Ballast Resistor Bypass

[Duff71Riv]

Hi all,

Quick wiring question

My 65 Corvair I am selling soon has a new electronic ignition I put in place of the points. It ran bad... I hotwired 12V from the battery directly to the coil.... it runs flawlessly.. my ballast resistor is not giving the coil enough voltage. 

- What would be the best way to bypass the ballast resistor? Has anyone had to do this before? 

Thank you for any help!

Ryan 

 

[John348]

How was it running before you installed the electronic ignition? My answer is put the points back in

[Duff71Riv]

1 minute ago, John348 said:

How was it running before you installed the electronic ignition? My answer is put the points back in

Awful

i didn’t buy a $250 kit to put back in points HAHA. I dont dislike points. My riviera still runs them it runs great gap and dwell up to spec. I just wanted to upgrade and it runs amazing with the new ignition system when it has 12V. An electronic ignition has no wear contact areas UNLIKE points I (or future owners) wont have to worry about adjusting them every 2000 miles.  

[Bloo]

Get out the Corvair wiring diagram. I'm not sure how much different the Corvair is from other GM of the period, engine in the back and all, but most of them have NO switched 12 volts under the hood except the resistor wire. So, run a nice big wire from under the dash. Be sure to fuselink it or fuse it at the dash end, so it doesn't burn your car down if it gets pinched.

 

Or, you could add a relay, and just trigger it from the resistor wire. If you do that you can grab power at the positive cable on the starter. Then, you need to run a little wire up to the front to power your generator/alternator idiot light from, instead of powering it from the ignition switch like the factory did. If you don't do that, the engine will not shut off. That method is probably a little safer, and also would get you a little more voltage at the coil and take some load off your ignition switch. I would fuse the little wire back at the relay end.

 

Either way you need to run wire to the front.

 

 

[John348]

I would look at the coil, it could be a weak coil. If it ran poorly with points (at what is presumed to be six volts) and the electronic ignition system runs poorly as well, and improves at a full 12 volts, I would remove the by-pass and check the voltage at the coil. I also would check the primary polarity connections on the coil. 

[rocketraider]

Pertronix are designed to run on switched 12v. Or the ones in the Hurst/Olds and Toronado are, but they were installed nearly 20 yr ago. I was lucky that both of them had switched 12v cavities in the fuse block.

[Frank DuVal]

Adjust the points, sell the car. I can make any Corvair run very well on points. The new owner can modify if he/she wishes.

 

Did you try to fix the problem before you threw money at it? Worst case would be simple rebuilding of the points plate if the pivot was worn. Otherwise it is just put in new points. Rock Auto has lots to choose from.

 

But, what Pertronix cost $250?🤔   $250 buys a lifetime supply of points, and no rewiring/modification of the car needed. 

 

Remember the instructions, carry the old point plate and points/condenser in the glove box for when the electronic module fails on the road....😆

 

Powerglide or manual transmission? There is discussion on corvaircenter.com/phorum about which Pertronix is better with Powerglide, as one of the models does NOT idle well with the low speed of the Powerglide. I think this is also the one that requires full 12 volts to run. You have to add a bypass wire from the engine wiring harness/body wiring harness  connector to the + of the ignition coil. Do NOT wrap this modification with electrical tape, use proper harness tape, or be forever getting sticky crap on everything.

 

 

[Frank DuVal]

1 hour ago, Bloo said:

Either way you need to run wire to the front.

 

It's a Corvair. All the power you need is already in the engine compartment. 

 

Except for the very early turbo models, the ballast resistors are resistor wire in the engine wiring harness, like most every GM car of the period.

[Duff71Riv]

9 hours ago, Bloo said:

Get out the Corvair wiring diagram. I'm not sure how much different the Corvair is from other GM of the period, engine in the back and all, but most of them have NO switched 12 volts under the hood except the resistor wire. So, run a nice big wire from under the dash. Be sure to fuselink it or fuse it at the dash end, so it doesn't burn your car down if it gets pinched.

 

Or, you could add a relay, and just trigger it from the resistor wire. If you do that you can grab power at the positive cable on the starter. Then, you need to run a little wire up to the front to power your generator/alternator idiot light from, instead of powering it from the ignition switch like the factory did. If you don't do that, the engine will not shut off. That method is probably a little safer, and also would get you a little more voltage at the coil and take some load off your ignition switch. I would fuse the little wire back at the relay end.

