PERTRONIX IGNITION

GINO: Your CAPS LOCK key is stuck ON.

It sounds like a bad Ignition switch. You may be able to tell by watching the OIL/GEN lights. They should remain lit during cranking. If they both go out in the cranking position, the switch is bad.

Speedy Jim

Hi there Gino,

I've been through this recently, here's what I learned...

Like you, I installed a Pertronix unit in a 6V car. My problem was that while the starter was cranking, the voltage would drop below the

5V required to trigger the unit so no spark was generated. Once the key was let off the starter, the car would often (but not always) start right up - i.e. it would only start after, but not during, cranking. So if you have a voltage drop during cranking, you experience this problem.

If you connect a jumper wire from the battery cable at the regulator to the positive terminal on the coil (just a length of wire with an alligator clip on each end), you'll probably find it starts up immediately (but obviously you can't leave it like this or your coil would receive power all the time and burn up). But it can help with your diagnosis. Try and measure the voltage at the positive terminal on the coil while the engine is cranking over and see what its dropping down to.

The supplier of my pertronix unit told me that the module needs 5V to 'trigger' the spark, so on a 6V system you can't afford to lose ANY voltage at all, even with a 6V system in absolutely tiptop shape its a pretty close thing. Less than 5V and you just get nothing - which is why it doesn't fire up. With breaker points, even with a voltage drop, you still get some class of spark and its enough to get started with.

I found a replacement battery helped a lot (but my old battery was VERY tired), but has not cured the problem completely. If the car has been sitting for a couple of days or is cold, I still have to use the jumper wire trick. If the car is warm and has been out and about during the day, it starts up fine with just the ignition switch.

I also found that running an additional earth cable from the lower starter motor mounting bolt to the battery earth post helped a bit too. Make sure your gearbox to chassis earth strap is in good shape and that the connections are clean. In fact go over all your old wiring and ensure the connections and grounds are clean and bright - this seems to be mandatory for a functional 6V system anyway.

In my case, the ignition switch wasn't the problem but my reading (and Speedy Jim's suggestion above) indicated that the switch is often a cause of voltage drop or resistance in the starting circuit. They just get old.

I have found that the jumper wire from the regulator to the coil starts the car immediately every time and I am now thinking about trying to hardwire it in permanently with a 'momentary-on' switch so that I can deliver the extra squirt of volts required by the pertronix just during cranking to start the car and then release it without having to dive back into the engine bay whenever I want to start the car. Its just not a good look ;-)

Even with the difficulties in running the electronic ignition on a 6V system, I'm delighted with its performance and wouldn't want to go back to points. As you say, once the engine is running it feels strong and smooth and the timing is rock steady.

Good luck!

This will really get Jan going....

You can hook a Ford 6V regulator (acts like the 12v hard start relay) near your starter and you don't worry about dropping below 6 volts.

Mario Vintage Werks resto

Aha! Methinks you have hit it!

By chance I have a sketch of what's needed:

The relay of course needs to be a 6V coil. A small one with a contact rating of 10 Amps would be adequate.

No extra wires need to be run; use the existing Blk wire in the loom which comes out in the engine bay to operate the relay.

An automotive-style circuit breaker could be inserted in the battery lead.

Speedy Jim

You can hook a Ford 6V regulator (acts like the 12v hard start relay) near your starter and you don't worry about dropping below 6 volts.

Is this not the that Gino mentions in his post?

His vehicle has obviously already had a voltage drop problem in the past which would have led to the hard start relay being fitted? Doesn't seem to have eliminated the problem though...

I appreciate that some folks view the hard start relay as a bandaid- fix over an existing problem and that one is better off fixing the cause rather than the symptom but I have been over my wiring and done all that I can do to refresh it. Short of a new wiring harness I don't know what else I can try. I wonder if 40 yr old wires just have an increased resistance?

I would fit a 6V hard start relay if I could find one.....! Anybody?

needed:

By golly, that looks like just the ticket. This looks like a solution all right, relay instead of switch.

Nice.

I'll give this a go then, thanks once again Speedy Jim ;-)

Gino, hope this solves your problem too.

Is this just in case the relay fries some day? What strength would be appropriate?

needed:

Well, it will protect against a short circuit (wire grounds to engine)..

BTW, I have a small stock of NOS 6V relays available. Small charge to anyone on this NG. E-mail me.

Speedy Jim

Speedy Jim, you have mail.

:-)

For anyone still following this, present stock of relays has been depleted :-(

ALSO: important note- When using a relay to "boost" Coil voltage, a small diode (1 Amp rating) should be inserted in the Blu lead to the dash "GEN" light.

Without the diode, feedback will occur *after* the key has been switched Off which will keep the engine running...and running...

This can also happen on 12V cars which have been equipped with electronic ignition.

The wiring for a 6V Generator car looks like:

Wiring for a 12V car with alternator looks like: Jim

I had this problem a few months ago - none of my car-freak friends had ever heard of a car with headlights on keep running after ign. switch turned off, and the headlight switch actually acting as the ignition on/off switch! I posted here and Speedy Jim gave me the above-mentioned advice. I installed the little inline diode and guess what......problem solved BIG Thanks to Speedy Jim for this and all the other top-notch advice he gives on this group. BIll.

Doesn't that ford relay/regulator draw more amps or same amount of amps as the solenoid on the starter? Solenoid on the starter will draw lots of amps at the begining when it shifts but then amp draw drops where as ford regulator will continue to draw hi as long as you have the key in the start position.

Ant> >

No, the Ford relay is not a mechanical solenoid like the VW.

The Ford relay only has to close a pair of heavy contacts to engage the starter motor. The heavy mechanical work is done at the starter shaft to "throw" the pinion gear into the flywheel.

Beginning in the 30's, Ford used a unique "Bendix" drive.

This from Wikipedia: The Bendix system places the starter drive pinion on a helically-cut driveshaft. When the starter motor begins turning, the inertia of the drive pinion assembly causes it to ride forward on the helix and thus engage with the ring gear. When the engine starts, backdrive from the ring gear causes the drive pinion to exceed the rotative speed of the starter, at which point the drive pinion is forced back down the helical shaft and thus out of mesh with the ring gear.

Jim

Hi Jim,

I was basing off Bob Hover's toolz part 11... Not sure if there were two kinds of ford relays...

Anton

Um, my 66 Ford starter relay is nothing but a mechanical solenoid with electrical contacts at one end of the moving plunger... plunger thingy moves against a spring when the electromagnetic field around it is activated, making the contacts short against stationary posts. Wait a minute.. that's how relays are ;D

The VW starter solenoid is nothing but a big relay. The Ford starter relay is nothing but a somewhat smaller solenoid.

Jan

the difference is the ford relay makes an electrical contact, the vw starter solenoid is responsible for mechanically moving the starter pinion into position...

The VW starter solenoid bridges the big electrical terminals at the back of it just the same as the Ford unit.... it's an electrical relay as much as it is a mechanical lever.

Jan

Yeah, but what you are missing is the fact that it requires a HUGE current for the VW solenoid to move the pinion gear out (~35 Amps initially). I don't have one handy, but perhaps you would be so kind as to measure the Amps draw on your Ford "relay". I bet it is under 5 Amps.

The whole point of this oft-repeated discussion is that the VW Ignition switch (and lengthy wiring path) is poorly equipped to handle the current required by the starter solenoid. And the frequent switch replacements needed by owners attests to this.

Jim

Frequent, as in every 30 years or so?

:D

Yea, I agree the design could be better.

Jan

the issue was "current draw".... it take much more current for the vw(mechanical AND electrical) solenoid than it does for a purely electrical solenoid/relay....