which coil do I have?

1) click to the right in red,,, Motor Magazine

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3) eye on electronics

• DMM

till they come up with sum'n better,,, till then 12v till the day I die,,, and i know the difference,,, taint hide'n nuttin,,, not a Me to man

What most folks don't figger on is you need to check amps to the coil at charging voltage,,, not static battery voltage.

The only way I know to do that with out a low amp probe and a lab scope is install a battery charger,,,14.5Vs are so,,, switch on,,, points closed,,, DVOM in series to the coil,,, use amp set'n

I don't own a cheap DVOM,,, don't the cheap'ns have a amp set'n,,, any one interested in a damm good mega buck meter at a low price keep yer eye on craigslist for a Snap-on Vantage power graphing meter,,, I have seen one for $75,,, seen a few for $200,,, folks are dump'n them for the nicer vantage pro,,, The Vantage sells for around $1500. i have had a lab scope for years but always wanted a Vantage,,, picked up one at a deal,,, shore nuff I was miss'n out,,, nice little toy in the rite hands.

soundguy

You can do an in-circuit test.. and close your points, and put an ammeter inline, use your amp reading along with system voltage to calculate your correct resistance.. once you hav ethe correct resistance number.. you can determine if it was intended to be a 6v or 12v coil, and then add serieal resistance as needed. The calculation step could be skipped by adding serial resistance till your amp reading was between 3-4 amps.. etc.

soundguy

With the flakey parts and meters, getting a right number may not be as important as by gosh N' by golly.

It would help also when the points get out, just reduce the resistance one click an if it runs better you have one point of info for diagnostics....

russb, long on ideas, short on follow through.

Easy to build... but really pointless ( no pun intended ).. just getting the correct ressitance in the line and keeping the contacts clean are all that is needed.

the range of acceptable resistances is small enough that a simple 'test and plug' diagnostic approach can work.

But if you do build one.. I'd like to see pics / schematics all the same...

soundguy

Sound Guy, I sort of garbled what I was trying not to say. Not sure if this scan will work Link

Maybe better to go with higher resistance resistors in parallel. I don't want this to backfire on me where I would have to defend myself by actually building something.

I'll have more ideas.

Spokane is getting heavy snow, so I have logged some seat time.

Kind regards, russ

• ONE source

The switch box you drew out is functionally ok.. but it is bulky, needing lots of switches. What you are trying to do can be accomplished with a multi-position rotary switch ( SPMT - I guess? )the switch will have 2 wires to it and a bunch of switch contacts to wire up.. run all the resistors in series, have the switch 1st wire start after the first resistor, and have the switch 2nd wire run out to your load. Now.. wire each of those resistors to the rotary contacts.. so that as you turn the switch you are adding 1 more resistor in line.

As Dell said.. it's a long way past your elbow to accomplish what you need.. unless you just want to build that big stepped variable resistor. ( Wow.. dell brough back some nostalgia for me.. I haven't used a decade box or the term itself in 20 years! )

As Dell points out.. due to ohms law.. V will be correct , and in relationship to A(I) and R.. so if you are getting correct voltage at the coil, you can assume the load (R) is correct, and thus A (I ) will be correct.

Soundguy

Soundguy

Like about a dozen or so folks will say, it is difficult to get reliable ohm readings with a ohmmeter. If it is a multimeter capable of reading amperes, connect meter and coil in series with a battery and read current. Divide the battery voltage by current to obtain ohms. Would be even better if you can simultaneously read coil voltage and coil current to eliminate voltage drops in battery, wires, ammeter, connections, etc.

Dukester