SIII Won't Fire Up

Greetings, Listers!

My beloved Big Red won’t start.

Turns over fine, gets plenty of fuel, won’t fire up. Behaves as though the coil is disconnected.
Checked/swapped cables, looked for loose connections around the coil, ballast resistor, and Crane EI (no Opus!).
Have not done any low voltage checks yet at the coil.

Crane Fireball ignition is 15 years old
Coil is less than 5 years old
Ballast resistor and voltage regulator are original
No previous issues, has been running great, wasn’t working on anything, just failed out of the blue yesterday morning
Gets driven weekly.

Some Questions-
Could the ignition switch activate the starter but not the EI (i.e. faulty switch)?
Measure voltages at coil before and during starter turnover?
Best way to check coil and ballast resistor?
Any other possible components I’m not thing of?

Thanks, All

Mike King
(I’ve got to get this baby ready for the next Big Leak!)

Hi Mike,
Yes, you must get Big Red going again before the next OL. That’s a V12, right? :slight_smile: I’m not familiar with their components, but sounds electrical. Are you able to check for spark? @L.Lynn has experience.

Best of luck. Hopefully it’s something straightforward.


Thanks, Drew! Yup, no spark.
Just like the coil cable was unplugged

Michael King

EAR Professional Audio Video
2641 East McDowell Rd, Phoenix, Az. 85008
800.473.6914 602.267.0600 fax: 602.275.3277

Hi Mike,

Good thing we have a couple of months till the 'ol :wink:
Sounds like you’ve got a pretty good grip on the situation and the sudden nature of the failure to progress suggests ignition. I think your going to have to see if you have power with the key on as the switch could do this, then it’s going to be (most likely) either your 15 yo Crane or the coil (seems like the coil would be more gradual with loss of higher RPM with missing but still possible of course). My feeling is that the ballast is pretty near bullet proof so it would be last on my list. You could try just switching out the coil as that’s relatively easy and cheap but check the gin switch first.
bet you have “Big Red” up and running in nothing flat!

Couple of other thoughts, check the rotor, they do fail occasionally and look at the cap. You might see if you have spark from the coil first though.

Thanks, Lynn! Duh, the rotor. I’ve had plenty fail on my MGB and also the Jag. Why didn’t I think of that? :thinking:
Nothing wrong with buying a spare rotor and coil in case that’s not it. I’ll start there.

Michael King

EAR Professional Audio Video
2641 East McDowell Rd, Phoenix, Az. 85008
800.473.6914 602.267.0600 fax: 602.275.3277

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Had a similar issue several years ago with my series III. I was stumped! Somone here suggested the actual cause, the ballast resister. c.37759. Maybe something to consider if testing does not reveal any other faults. Good luck!

My experience with ballast resistors is that the engine will fire but immediately die when the ballast comes on stream to drop the voltage.


Reading your post have you solved your starting issue? My first S3 E-type, a’71 2+2 was an experience. Boy what a learning experience that car was ! ! ! Not too long after purchasing it problems began. Driving along, suddenly the Tac died along with the engine. Attempts to restart went no where. After investigating “no spark” I found the rotor was shorting to the distributor shaft. Early Lucas rotors were prone to this, stranding owners at the most inconvenient place or time. That happened three times within a six month period. Also, one episode even cracked the distributor cap. Therefore, I carried several extra rotors and a new distributor cap — just in case. Also went thru several OPUS amplifiers too. That’s when I switch to the Crane X700 ignition. Never had a problem with that system.
So, if you haven’t replaced the rotor I suggest doing so. Also, take a good look at the dizzy cap insides. If you still don’t have a spark from the coil the I would suspect the Crane amp or optical trigger.

Happy Motoring,


'74 OTS
'99 XJR
1947 Stinson 108-1 “Voyager”

Rotor it was!
Occam’s razor wins out once again.
Thanks, Lynn, thanks all.
The rotor should have been the first thing that came to my mind.
I’ll get another and add to my very lean spares kit.
Time for a nice drive in beautiful AZ. weather!