 

Either way you need to run wire to the front.

 

 

Thank you! I like that relay idea Ill try to steal 12V from the starter

[Duff71Riv]

8 hours ago, Frank DuVal said:

$250 buys a lifetime supply of points, and no rewiring/modification of the car needed. 

My auto teacher who helped me get 9 ASE certs recommended I do it. He does it on all his classics. He has about 25, I respect his opinion. I'll ask him for help after hes back from surgery. 

[Frank DuVal]

Installing a Pertronix because you want to eliminate points is OK decision to make. We can disagree on if it is a good decision. Personal choice. But know the facts. Like the known issue of Corvair Powerglide cars not running well with certain Pertronix models.

 

Installing Pertronix to FIX a problem just adds another layer to problems to FIX. Unless the points themselves was the problem, installing the Pertronix at best would be a Band-Aid covering up the real problem, which will show up again. Now you have a car that still runs bad after adding a modification. Is it the wrong model of Pertronix? Is it the coil? Is it a bad connection to the factory resistor wire?

 

Lesson to learn is troubleshoot first!😉

[Duff71Riv]

32 minutes ago, Frank DuVal said:

Installing a Pertronix because you want to eliminate points is OK decision to make. We can disagree on if it is a good decision. Personal choice. But know the facts. Like the known issue of Corvair Powerglide cars not running well with certain Pertronix models.

 

Installing Pertronix to FIX a problem just adds another layer to problems to FIX. Unless the points themselves was the problem, installing the Pertronix at best would be a Band-Aid covering up the real problem, which will show up again. Now you have a car that still runs bad after adding a modification. Is it the wrong model of Pertronix? Is it the coil? Is it a bad connection to the factory resistor wire?

 

Lesson to learn is troubleshoot first!😉

Its a 4spd, not PG, my idle is not affected by the new ignition, I knew about hall affect sensors not working well in low rpm. The points were looked poor.. I know it would of been cheaper and simpler to do points but the idea sounded cool, I wanted the new experience ... :)

 

I will say again.. It runs great no issues with a lead from battery to coil, better than it has ever run before theres no more small stumble on the highway. I will just find a 12v hot in my harness... I was just curious if anyone had any tips on a good spot to splice if they had done it before. In hindsight I should of just asked where to splice in to get 12V and not mentioned anything ignition

 

[TerryB]

3 minutes ago, Duff71Riv said:

Its a 4spd, not PG, my idle is not affected by the new ignition, I knew about hall affect sensors not working well in low rpm. The points were looked poor.. I know it would of been cheaper and simpler to do points but the idea sounded cool, I wanted the new experience ...

 

I will say again.. It runs great no issues with a lead from battery to coil, better than it has ever run before theres no more small stumble on the highway. I will just find a 12v hot in my harness... I was just curious if anyone had any tips on a good spot to splice if they had done it before. In hindsight I should of just asked where to splice in to get 12V and not mentioned anything ignition

 

No, it’s ok to ask.  You will see in these types of discussion there are at least two schools of thought.  Most of us have seen points ignition working fine for years and no need to go to an electronic system.  Others like the simplicity of no points to set and adjust. A few have had the electronic fail on the road with no spare to be had so the points go back in.  Sounds like your initial issue was the condition of the points in your car as seen by replacing them with the electronic setup and getting a good running car.  These discussions are similar to the “what kind of oil should I use”.  Just enjoy the many thoughts on it and make your choice.

[joe_padavano]

I don't know anything about Corvair wiring, but obviously there are 12V sources available. The easiest place to tap into is the threaded BATT terminal on the back of the alternator. Run a fused wire from there to power the relay. That relay needs to be controlled by a 12V switched source. Just be sure that control wire is hot in both the START and RUN positions.

[Ronnie]

1 hour ago, Duff71Riv said:

 I will just find a 12v hot in my harness... I was just curious if anyone had any tips on a good spot to splice if they had done it before.

f you put a jumper wire across the terminals the ballast resistor to bypass it you will have 12 volts going to the coil. Is there some reason you can't do that?

[joe_padavano]

5 minutes ago, Ronnie said:

f you put a jumper wire across the terminals the ballast resistor to bypass it you will have 12 volts going to the coil. Is there some reason you can't do that?

 

Does a Corvair have a separate resistor like that, or a resistor wire that's built into the harness?

