Home 
> Jensen Healey & Jensen GT Tech > Ignition > Ballast Resistor?

 Moderated by: Greg Fletcher  
AuthorPost
Ben Friedman
Member
 

Joined: 04-12-2005
Location: Piedmont, California USA
Posts: 5
Status: 
Offline
I am currently converting to a Pertronix Ingnition system with a Flamethrower coil (by the way, thanks to everyone for helping out on my previous post), and have been following everyone's advice carefully.  Even so, I seem to be stuck.  What is this ballast resistor that I keep hearing about, and where is it?  I have traced both wires that go to the positive side of my coil: one comes from the solenoid, and the other goes through the firewall (with no sign of a resistor), and then disappears somewhere in the wiring harness behind my instrument cluster.

Is it possible that I don't have a ballast resistor?  And if so, where should I connect the other wire of my Pertronix Ignitor to?  Why does everything that seems so simple always turn out to have so many hidden problems?

Thanks,

Ben

Judson Manning
Member


Joined: 03-14-2005
Location: Atlanta, Georgia USA
Posts: 406
Status: 
Offline
Ben,

Pre-1974-1/2 cars have a physical resistor which looks like a small 1/2"x1/2"x2" white brick mounted next to your coil.  Later cars have a Nichrome wire built into the wiring harness which accomplishes the same thing.

Assuming you do have either a ballast or the Nichrome wire, it can be checked easily:  If you start your car and put a Volt Meter on the + side of the coil while it's running, you should find you ony have 9-10VDC instead of the expected 12-14VDC. 

The JH is actually wired such that full battery voltage is supplied to the coil when the starter is engaged (the extra wires on the coil and the starter).  This helps cold start-up.

Installing a Lucas 'sport coil' or other type of coil that has an integral resistor w/o removing the ballast resistor causes only about 7VDC to reach the coil.  Is it a problem?  For a bone-stock car running in perfect condition down to the Grocery Store...no it's not.  However, once you up the compression, open the plug gap, or require any real work from the engine, 7VDC won't be enough and you'll be plagued w/ missfires.

Jensen Healey
Super Moderator


Joined: 03-11-2005
Location: San Anselmo, California USA
Posts: 976
Status: 
Offline
Ben,

Did you get it working? Remember, the Pertrinix is just a switch. The white hot wire from the ignition switch goes through the tachometer and ballast resistor (or resistor wire) to the + side of the coil.

I could be making a road trip to the East Bay this weekend if you need an extra set of eyes.

Kurt Housh

Ben Friedman
Member
 

Joined: 04-12-2005
Location: Piedmont, California USA
Posts: 5
Status: 
Offline
Sorry for taking so long to reply, but my internet has been down for the past couple of days.  It looks like I have run into a new problem though.  I have the Nichrome wire type of resistor, meaning that I can't just simply plug the Ignitor wire around it to bypass it.  Does this mean that I need to rewire the Nichrome wire with a normal wire (thus eliminating the resistor), all the way from the tachometer to the coil?

Thanks,

Ben

Jensen Healey
Super Moderator


Joined: 03-11-2005
Location: San Anselmo, California USA
Posts: 976
Status: 
Offline
No, just hook it up and get the car running. You can bypass the wire later if needed.

Leave the white with slate tracer connected to the + side of the coil. It will supply 12v on start up and won't hurt anything after you bypass the resistor.

 

Kurt Housh

JH 13148

Last edited on 04-18-2005 01:58 pm by Jensen Healey

Ben Friedman
Member
 

Joined: 04-12-2005
Location: Piedmont, California USA
Posts: 5
Status: 
Offline
Alright, I've finally put the whole thing together, and it works fantastic.  The timing hasn't shot off by 30-something degrees as everyone has been telling me, but instead just needed a run-of-the-mill adjustment with a timing light.  All I have now is to bolt back on the air filter (or is it a muffler?) and take the 'ole Jensen for a spin.  Thanks to everyone again for the help.

Thanks,

Ben

George
Member
 

Joined: 04-05-2005
Location: Boyds, Maryland USA
Posts: 88
Status: 
Offline
Following the advice in this thread (thanks everybody), I hooked up my Flamethrower coil with the ballast resistor wire left in place. (I have the red wire with the cloth covering rather than the little brick).  But, I was wondering, if this is left in place, doesn't it effect the output of the coil, so that you don't get whatever advantage the higher output coil is supposed to provide?  And to get around it, do you have to run a new wire all the way back to the ignition?

