coil resistor smoking

[SIVAllan]

I noticed the coil resistor smoking, and a burned distributor cap. Now of course the engine won't start.

Will find a cap tomorrow, but no clue about the smoke.

Anyone have an idea on this .. ??

Earlier, a new coil with built-in resistor died while I was driving. I replaced it with a used Lucas coil from eBay that came with a resistor.

Any ideas would be appreciated.

Thanks in advance,

Allan

 

[Green67Alpine]

Allan, I got a couple used dizzy caps(I think ones fairly new) here if you want to try them, I don't believe I've got a resistor though, but then there's a few boxes of stuff here and I've not much of a memory.

Tom j

 

[SIVAllan]

Tom,

Thanks!

I have a newer distributor with a different cap. So gotta get a cap for the new distributor.

I DO have some old distributors, of the factory stock variety, and a new cap or two for that model.

Guess I'll either turn up a new cap, or drop in an old distributor.

Still concerned about the resistor smoking. What could be the cause, or maybe it's the wrong resistor. It looks shorter than the one that came on the car, but beyond that I have no clue.

Allan

 

[64beam]

Hi Allan,

I'm not sure what value the resistor should be (someone can confirm it for you), but make sure the resistance is correct and make sure the coil has the correct internal resisitance (should be approximately 1.2 ohms from memory). If you has a 3 ohm coil, the resistor is not required. If it is 3 ohm, it may be the cause of the smoking resistor. My Alpine is running a 3 ohm coil (no resistor), but that is how it has always been since I have owned it.

Good luck,

Regards, Robin.

 

[Bill Blue]

Allan, I "refurbished" an original resister, the lowest value I could get was 1.7 Ohms. I think that is very close to what you need.

Why the damn thing would start smoking is beyond me, unless you had a dirty rivet connection (high resistance) with a little oil on it. I soldered the riveted connections on mine. But even with high resistance at the resister, why would the dizzy cap get burned??? Did the alternator go bananas and start cranking out 20 or so volts? Killing a coil, now this, makes me wonder.

Bill

 

[SIVAllan]

Robin, Bill,

Thanks.

I'm a little leery of the ignition system, given a dead coil and now a smoking resistor.

If there was a spike I didn't 'notice it at the time.

But maybe the resistor is wrong for the coil. I have 3 short ones that I think are off of SVs, and the one long one that came on the SIV.

Is there a difference between stock SV resistors and stock SIV resistors .. ??

The coil that came on the car is small and chromed, a little rusty. That coil was paired with a long resistor, which I "assume" is stock for a SIV.

Other coils in my box of bits are Lucas, but all I know is 12 volt. Bad guess on my part to assume they all matched .

The parts car had an aftermarket coil, I'd have to find it now, paired to a short resistor.

Allan

 

[sammaw@bellsout]

Where was the dist cap burned?

 

[sammaw@bellsout]

Don't wory too much about the lenght of the resistor. What you should be looking for is one that is in the range of 1.6 to 2 ohms. You can check this with a multimeter palced on the terminals with the leads removed. The car should be wired to start with the full 12 volts, and what the resistor does is reduce the voltage while running to around 6 to 7 volts to let it run cooler.

I had smoking on a new resistor, but it quit shortly. I think it burned off coatings on the wire.

 

[SIVAllan]

Where was the dist cap burned?

The cap was burned in the center.

 

[sammaw@bellsout]

Was the lead from the coil to the cap burned as well? If so, if the the burn is localized to one spot it probaly means you were getting poor or almost no contact, which lead to arcing and a hot spot.

 

[Bill Blue]

Allan, a philosophy I have adopted in the past few years is "If it makes absolutely no sense, check the grounds". I would start with a wire, screwed onto the dizzy body and running to ground. This is something that cannot hurt and might help.

I know I have mentioned this to you before and you might say I'm being hard headed and persistent. Well, you may be right. I don't understand how, but I've heard of a poorly grounded dizzy burning up points. If so, what else is it capable of?

Bill

 

[SIVAllan]

I'll check that with daylight but don't recall a problem with the lead.

I'll also attach a ground wire running from one of the bolts in the distributor
housing to the chassis.

Might be maybe somehow related to the carbs - incorrect spark .. ??

 

[Bill Blue]

I'll check that with daylight but don't recall a problem with the lead.