[Ronnie]

The photo I posted is from Rockauto and it is listed as fitting a '65 Corvair so I assume it is the correct ballast resistor Here is a link. Take a look and see if you agree.

 

  https://www.rockauto.com/en/catalog/chevrolet,1965,corvair,2.7l+164cid+h6,1322918,ignition,ballast+resistor,7052

[mike6024]

Yeah, where is the resistor in the stock configuration?

 

 

[joe_padavano]

5 minutes ago, Ronnie said:

The photo I posted is from Rockauto and it is listed as fitting a '65 Corvair so I assume it is the correct ballast resistor Here is a link. Take a look and see if you agree.

 

  https://www.rockauto.com/en/catalog/chevrolet,1965,corvair,2.7l+164cid+h6,1322918,ignition,ballast+resistor,7052

 

You want my entire list of stuff that the RockAuto catalog lists incorrectly, just for Oldsmobiles? How much time do you have?

[mike6024]

I also think that some coils are meant to be used with a circuit that includes a ballast resistor, and some coils are OK being used without a resisitor.

In other words, just because you remove the points in favor of electronic switching, doesn't necessarily mean you should remove the resistor and keep the same coil.

 

For my application, when I changed the distributor to electronic, the instructions said, must also install a Bosch Blue coil which needs no external resistor. So that seemed to imply that if the original coil was kept, and the resistor removed, that would be a misuse of the original coil.

 

 

[Ronnie]

3 minutes ago, joe_padavano said:

 

You want my entire list of stuff that the RockAuto catalog lists incorrectly, just for Oldsmobiles? How much time do you have?

It appears you are right. Looks like '63 was the last year for that ballast resistor. Here is some good info with lots of wiring diagrams that talks about installing the Pertronix ignition in a Corvair.

 

https://www.corvairforum.com/forum/viewtopic.php?t=9734

[mike6024]

This is the wiring diagram for 1965, but I can't make it out, too blurry. There is a dotted line going to the coil. What is that? Ground? Or a "resistor wire?"

 

 

[mike6024]

'65 Corvair has a resistor wire. Wire with built in resistance. For better heat dissipation I suppose.

[mike6024]

Maybe the original problem with this Corvair points system was actually a bad resistor wire. So it runs good with 12V applied directly to the coil. Would also have run good with the points if 12V would have been applied to the coil, thus bypassing a bad resistor wire.

 

 

[Frank DuVal]

14 hours ago, Frank DuVal said:

Except for the very early turbo models, the ballast resistors are resistor wire in the engine wiring harness, like most every GM car of the period.

 You guys should read what I write....  Separate ballast resistor mounted on rear frame rail was 1962/63 turbo models ONLY.  Edit: was dropped in favor of the resistance wire for 1964 Spyder and 1965/66 Corsa models.

 

14 hours ago, Frank DuVal said:

You have to add a bypass wire from the engine wiring harness/body wiring harness  connector to the + of the ignition coil.

OK, so I did not list the particular terminal in the connector, but there is where the +12 volt on with ignition switch on comes into the engine bay to operate the ignition system. A quick look in the wiring diagram will show the terminal. 

Edited March 8, 2021 by Frank DuVal (see edit history)

[Frank DuVal]

11 minutes ago, mike6024 said:

This is the wiring diagram for 1965, but I can't make it out, too blurry. There is a dotted line going to the coil. What is that? Ground? Or a "resistor wire?"

 

Yes, very blurry, but follow that yellow dotted line upwards from the coil + terminal, it goes to the starter solenoid two terminal connector, located at the left front of the engine bay, and right there in very blurry words : red-black-resistance-wire. That resistor wire is between the +12 volts switched ignition terminal of the engine harness/body harness connector and the two terminal starter solenoid connector. The purpose of this cross connection is the "bypass" where the starter solenoid provides +12 directly to the ignition coil when the starter is engaged from the battery directly without going through the ignition switch or resistance wire.

 

A bad connection in the wiring harness resistor wire is very rare, but it has happened. Usually at the end connections, not in the middle of the run. 

[Duff71Riv]

2 hours ago, Ronnie said:

It appears you are right. Looks like '63 was the last year for that ballast resistor. Here is some good info with lots of wiring diagrams that talks about installing the Pertronix ignition in a Corvair.

 

https://www.corvairforum.com/forum/viewtopic.php?t=9734

Thank you! I think this is what I will try to wire in Wednesday. 

