1972 500. Testing ignition components

[BlazinC5]

So, I finally got around to messing with my grandpa's old 72' 500. Been sitting for over 20 years. Currently I have things mostly cleaned up and decided to look at the ignition components. As that's what stopped the sled from running. It lost all spark and nobody came back to mess with it after it was parked after that. I found some information on testing a few things. It seems my points are in good order. However,, I'm unsure of the coils on the stator plate and the condensers. I've tested them with a digital ohm meter but have mixed results. The #'s seem close to what I should see but move around on the display screen a bit.. And am unsure if im doing it properly.
The ignition coils for the spark plug wires I'm sure are junk. As they both have a small amount of resistance from the white/red lead to frame of the coil,, but have nothing from lead to spark plug wire port. Infiniti resistance and no continuity... That makes me wonder if something went bad in the stator area and took out both the coils.. I tried looking for some replacment condensers too since they would be cheap, but no luck on a conversion part # either for that particular sled. Any idea's?
BTW, I do have the stator plate assembly off the engine.

[400brian]

When I get a bit of time, I'll go through this with you and see if we can diagnose this. stand by...

[400brian]

Often, all that is wrong is that the points are corroded. Let's start there. Connect your ohm meter to the breaker plate (ground ) and the red and white wires one at a time. The points are closed and should register no significant resistance. Open each point with you finger, and resistance should significantly increase. The generating coils are a poor ground, but there is leakage. I normally use a test light for this, as you use the same to set the timing. Clean the points with 400 grit black oxide paper and blow the residue out.

[400brian]

As I said, I use a test light for much of my ignition work. It is just a cheap 2 D-cell plastic flashlight that I have wired in a pair of wire leads with alligator clips on the ends. This is used in timing the engine as when the points are closed the light is as bright as when the clips are attached to each other, and when the points open, the intensity drops by around half.

I assume that if a condenser was grounded, the light wouldn't dim, and if the condenser was open the points would be fried. If the ignition generating coil was grounded, I would think the light would stay bright, and if it was open, I would think the light would go out. Both of those are describing 100% failures, and it seems like life is rarely that simple.

The goal here is to get at least one side working, then you can use that to pin point the problem with the other side.

Let us know what you find.

[big jeff]

400Brian I have 2 questions for you where did you buy the dial indicator that fits in the spark plug hole and how did you wire the flash light thanks Jeff

[400brian]

Here is what I have https://www.ebay.com/sch/i.html?_nkw=ht ... eName=GSTL

I bought my set on ebay a number of years ago. It was supposedly used, and coming from a school. I could not tell it from new, and I think I got it for around $60, a huge discount over new.

Here is something a bit cheaper http://www.tooldiscounter.com/ItemDispl ... AkQAvD_BwE

All I use is the dial indicator, a 1" extension on it, and the 14 mm spark plug adapter.

The light is really simple. Take a cheap old fashioned flashlight with an incandescent bulb, and drill 2 holes in the but end. You need 2 pieces of automotive wire, 16 ga. or thereabouts, and foot and half long or whatever you want. You put alligator clips on one end of each wire, and strip off about 3/4" of insulation off the other end. One of the wires is then fed through a hole in the butt, and the bare wire is tightly wrapped around the spring in the butt end. If you want to get fancy I guess you can solder it on as long as you don't take the tension out of the spring with the heat. You then feed the other wire in through the other hole you drilled. You splay the strands of the wire out to a fan shape, and duct tape it to the base of a battery. You are attaching the wire to the battery, AND, insulating it from the spring. You put the flashlight together, and it should now work normally if you connect the alligator clips to each other, and not at all if they are not.

[big jeff]

400brian Thanks for the info this will help in timing on my older sleds again thanks so much Jeff