I'm not complaining mind you, I'm happy it works at all!  these are great cars.

Joel
Member
 

Joined: 07-01-2005
Location: San Diego, USA
Posts: 184
Status: 
Offline
It seems to me that if someone answered George's question - it would help me out!! I'm off to check what voltage I'm getting on the coil but I'm guessing it twill be low. . .

Joel
Member
 

Joined: 07-01-2005
Location: San Diego, USA
Posts: 184
Status: 
Offline
I was correct. At idle I'm getting 9.5 volts max. I'm playing by myself so even with my unsteady hand and the flashlight. .it was 8.5 to 9.5. If I rev up the engine - I get 11.5ish. The battery is up above 12 if you're wondering.

Mark Rosenbaum
Member


Joined: 03-12-2005
Location: Kingman, Arizona USA
Posts: 532
Status: 
Offline
Yes, the ballast (whether white ceramic brick or funny wire) reduces the voltage applied to the coil.  The original factory coil, whether Lucas or Delco, requires a ballast.  For all other coils, the manufacturer should state whether or not a ballast is required.  If you don't know, it's always prudent to assume a ballast is required, until and unless you learn otherwise.

Using a ballast with a coil that does not require one does in fact reduce the maximum possible high voltage available.  However, if the spark plugs will fire at a lower voltage, the system will never develop the maximum, and you will not see much difference between the 'high performance' coil and the factory one.  Where the 'high performance' coil does provide a benefit is in the total energy it can deliver to a spark.

If a particular coil type requires a ballast, leave one in place.  If a particular coil type does not require a ballast, then the ballast may be bypassed or removed.  Bypassing the wire type ballast does in fact require adding a wire from wherever it starts, to the ignition coil.

Coils that do not require a ballast do not need the extra wiring that runs from the starter solenoid to the coil.  This wiring can then be disconnected and tied off, though it's prudent to leave it in place in case a conventional coil is installed at some later date.

 

Joel
Member
 

Joined: 07-01-2005
Location: San Diego, USA
Posts: 184
Status: 
Offline
And the 60,000 question is - does the Pertronix Flamethrower coil need a ballast resistor?

Mark Rosenbaum
Member


Joined: 03-12-2005
Location: Kingman, Arizona USA
Posts: 532
Status: 
Offline
Good question, and one which a careful reading of the Pertronix website neglects to answer directly, shame on them.  However, they do mention in their online PDF catalog that there are two versions of the basic Flamethrower coil, one having 1.5 ohms resistance, the other 3.0 ohms resistance.  You'd have to read the fine print in the catalog to determine the part numbers for each version.

Since a typical ballast resistor has about 1.5 ohms resistance, I surmise the following:
(1) The 1.5 ohm coil is for use in cars with a ballast resistor;
(2) The 3.0 ohm coil is for use in cars without a ballast resistor.

I do caution that this is merely an educated guess on my part, but it is one I'd rely upon if it were my car.  To be absolutely certain, you could contact the company and get them to make some sort of commitment for your particular circumstances.

Joel
Member
 

Joined: 07-01-2005
Location: San Diego, USA
Posts: 184
Status: 
Offline
Mark:

I come to the same conclusion. The website doesn't have ANY info for someone to contact.

My coil is 3.0 ohms.

I should be able to run a wire from anywhere that is hot when the ignition is on and off when it's not - yes? That way I can test it out with the lovely wire that the PO had run from the fuse box across the engine compartment. . .

Long term I suppose I should run a new one from where ever the red one comes from - I assume the tach?

And yes - I do realize that it is a sixty FOUR thousand dollar question - even though I'm too young to have appreciated that silly television show.

Thanks Mark.

Mark Rosenbaum
Member


Joined: 03-12-2005
Location: Kingman, Arizona USA
Posts: 532
Status: 
Offline
For testing, yes, anywhere that's hot when the ignition is on will work.  But for actual driving, you'll want the tach to work, so you'll need to hook things up as follows (ignoring the various connectors):
*  A wire from the ignition switch to the tach.  This can be the original wire.
*  A wire from the tach to the coil [+] side.  This can be the original wire that used to go from tach to ballast.  If you have a Pertronix, its red wire also goes to the coil [+] side.
*  A wire from the coil [-] side to the distributor.  If you have a Pertronix, this is its black wire, but if you have points, use the original wire instead.