[Frank DuVal]

That's it. I would just remove the terminal from the engine side connector and solder the new wire to it rather than cutting the body harness. Those Packard 56 terminals are easy to remove and solder to. Good time to clean all the terminals in that connector. Especially the #10 red wire's terminals. They cause lots of issues. 

 

You never answered what model points replacement equipment you bought. I can find no Pertronix that sells for $250. 

[Duff71Riv]

2 minutes ago, Frank DuVal said:

That's it. I would just remove the terminal from the engine side connector and solder the new wire to it rather than cutting the body harness. Those Packard 56 terminals are easy to remove and solder to. Good time to clean all the terminals in that connector. Especially the #10 red wire's terminals. They cause lots of issues. 

 

You never answered what model points replacement equipment you bought. I can find no Pertronix that sells for $250. 

Its not pertronix

its a Hot spark kit with the sensor coil cap and rotor 

[Duff71Riv]

6 minutes ago, Frank DuVal said:

That's it. I would just remove the terminal from the engine side connector and solder the new wire to it rather than cutting the body harness. Those Packard 56 terminals are easy to remove and solder to. Good time to clean all the terminals in that connector. Especially the #10 red wire's terminals. They cause lots of issues. 

 

You never answered what model points replacement equipment you bought. I can find no Pertronix that sells for $250. 

My sincerest apologies, with shipping it was $215 not $250 I went and found the bill. 
 

 

[Frank DuVal]

9 minutes ago, Duff71Riv said:

its a Hot spark kit with the sensor coil cap and rotor 

 

Did you read the instructions? Particularly the troubleshooting pages?

 

https://www.hot-spark.com/Troubleshooting.pdf

 

13.7 volts Maximum! That Delco alternator can exceed that easily under lots of conditions. The shop manual test for a good charging system is output 13.5 to 15.2 volts is normal. Sounds like you still need a resistor in the circuit. 

 

You see, I am not picking on you, I am actually trying to help fix problems. Just the old curmudgeonly way!😄

 

215, 250, close enough. Remember in Mr. Mom the 220, 221, whatever it takes.....😆

Edited March 9, 2021 by Frank DuVal (see edit history)

[mike6024]

Measure the coil primary resistance for one thing, because you don't want to use a coil with very low primary resistance unless you add a ballast resistor.
The electronic ignition I bought said just to use a Bosch blue coil, in fact they included the new coil, because it has (supposedly) built in primary resistance so that no external resistor is needed for protection against excessive current. I think primary resistance for a Bosch Blue coil is like 3 to 4 ohms.

So one point is that just using the 12V straight to the coil then the ignition, without any ballast resistor in the line, it may run fine, but maybe too much current which is not good. Depends how much primary resistance the coil has, as to whether it would be good to put in a ballast resistor.

 

 

[John348]

Isn't there supposed to be another wire on the positive side of the coil that provides 12volts to the coil while the start circuit is engaged?

Edited March 9, 2021 by John348 (see edit history)

[Frank DuVal]

Hmm, the engineers need to rethink their product. Right there in those words Mike shows "if the charging system voltage measured at the coil + is greater than 14 volts at any RPM level, the voltage regulator likely needs replacing." Then: "A maximum charging system voltage of 13.0 volts or so is plenty." 

 

I guess the designers do not fully understand lead acid battery technology! If your charging system put out a maximum of 13 volts at any RPM level, the battery would be undercharged. The system has to produce above 12.6 volts to get current to flow into the battery. A whopping 0.4 volts will not drive very much current into the lead acid battery. 13.5 volts is typically the lowest desired charging voltage for a 12 volt battery charging system. 

[Frank DuVal]

1 minute ago, John348 said:

Isn't there supposed to be another wire on the positive side of the coil that provides 12volts to the coil while the start circuit is engaged? I thought that there was 12 volt circuit to the coil and is interrupted when the ignition switch goes from the start to run position. Power is either supplied either by the "R" stud on the solenoid or the ignition switch itself?  

 

Yes, that's the dotted yellow wire in Mike's posted diagram. That diagram is for the Corvair year model where the resistance wire connects to the terminal of the engine harness/body harness connector (like the firewall connector in those front engine Chevrolets), travels halfway or so in the engine harness, then makes a U-turn and comes back out the engine harness to connect to the two terminal starter solenoid harness connector. The same terminal has a yellow wire crimped along with the resistance wire, and the yellow wire continues back through the engine harness to the + of the ignition coil. This two terminal connector is where the magic connection to the R terminal happens.