I'll also attach a ground wire running from one of the bolts in the distributor
housing to the chassis.

Might be maybe somehow related to the carbs - incorrect spark .. ??

Allan, after screwing around with the Weber for a couple of weeks and finding a bad capacitor and bent dizzy shaft at the heart of most of the problems, I can say for sure a substandard spark can cause all sort of "carburetor" problems. Especially at high loads or rpm.

This stuff was either fresh rebuild or fairly new, definitely not in the "replacable" category. At times like these, trust nothing to be good.

Bill

 

[64beam]

Hi,

The ignition circuit is basically two resistors in series. The ballast resistor at 1.6 to 2 ohms and the coil at approximately 1.2 ohms (primary side). The current passing through the circuit would range from approximately 3.75 to 4.3 amps (6 to 8.5 Volts across the ballast resistor as previously mentioned). If your ballast resistor has a short circuit, the current in the circuit jumps to 10amps and you have over twice the current through your coil continuously. If you have poor connections at the resistor, this would increase the resistance and lower the voltage to the coil further causing excessive heat at the ballast resistor and possibly cause damaged to it.
Make sure that all connection are clean and tight and that all the components are correct and you should be right.

Regards, Robin.

 

[V_Mad]

I am confused here, but please enlighten me if I am mistaken. My Alpine wiring schematic does not show a ballasted ignition system on any series (only the Tiger has one). There is no benefit to fitting one without the additional starter solenoid connection which applies full volts to the coil on starting.

That aside, you need to fully check out your ignition system wiring to make sure it is all connected properly before trying to run it. Switch on the ignition and measure the volts between the ballast and the coil; this should be about 6 volts with points closed (connect a short to ground if points are not closed). If the ballast is smoking because it is getting overheated, there must be a permanent short to ground (at the coil/ballast junction) which is overloading it.

But I would eliminate the ballast and start over with a new 12 volt coil. Check that when points close, the volts at the points go from 12 volts to zero (or less than 0.5 volts).

 

[Bill Blue]

Chris, virtually every Alpine I have looked at has a ballast resister and they all are the same design. As for the few that did not, I'd wager they had been removed. Maybe it was just the North American market, but the usual setup for the period was a resister with no bypass circuit. Most commonly (GM and Ford), the resister was the coil to distributor wire.

Bill

 

[puff4]

Yep, I agree, Bill. My SV has a ballasted ignition coil, too, and I have a nearly completely original Alpine. I believe all North American Alpines came with ballasts.

However, I believe there is a bypass in the original system. When you have the ignition switch in the 'start' position (i.e. you're cranking the starter) the power bypasses the ballast and goes directly to the coil, giving you an extra 'hot shot' in terms of spark, and making up for the voltage drop while the starter is drawing a significant amount of power. When the switch is released and placed in the 'ignition on' position (i.e. 'run', not 'start') power is then switched to go through the ballast to the coil and enable normal running.

To test for proper ballasting, try unplugging the ballast and you'll find - if it's correctly wired - that the car will start (while in 'start' mode) but then quit as soon as you release the switch (while in 'run' mode).

 

[V_Mad]

Chris, virtually every Alpine I have looked at has a ballast resister and they all are the same design. As for the few that did not, I'd wager they had been removed. Maybe it was just the North American market, but the usual setup for the period was a resister with no bypass circuit. Most commonly (GM and Ford), the resister was the coil to distributor wire.

Bill

Thanks Bill. It is not shown in the UK wiring schematic., so it must be a special for N. America. How is the ballast bypass switched, is it a contact on the solenoid (as on the tiger)? If so, your solenoids must be different to UK as well.

 

[SIVAllan]

PIcked up a dizzy cap and quizzed the parts-house guy.

Parts guy believes that no resistor is needed for the 25D dizzy.

I put on a coil he recommended as matched to a 25D, and
put on my old 25D dizzy, engine starts again, but timing
is way way off.

I had been using a new 45D dizzy, but parts guy said that the 45D
model needs a 6 volt coil and a resistor (not the 12 volt coil I had
been using.)

I hope you'all who understand this can get it straightened out .. .

Allan

 

[RootesRacer]

How is the ballast bypass switched, is it a contact on the solenoid (as on the tiger)? If so, your solenoids must be different to UK as well.

The ballast isnt bypassed on the alpine, you just get a weaker cranking spark.