As previously noted, I'd guess that you won't need a ballast with the 3.0 ohm coil.  And without a ballast, you don't need to use the wiring that comes from the starter solenoid.

The TV show you mention was based on a Depression-era radio show called 'The $64 Question.'  Before my time, actually, but apparently a dollar was worth rather more than it is today.

 

Joel
Member
 

Joined: 07-01-2005
Location: San Diego, USA
Posts: 184
Status: 
Offline
the car is running quite smoothly - on 2 cylinders. it's running so nicely on those two cylinders it will sit and idle.

no fire on the front 2 cylinders. not even at higher rpms (as evidenced using the timing light to see what's firing). i did get blip at one point but it quickly stopped.

maybe a new distributor?

i'm stumped.

Mark Rosenbaum
Member


Joined: 03-12-2005
Location: Kingman, Arizona USA
Posts: 532
Status: 
Offline
It's almost certainly something strange with the distributor.  Check the following:

1.  Exchange the plug wires between a good cylinder and a bad one.  If you now get spark in what was the bad one, install a new plug wire set.

2.  Using a voltmeter or test light, verify that the points or Pertronix gadget switches on and off for each of the cylinders.

3.  Inspect the inside of the dist. cap and ensure that you do in fact have a metal terminal for each of the spark plug turrets.

4.  If you have points, check the points gap for each of the cylinders.

5.  Pull off all four plug wires, and connect them to four plugs whose shells are in contact with the engine.  Key on, crank the engine, visually check for spark at each plug.

Joel
Member
 

Joined: 07-01-2005
Location: San Diego, USA
Posts: 184
Status: 
Offline
Good advice.

1) The plug wires are new - but there could be a problem I guess - I'll swap some wires and see what happens.

2) I'm not sure how I'd go about checking the Pertronix switch. It's obviously working on 2 cylinders. I guess I could use the voltmeter on the leads to the coil. . .

3) Rotor and cap are brand new - no probs.

4) Pertronix

5) No fire - no juice going thru the wires. Will check #1 but don't believe the wires are the problem.

I'm waiting for Bean and Delta to get back w/ me on prices for a new distributor.

Mark Rosenbaum
Member


Joined: 03-12-2005
Location: Kingman, Arizona USA
Posts: 532
Status: 
Offline
Joel,
The Pertronix gadget is a magnetically activated solid-state switch.  From the user's point of view, it works exactly like a set of points, with none of the faults mechanical points have, and only a few inherent faults of its own.  This means that you can test the thing just like a set of points:

* Equivalent of points closed = (almost) no voltage present on Pertronix black wire, current flow of several amps through the device.

* Equivalent of points open = 12 volts (nominal) present on Pertronix black wire, no current flow through the device.

The plastic bit that fits over the distributor cam is supposed to have a magnet for each cylinder.  If one of these is missing, broken, or extremely weak, the Pertronix won't be triggered, and you won't get a spark for the associated cylinder.  If the magnet carrier can fit over the distributor cam in more than one way, try a different orientation and see if the trouble moves to different cylinders.  If so, contact Pertronix for a replacement magnet carrier.

Another thing you can try is to rotate the engine so the distributor rotor is aligned with the turret for one of the non-firing cylinders.  Disconnect the Pertronix black lead from the coil.  With the ignition on, you can then make a spark by momentarily connecting the [-] side of the coil to chassis ground (touch only the wire's insulation yourself, or you'll get a shock).  Trace the spark from coil to distributor to spark plug, and perhaps this will reveal the problem.

If all else fails, put the points and condenser back in, get the thing running properly, then reinstall the Pertronix.

 

Joel
Member
 

Joined: 07-01-2005
Location: San Diego, USA
Posts: 184
Status: 
Offline
Damn, this is turning into quite a hassle. But, it's a hobby not a car - right? I must admit I've learned a lot about ignition systems. . .

Ok, still no go on front two cylinders.

A quick run down:

I checked that there are indeed 4 distinct 'on - off' points. I put my voltmeter between the black wire and the coil, took off the dist cap and turned the engine over by hand (I'm getting pretty good at that. . ). As the rotor moves around the dist there are 4 distinct 'off' and 4 distinct '11.5+' switches. Ok - I guess the Pertronix is working.

I put the car on TDC and made sure that #1 does indeed have the rotor pointing towards it. I then (I think this is overkill but did it anyway) adjusted the rotor so that at TDC I would have current flow between the pertronix black lead and the coil. I realize that the timing will need to move to a few degrees before TDC but at least I should be close - yes?