 

Some other Corvair years have the resistance wire go from the engine harness/body harness connector all the way to the + ignition coil, where also crimped to that lug is a yellow wire than travels back through the engine harness to the two terminal starter solenoid harness connector. This is what you see more often on front engine GM products.👍

 

Clear as mud?🤔 

 

I wonder why things changed from year to year/ What problem were they trying to fix? Same with the 62/3 turbo models had a ceramic resistor because "they" thought the Spyder needed more high tension voltage, but using the same ignition coil, and then all models got the same harness starting in 1964. Lots of little changes every year in vehicle production.

[mike6024]

It's funny how the Corvair ignition is the same as the '77-'79 BMW 320i, which also has points, a resistor wire (not a wire plus a resistor), and a startup bypass wire which gives you the full 12V to the coil for hotter spark at cold starts.

The resistor wires on the BMWs always go bad, car runs bad or won't run. Pain to replace the resistor wire since it is wrapped with others, so people bypass it and add one of those 1.4 ohm ballasts from a Chevy or something.

 

Nothing wrong with the resistor wire, except the cars get to 30 to 40 years old, and they fail inside, unlike a regular copper wire would.

 

[TerryB]

Every good MoPar guy kept a spare ballast resistor in the glovebox.  Many of them were the two resistor type, one for starting and one for running.  I had two in my 1964 Plymouth glovebox.  

[John348]

8 hours ago, Frank DuVal said:

 

I wonder why things changed from year to year/ What problem were they trying to fix? Same with the 62/3 turbo models had a ceramic resistor because "they" thought the Spyder needed more high tension voltage, but using the same ignition coil, and then all models got the same harness starting in 1964. Lots of little changes every year in vehicle production.

 

The same for the full size cars as well the resistor wire replaced the external resistor, long story short,  all that needs to be done is to confirm that the 12 volt wire to the coil is "good" and then locate the source to a constant 12 volt feed that comes on when the switch is turned on.

Edited March 9, 2021 by John348 (see edit history)

[Frank DuVal]

12 hours ago, mike6024 said:

a resistor wire (not a wire plus a resistor),

I've never seen a GM car with both resistors (wire and ceramic). But I haven't seen everything....😉

 

4 hours ago, TerryB said:

Every good MoPar guy kept a spare ballast resistor in the glovebox.  

 

At least up through the Aspen/Volare series. They still used the known to fail resistor with the electronic ignition module system. It acted as a fuse sort of for the the module. 🤔

 

I'm not anti electronic ignition as one might get from my comments. I am just PRO troubleshooting the problem. If the troubleshooting shows the issue is worn distributor bushing or worn pivot pin on the points plate, then Pertronix, etc. could be a solution to fix the running without fixing the real problem. I just choose to fix the real problem. I can change the distributor bushing (or put two in) and have a repair method for the points plate that is simple. A bad resistor wire can be replaced by buying a ~$120 new engine wiring harness. While this is running moneywise neck and neck with a module to run on full 12V, it has the benefit of looking better and helping cure the #10 red wire corroded terminals. Everything is a decision you can make to meet your needs. Just opinions, no right or wrong.

 

Or if one is planning to drive 200K miles in 30 years, the Pertronix, etc. can be cost effective compared to replacing points at the old recommended interval of every 12K miles! And if the right Pertronix, Crane XR-700, etc. module is purchased for a Corvair, the ballast resistor does not need to be taken out of circuit. I know of several early Pertronix modules that are still working after 30+ years. I have a Pertronix running in a Corvair I own that was installed by a previous owner. Well over 20 years ago. I see no need to remove it.😄

 

And just like if still running points, one should have a set of points and condenser (can be the old ones, as they were road tested!😉) in the glove box, people with electronic ignition should carry the above already mounted on the points plate with the small wire to the coil in the glove box. That way you will motor on without ever needing them!😁

[Buick35]

I have a 74 MGB that sometimes has a starting issue when hot.It has points. Some guy said I should change the ballast resistor,he has one on his 74 Triumph but I don't think I have one on my MG. I'm wondering if I should add one. I've changed coil,points,condenser and fuel pump. Thinking of getting a "sport coil".