worstell

[bcroe]

Only testing a coil at full plug operating voltage is going to find
failing insulation, even though resistance may check.  And
apparently at full temperature.  Maybe this test is being done
somewhere.  Bruce Roe

[fishnjim]

If you just want to know if it's OK, or to throw out, I don't see any problem with the quick resistance check.  If it's open circuit, either side, or leaking, you'll know it's shot for sure.   
If it passes, then it's 5050 it's good.   A normal 6V coil is not a rare part, so I'd just chuck it.

Whether or not it'll put out full voltage, you have to test in a spark tester.   They used to have these test machines, but like the buggy...   An old grimy auto electric shop with an old guy that smokes cheap cigars would be a good place to start.  Those are getting scarcer as well.   He'd probably test it for free.   That's even rarer today...

[Bob Hoffmann CLC#96]

Guys,
Thanks for all the responses. I have a decent VOM but some of my readings don't match with what was said. I'm testing the NOS 53/54 I have for sale & an NOS 1115128 & a used one.  I'll give a report ASAP.
Bob