Greetings All-
I’ve been chasing all the electrical Gremlins since May, replacing rotor, cap, swapping out Crane unit, new plugs, etc.
I have gotten it to run well for a while, then…it cuts out fast, but will fire up a minute later. This is definately not a fuel issue, been there, done that. Now I find my voltage at the coil from the ignition switch is 6.5 volts. Something is amiss! Faulty switch? Ground issue somewhere? Your advice is welcomed!

Mike, a good way to start is to put a wire from the + side of the battery to the + of the coil. that way you are bypassing all the stuff at the front end. see if that works, then let us know. I once had an “intermittent” at the coil end of that, took a while to find.


“Prediction is very difficult, especially if it’s about the future.”

Physicist Niels Bohr

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Morning Mike,
Sorry to hear your still having problems with ‘Big Red’, I would look at the ballast resistor and then the ignition switch. Be sure and check grounds/connections for everything.
I’m sure folks who are smarter than I will be adding their thoughts.
Kindest regards,

Thanks, Lynn. I have checked the BR resistance, no dead shorts or “opens”, would love to replace but none available for quite a while now.
I’ve been checking grounds and connections up the ying yang but no luck. Maybe I’ll just run 12v to the coil from the battery when I get home and try to blow something up!

That’s what I would do too, IIRC, and this is a big ‘if’ there is a resistor wire to the coil. I was working on a friends car some time back (years) I decided to clean up the wiring to the coil and removed this wire and the car would not start, it took awhile to figure it out but I saved the old wire and varoom, it started. The other thing I vaguely recall was that the ballast resistor was designed to lower the voltage to the coil when the car was running, however the ballast resistor was bypassed when starting the car so the coil would see the full 12 volts. Help me out here folks because I could be all wet on this and electrical stuff is not one of my strengths along with my math skills. So if the coil is only showing 6V when starting I wonder?

Correct, the ballast reduces the volts to the coil during the ‘run’ time and is bypassed for the start, supplying 12v to the 6 volt coil at least thats what I understand, I’ll Need to go out to the garage to check what the coil is on my ‘66 ‘S’ that I fitted up with a ballast resistor many, many, many years ago.

Thanks for all the suggestions, Listers and friends.
Here’s the strange results from jumping directly from the battery to the coil last night.

  1. With jumper, car starts right up then dies suddenly in about 10 seconds (hot or cold), jumper still attached. Car does not start without the jumper.
  2. If I start it up again with the jumper, then quickly remove it within the 10 second time frame, car continues to run for 5 minutes just fine, then dies.
    Crazy, huh?
    My latest guesses are ballast resistor or EI guts in the distributor.
    I love a good mystery but this is taking too long to solve!

Now, THAT sounds like two different issues. The ten minute thing is a symptom of a coil heating up then going out. I believe the coil would be hot at that point if it was the issue.

Also… ten minutes of running almost clears it of a fuel or vacuum issue, nicht var? (ain’t that so?, in German).

And finally, the hot wire to the coil “essentially” clears the wires from battery to ignition to coil …unless there is a third issue there.


“Prediction is very difficult, especially if it’s about the future.”

Physicist Niels Bohr

Thanks, LLoyd.

I kind of agree, BUT

Coil is new, doesn’t get hot, but the BR sure does (always has). Spare coil behaves the same way.

Yes, just can’t be a vac issue sitting there running fine for 10 minutes. Most of my vac ports are closed up anyway.

And, as you know, I’ve had fuel issues before but that’s a much slower shut down as the bowls get drained.

Also, there is the distinctive smell of unburned fuel after it shuts down.

This one is a real challenge. I haven’t had anyone work on my engine for years but I see a possible flatbed trip in my future!

Michael King
EAR Professional Audio Video
2641 East McDowell Rd, Phoenix, Az. 85008
800.473.6914 602.267.0600 fax: 602.275.3277

I’ll be the first guy to admit to near-total ignorance of automotive electronics (and since it ran for 10 minutes this comment may not be valid at all) but what about weak or missing ground?
Would that result in the symptoms you’re experiencing?
Since you have jumped the battery <–>coil, jumping the engine to a good, known ground would be too easy (but ultimately fruitless – see opening statement).