No Spark

No clue but that is what I was assuming. He was getting continuity on both sides of the points while they were open. That's about the only way it could be jumping across. I had him disconnect the condenser from the points plate to take a ground via that out of the equation.

(I was diagnosing by phone)

RUNS GREAT

So............let's see, if you have points, you should carry a spare set and a condenser too since you never know what might happen with these hi tech mechanical things

Imagine that

I was going to happily buy an extra but I got the only set within 20mi of Badin Lake. Will have to find another set or two

Mine is running well too. No spare points on hand!

KENO wrote: So............let's see, if you have points, you should carry a spare set and a condenser too since you never know what might happen with these hi tech mechanical things Imagine that

I guess now after the 40 odd years I've been running points in the X55 and the Atom, I need to make a trip to the auto supply!! Thankfully I have that EI conversion thing in the Tique. That will never give out!

I'm kinda curious what your ohm reading was when the points were open Dave.

Was it zero or maybe some higher number like 15 or 20 ohms for example but nowhere near infinity?

phatsat67 wrote: No clue but that is what I was assuming. He was getting continuity on both sides of the points while they were open. That's about the only way it could be jumping across. I had him disconnect the condenser from the points plate to take a ground via that out of the equation. (I was diagnosing by phone)

What Zach said above is what I was wondering about

Yes, first thing to do when checking points is disconnect negative and check for voltage changes while cranking.

The points were bad and conducting on the non grounded side. New points = runny good.

I didn't have him check an Ohm reading with points open. He was just showing voltage on both sides so that's all you really need to know.

Yes you will,

You connect your VOM or test light to a positive and let the points do their job grounding that circuit out. (connect negative end to points wire) You'll see voltage fluctuation on your VOM and you will see your test light flashing as the points open and close while cranking the engine.

Maybe you've never tested points using a positive supply? I have tested numbers and numbers of points systems this way.

KENO wrote: results I learned that from a book called "Pete's pointers on perfecting the performance of your prehistoric but still pretty dependable points system"

Well like I said in another post a little while back "like most things in life, there's usually more than one way to do the job"

phatsat67 wrote: One of us probably needs to post up a nice guide to trouble shooting and keeping a points system working properly,

We'll call that a definite maybe for right now.

I'll PM ya' in a week or so about it.

You're probably looking at the TRB typical mid 80's diagram. It doesn't show a voltage regulator because it's internal to the alternator

You should be looking at this diagram for a closer representation of what you have on your 78 Commander which would be an alternator and a separate voltage regulator




The regulator should maintain the system voltage at roughly 14 volts plus or minus a little whether it's internal or external.

Your original thread shows the external regulator on the back of the engine.

Since you have a Commander no diagram seems to be around for that engine but the old PCM one above is fairly close. The wire colors for the voltage regulator might be different

It sounds like the new points a while back were just a band aid for some other problem.

What do you have for a ballast resistor/resistor wire.

999,999and 1/2 times out of a million a ballast resistor or wire fails and gives an open circuit and no voltage to the coil and therefore no spark. They don't fail in the low resistance direction and act like a solid piece of wire

If your points got fried in a short period of time it sounds like high voltage/current to the coil and points from a bypassed resistor or no resistor

How about a picture of the resistor showing the wiring to and from it

In your last paragraph do you mean "red wire from the voltage regulator" ?

Maybe a hand drawn picture of the wiring and the breaker you installed would be good to show what you're talking about

If it's a 12 gauge or so wire running like the purple wire coming from the regulator in the PCM diagram above, it's telling the regulator what the system voltage is

It could be hooked to the ballast resistor inlet like in the diagram or it could be hooked to the battery side of the solenoid, either place will work