73 240 No spark

[240dkw]

Yes that is correct you want power all the time, now move on to the other measurements and stop cranking it over looking for a spark. I got you to install the jumper so we can test further down the circuit to see why you’re not getting a spark, not to fix the problem. If you want to understand how the circuits are working look again at the information I posted in post #33 on how the ballast works. 

[Shawninvancouver]

I think when the jumper is on and the car in run position there is 12v all over  both sides of ballast and with jumper to coil both + and ~ on coil have power 12v  when power goes to the pos side of the coil it also goes to neg side   Is that right? 

 

[240dkw]

Kind of, there is always power on both sides of the ballast and the jumper is just there to bring power to the coil. And yes power goes through the coil to the points.

[Shawninvancouver]

Ok 240. Can I ask you this.  Is there a way to measure if there is voltage coming out of the coil lead when I try start position on key? Can I put multi meter probe inside middle of coil and measure that ? To see if power is coming out of middle. ?? So power is supposed to be on pos and neg of coil ? I have always had that.  Now what makes the coil shoot power out of the middle? Is that the points or something on the distributor?   

[240dkw]

No that is high voltage coming out of the centre post on the coil, that is why you test it using the coil or plug wire to ground. The high voltage is created by the points going open from a closed position. Again you need to read and study the info I posted in post #33. It is all there on how it works And why I want you to measure the voltage at the dizzy terminal and at the points (with the points open) to make sure everything is working correctly.

Yes power on both sides of the coil is good.

[Shawninvancouver]

Ok.  So I should measure voltage on dizzy at both sides of the points with points open or closed and car in run power. Not while trying to start ??what should it measure ??

[Yarb]

Just measure it and report back please. Post 125 in parentheses says “Open”

Edited May 7 by Yarb
Add

[Shawninvancouver]

So hook multi meter to ground and have key on then measure on both sides of points ?

[Yarb]

Post 33

[Yarb]

[Shawninvancouver]

Hey yarn. I red circled wires that work fine and gave 12v on start/run. The yellow circle gets no power. Not sure what it supposed to do power wise.  It goes in tach and comes out.  Does it get power at any point?

[Shawninvancouver]

Another question I have that has been bothering me is that I’m not sure if the spark plug wires are on proper order when we found top dead centre by putting a screwdriver in the spark plug hole and number one on the piston is at the top is the distributor rotor points to a random spot maybe like 3 o’clock while looking at it from the driver seat we assumed that would be number one, which is where the rotor points when the engine is the top dead centre is that correct? Is it always a random spot? It is not anywhere near where it should be on the distributor cap mark. What will happen if we have our spark plugs out of order will it start and just misfire or no spark at all?