Still no fire to the front 2 cylinders.

Changed the cap back to the old - no change.
Swapped plug wires around - no problem with my new wires.

The easiest way to check if there is fire is to use the timing light to see which wires have fire. Of course 1&2 have none and 3&4 are fine regardless of plug wires used.

I don't think it's the distributor - at this point (in my understanding) the dist is basically just a mechanical part that spins around to open and close the circuit. As long as it's spinning it's doing it's job.

But, I don't know what else to check. I don't have a points /condenser set to put in or I'd try that.

I have to say that Ken at Dave Bean was extremely helpful (or at least he tried to be). Unfortunately his price for a new distributor is 150 bucks more (398 vs 245) than Delta. The guys at Delta are nice enough but Ken seemed to really know his stuff. One time I called Delta and bought another (unrelated) part. When I asked the guy a question he told me 'I don't work on em. I just sell parts for em'. I did get a nice e-mail comment today from Delta regarding the dist - he told me he didn't think that was the problem - and I concur.

Anyway, any more ideas? I'm sure I'm missing something simple somewhere.

Rotor??? I can't find the old one to put back on but that seems too simple. ALl it has to do is turn and make the spark jump to the cap. If it does it for 2 it should do it for 4. . . .

Last edited on 09-22-2005 10:59 pm by Joel

Mark Rosenbaum
Member


Joined: 03-12-2005
Location: Kingman, Arizona USA
Posts: 532
Status: 
Offline
It sounds like things are good right up to the spark plugs.  Certainly that's about all that's left.  ISTR that you mentioned checking the plugs, but perhaps I mis-recall?  If the center electrodes are shorted out somehow, that might give the symptoms you describe.

Other than that, I too am completely at a loss.

Joel
Member
 

Joined: 07-01-2005
Location: San Diego, USA
Posts: 184
Status: 
Offline
I can swap plugs but - even if the plugs aren't firing - there should at least be fire thru the wires.

Mark Rosenbaum
Member


Joined: 03-12-2005
Location: Kingman, Arizona USA
Posts: 532
Status: 
Offline
That's correct only if the plugs are not shorted.  A shorted plug will not allow the development of a voltage high enough to make a spark, trigger the timing light, etc.

As you noted, it's likely there's somethign simple and basic that's been overlooked, but I'm completely at a loss to know what it might be.  Perhaps if you start from the beginning as if the problem were brand new you might notice something....

Joel
Member
 

Joined: 07-01-2005
Location: San Diego, USA
Posts: 184
Status: 
Offline
I think i'm going to buy points and condenser and start from there. if that doesn't work. the only thing i can think of is to buy an new dist and see if that makes a difference.

i will switch plugs and see what happens.

i'm baffled and don't know what taking it to a professional would help. . .

just remember it's a 'hobby' not a car.. .

Brett Gibson JH5 20497
Member
 

Joined: 03-17-2005
Location: Hilton, New York USA
Posts: 712
Status: 
Offline
Have you checked to see if you may have crossed the positive and negative wires on the coil, that will give you problems like these......

Brett

Joel
Member
 

Joined: 07-01-2005
Location: San Diego, USA
Posts: 184
Status: 
Offline
Brett:

I don't think so - but I'll check again. I hooked it up the way it was wired before I put in the new coil. BUt, that doesn't mean that the PO(s) didn't have it wired up incorrectly in the first place. Actually that wouldn't suprise me - seeing some of the stuff he did to the car. I switched everything out b/c of intermittent spark. Now it's zero spark.

I'll carefully trace all the wires again. That's a good suggestion. I'm thinking that it's something simple like that. . . .

Let's see - off the top of my head (I'm at work and not near the car):

On the positive side: one wire from the Pertronix, one mysterious red wire that has the 'resistor' built in and goes thru the firewall - probably to the tach, and one (should be unecessary now in my understanding but I left it for posterity as it was there on the original - I've run it w/o as well) that comes from the wiring harness to give extra kick when starting.

On the negative side: One wire from the Pertronix and one from the harness that sits right next to the aforementioned wire for extra kick when starting.

Again, I'm not at the car right now but that sounds about right. I think Mark gave me some wiring info in an earlier post and I checked it out. But, I'll admit I have been giving some credibility to the previous wiring and maybe I should just start from scratch.

Thanks again!

