I was driving my '68 Cutlass on Sunday. The car has been running well, and I have just about got all the bugs worked out.

Anyhow, the car simply stopped running. It was like I turned the key off. I coasted into a gravel parking lot, and immediately thought points, condenser, or coil. After my wife picked me up, I picked the parts up at O'Reilly's, and changed the coil out where the car was parked hoping that was the issue. No dice.

I pulled the Cutlass to my brother's shop, and changed out the points and condenser. The points were toast, and the condenser was leaking. That had to be the problem, right?

No dice.

I put a test lamp on the positive side of the coil. When the key is in the "On" position, I get a brief flash. Not when the key is in the "Start" position. I also noticed that the resister wire running from the positive side of the coil back to cabin (fuse box?) is getting hot when I crank it over.

I did check all of the fuses, and they are all in good shape. This problem has not effected any other of the accessories: lights, radio, wipers all still work.

I am thinking that I may have an ignition switch problem. Before I spend another $20, I was wondering what everyone's opinion is.

Should I replace the ignition switch?

Thanks!

 

Stick or Auto? Do you have a good schematic/diagram pack for you car? If not start with that. We can guide you better if you have these items in hand.
First some basics:
With a VOM do you have 12vdc (Correction ~9vdc on points ignition on + side of coil) to the ignition system with the key in the run position?
If not:
Verify the neutral safety switch is not holding the ign sys (Correction holding the starter out). Jump it out of the circuit or at min move the shifter around and verify 12vdc. Not knowing the config here it could be one of 3.
Verify all engine grounds are clean and tight.(positive cables too)
Check the main harness bulk head where it passes through the firewall. Pull it apart and inspect.
Look at the points wire where it enters the bottom of the dist base through the rubber grommet. Check that wire for continuity, open or broken insulation which could be causing it to ground out on the dist body.
Then inspect the ign switch.
Edit....The fact that it dies after a period of running says possible heat load? If you have a spark tester and simulate the condition attach the tester between any plug and wire and crank away.
As everyone's mentioned here verify point gap, dwell etc...Look at the neg wire where it attaches to the point set. Make sure its not contacting or has the potential to contact anything. They will ground out the points and it could be intermittent.

 

should have constant power at pos side of coil, wiggle the ign switch, does the test light flicker ?

 

The neutral safety switch only effects the purple wire on the starter, you should have constant voltage at the coil + with resistance with the key on. When the key is in the start position the solenoid feeds the coil + through another wire (resistance bypass wire) to allow the coil full battery voltage when starting.

When you changed the points did you regap them or set the dwell?

 

Here's a thought: Instead of randomly buying parts and installing them, you MIGHT want to try some free troubleshooting first.

The fact that you don't have constant power on the + side of the coil is your problem. Figure out why. It is much more likely that you have a bad resistor wire than a bad ignition switch (though the latter is a possibility). For starters, run a jumper wire from the + side of the + terminal on the battery and see if the car starts. Note that you will need to remove this wire to turn the car off. If it runs, you've isolated the problem to the resistor wire, firewall connector, under dash wiring, or ignition switch. Trace the wire back from the coil to the switch until you find the problem. THEN, go buy the correct part to fix it.

 

I do not have 12V at the coil with the key in any position.

I have had to put the car in Neutral to start recently. I could see this being an issue if the car won't start, but it died on me 8 miles down the road.

I haven't really looked into the wiring harness yet. The wires that I have been handling seem to be in good shape.

Do you think that the Neutral Safety Switch could be the culprit?

Thanks!

 

Yeah, but I almost have enough on my rewards card to get $5 off my next purchase at O'Reilly's

A friend here at work suggested using a "remote starter switch". I think that I can rig one up.

Thanks!

 

I haven't set the dwell or the gap yet. I was hoping to get the car running first, then tune her up.

 

Search is your friend:

https://classicoldsmobile.com/forums...-ignition.html

As Joe said, you can spend a lot of money and time just randomly changing parts, or you can troubleshoot, and fix what's actually wrong.

- Eric

 

First set your gap to .016. If the gap is way off or the points are not opening it won't start,

Then as Joe said above, run a jumper from the + post on the battery to the + post of the coil. Crank it with the key and see if it starts. As noted above you need to remove the jumper and turn off the key to shut the engine off.

 

Why????

Again from the top.

The STARTING circuit has nothing to do with a problem where the engine cuts out while running. They are completely unrelated. The NSS has nothing to do with your original problem. Also, by simply adjusting the NSS, you can avoid needing a remote starter. You can also simply jumper the purple wires going to the NSS as a temporary fix, which saves needing to crawl under the car to connect a remote starter.

None of this will fix your original problem. Again, if you don't have power to the coil in the RUN position, THAT is the problem. Fix it as described above. Also, get a Chassis Service Manual and look at the wiring diagram to see what components are or are not part of the circuit in question. This is not a particularly complex circuit.

 

Thanks again. I have a lot of good information to troubleshoot with now. I guess my method of replacing parts until something fixes the problem isn't the best approach.

 

Do as Joe says, run a wire from batt pos to coil pos and try. Check point gap. I don't believe you will see volts at coil pos with key in run if points are closed or coil neg wire is grounded.(As a matter of fact I set initial timing on points cars when starting a rebuilt engine with a test light.)
I have also seen people install points and put the wire on wrong and grounding it in the process.
If it cranks, it ain't a neutral switch.

 

Also a points car should not show 12 volts with a meter and the key in run.

 

That's a really good point. The easy fix for this is to put a piece of cardboard between the points temporarily while you check voltage. Also, use a test light (or a high-impedance voltmeter), not a cheap low-impedance voltmeter, as the resistance in the bulb will help find questionable connections. A low-impedance voltmeter won't.

 

A jump wire and test light are my go-to for diagnosing point ignition.
.
If the jump from bat. pos. does start it, you know ignition feed to coil is faulty.

Connect test light between coil neg and ground. Ignition on and cranking engine, light should flash. This means primary ignition is good with no open or short to ground. (points, condenser, wiring and primary coil winding. Problem most likely in secondary ignition.(coil, main coil wire, cap or rotor)
If light stays lit, circuit is open.(points open or corroded,wire broken or dissconected)
If it does not light, there is a short to ground.(points closed, bad condenser or grounded wire, or (unlikely)bad coil primary winding)

There is more to it, I'm not good at explaining. BUT I got real good at doing this working on vehicles out on the road.