Better Beaters - Building Cars and Daily Drivers

 Still working on getting those carbs on. 

No, this isn't the nest booster shot.
Now for a little electrical work.

The carbs are bolted on to the manifold, but as I wrote last time I found that there was no spark in the ignition. The engine spun over, but that was it. The electricity obviously isn't getting where it should. 

The coil was very easy to access.
Much easier than the distributor.

I had to check and see if all of the connections were conducting electricity. Every bullet connector, spade connector, or screw connection has the potential to stop the flow. They could be loose, dirty or corroded. The connectors may look as though they are connected but a build up of corrosion can result in a loss of conductivity. In other words the electricity cannot flow through the connection. Electrical flow is often compared to water flow through pipes. 

Troubleshooting requires a logical, methodical, process. So what do I know at this point? 

I knew that the key switch and starter button was energizing the starter causing the motor to turn over. 

That meant the battery had  sufficient charge, the key switch and the starter button were working, and that the battery cables were in good shape. 

So that also meant that the starer solenoid as well as the starter itself were working okay.

However the engine did not cough, pop, or spit back through the carb. I surmised that there was no fire so I held a plug lead near the can cover while I cranked the engine, That confirmed that there was no spark, 

The wires to the coil were intact but dirty so I tried cleaning those connectors first.

The distributor is down there in the dark.
Look under the hose clamp.

I thought that I could gain more space by removing the hose.
There was a surprise waiting for me.

I removed the distributor cap to check if the points were dirty or stuck.

A basic points ignition system is quite simple.

The ignition switch provides power to the + (positive) side of the coil. 

The -- (negative) side of the coil is grounded through the ignition points. When the points are closed, the energy builds in the coil. When they open, the energy breaks, resulting in a high voltage surge from the coil to the distributor. The rotor directs the charge to the appropriate cylinder to light the compressed fuel/air mixture. 

This process, which seems rather lengthy, is repeated several times for every engine revolution, ??? thousands of revolutions per minute. It is hard for me to comprehend how quickly the ignition cycle is completed and how often it is repeated! 

However all that I have to do is to verify that the points are clean and not corroded, that they do open and close, and that the wiring to the coil is intact. 

What kind of fancy diagnostic equipment would I need for this job?

I've also got one of those little test lights
hiding behind the blue tester.

First is a battery powered continuity tester. This is used on non powered systems. When the circuit is complete, the lamp lights. It lets me know that the wiring is intact, the connections are secure, and electricity can travel through the wires. The tester is powered with two AA batteries, three volts. If I use it on a 12 volt car electrical system that is powered, the lamp will burn out immediately. So I make sure to disconnect the battery first. 

This little tester has quite a history in my ownership. My Dad gave it to me when I moved out and away to the L.A. area for my new job in 1982. I think that he had owned it for quite a few years before this. I've had to fix the battery contacts when the wire fatigued from age, but I would never think of tossing it for a new one. When my Dad gave it to me he told me that it would be handy to figure out problems with wiring, and that I should take it with me. I took it of course. While I've been a Dad now of many years myself, even then I knew that it was his way of saying goodbye, wishing me luck, and maybe even that he would miss me. This was my first big move, and the beginning of the bigger changes  that were to follow. I've kind of kept this tradition alive by giving my kids various tools that I brought with me so they could set things up, or could use to fix stuff around their new places. I've had to replace screwdrivers, hammers, adjustable and box wrenches, brooms and even gloves that I've given away.  I hope they will hold onto them over the years, they were given to them as more than tools, they were given with my best wishes, like my advice to check the oil in the car! 

I've got this Innova unit, but this image is from their internet ad.
In other words, not my hand!

My multimeter has a similar function that sounds a buzzer when the circuit is completed. 

The little bulb socket with the yellow wire combined with some
alligator clip on test leads forms my basic equipment.

The second diagnostic tool is the humble test light. I can check live 12 volt circuits. It lets me know that electricity is present by lighting up the lamp! High tech? No, but it tells me what I need to know and what I couldn't determine any other way.

My multi meter can do the same thing, plus tell me exactly how many volts are present at the circuit junction. It can also do more by measuring the resistance in the circuit. That's more than I need right now, though I've finally leaned how to use that function.  

I checked the coil with my continuity tester, connected across the + and -- terminals, the circuit was completed and the lamp lit and confirmed this.  This is not an indication of the strength of the coil, or if it might break down when heated up under load, but it confirmed that it should work well enough to start the engine. 

The -- terminal was loose and the connector wiggled. It appears that the screw thread is damaged and the prior owner had used a wrong screw. I tried to find a better fitting screw but ended up reusing what was there. I cleaned everything reattached the terminal adaptor and superglued the fittings. It tightened everything up! 

My examination of the points, after cleaning, confirmed that they were opening, and they were grounding properly. The wire from the dist to the -- post of the coil was intact and okay after cleaning the spade connector, the wire itself tested good. 

Since the negative side of the ignition checked out, there should be electricity to the positive terminal via the ignition switch. I checked this with the test light, and there wasn't any juice. No electricity, no spark. 

This could indicate a bad switch, a broken wire or connector. However there is an easy work around. I can just run a wire directly from the positive side of the battery to the + terminal of the coil. I don't know if there is an ignition resistor in the system to reduce voltage in the circuit, this is to reduce the chance of the points burning at low rpm. but it shouldn't be a factor in just starting the engine for a very short period. 

So that's as far as I've gotten. I still need to source a battery. I do not like pulling a battery from one of my running cars to use temporarily.  I haven't checked to see if the used battery store is still in business. It's surprising how many businesses have failed, but neglected to take down their websites. I'll just call first instead of wasting a trip like I did for the hobby store. I drove all the way to Sunnyvale only to find a village of empty storefronts. 

I looked at Home Dept and a new battery would run me from 100.00 to 119.00. I've seen batteries for sale at Pick and Pull, I'm assuming they might be used, but I haven't checked. The best course would be to just buy a new battery from my Mustang and use the old battery for the old Jag. Unfortunately there is major drama developing around my Mustang, I'll be reporting on this later. My problems with the Mustang are a big deal that is going to have a major impact on my long range car plans.