Last edited on 09-23-2005 03:55 pm by Joel

Brett Gibson JH5 20497
Member
 

Joined: 03-17-2005
Location: Hilton, New York USA
Posts: 712
Status: 
Offline
Joel, I think most people on this list at one time or another have shared your experience of wanting to throw the towel in due to frustration, when I succumb  to the effect's I usually just step away for a day or two and give it a bit of thought, plus a few beers.

I dont mean to insult you but what works good for me is that I go back and check all the basic's, top dead center on #1, timing marks all ligned up etc etc, making sure the fit and function make sense, and I'm comfortable with what I see, having a extra wire hanging about that I'm not all that sure of ( function wise ) would give me pause for concern.

And one last thought, are your grounding straps / wires making a good contact, not sure about the Petronix but my Alison was giving me trouble due to a bad ground.

Good Luck    Brett.

John Finch
Member
 

Joined: 08-01-2005
Location: Minneapolis MN
Posts: 120
Status: 
Offline
I have purchased but not installed a Pertronix coil and electronic ignition. I called Pertronix and they told me that with both units (coil and elec dist)  no ballast resistor is required. If you have a non Pertronix coil then he recommended the resistor. I used the phone number on the instructions. Hope this helps.

Joel
Member
 

Joined: 07-01-2005
Location: San Diego, USA
Posts: 184
Status: 
Offline
I called pertronix a couple of days ago and got the same response. I was waiting to post until after I installed the brand used dist I have coming from British Masters. I'll give ya'll the low down after I get it in.

Joel
Member
 

Joined: 07-01-2005
Location: San Diego, USA
Posts: 184
Status: 
Offline
Update. Thanks for all the comments guys.

I was being a bit flippant about not knowing all the wires on the coil. I actually have a pretty good idea of what they are all for :-).

I too called Pertronix. Ballast resistor not necessary for any of their coils.

I replaced the distributor with a brand used one from British Masters. I had gotten all four cylinders firing - but when the oil pressure built up - the dist popped out!! The broken rim wasn't enough to hold it in place - especially with the crappy clamp I had. So, I replaced it and now she's running on all 4.

Coupla things:

Before I do anything I'm going to replace the tach wire so I'm getting enough juice.

The original pulley with the timing marks is not on the car. The new and improved pulley has a 'scratch' on it to indicate timing. At TDC *1 the scratch did line up at 0 on the gauge.

When timing the engine - at 10 deg advanced the motor will barely run. In order to get it to idle I have to advance the timing to 30+ degrees. I'm guessing that I'm moving to the next plug instead of the one I thought was number one. Anyone agree w/ me? I'm thinking I'll move all the wires one plug forward and see if that takes care if it.

She's not running right - lousy acceleration from about 1500-3000 rpms. But at least she's running and I drove her today! She idles pretty well - that's a first since I bought the car. Also, there are carb troubles b/c the front carb seems to throw out some atomized fuel when I rev her up - and the rear one doesn't. I'm closer to getting the ignition gremlins tossed out. Thanks to all for the comments.

Mark Rosenbaum
Member


Joined: 03-12-2005
Location: Kingman, Arizona USA
Posts: 532
Status: 
Offline
Congratulations on your success in dealing with a particularly difficult set of problems.

I'm curious about your 'new and improved' crank pulley.  What is the 'gauge' you're using with it?  How certain are you that the 'scratch' mark on the pulley actually represents TDC for the #1 (front) cylinder?  If this mark does not accurately indicate TDC, your timing issues may disappear once you correct the situation.

Improper cam timing can also cause all sorts of performance issues.  Once you know for certain where #1 TDC actually is, verify that your cam timing is correct (i.e. the index marks on the two cam gears should align when the #1 piston is at TDC for the start of its power stroke).  If a PO made an error here you'll need to correct it.  But don't guess about TDC as there's a serious risk of valves hitting pistons and bending, if you get the cam timing too far off.

Your low-speed performance issues sound like carb problems in addition to whatever ignition and/or cam timing problems you may still have.  The cloud of fuel mist you describe is normal if it occurs when the throttle closes after one revs up the engine -- it's an 'echo' that results when high-speed gas flow is reflected back from the closed throttle and passes out the carburetor throat into the atmosphere.  This phenomenon occurs in all engines but happens to be particularly visible with Strombergs.  Having it appear at only one carburetor suggests that there's something out of sorts with the other carburetor.

 



UltraBB 1.172 Copyright © 2007-2011 Data 1 Systems