63splitter

Hi everyone:

1960 corvette (I always forget to put down the year, so I thought I would say that first).

I have a points-style distributor and was doing some wiring on my restoration. Like a good mechanic, I took the positive cable off the battery before I did some connections. I put the cable back on, turned the key to the on position, and within 30 seconds a whiff of smoke came from the ballast resistor. I quickly turned the key off and it stopped smoking.

I hear you should NEVER leave the key in the on position without the car running if you have a points system. I understand I could have blown up the coil too.

Is all this true? Can I really burn up the car if I turn the key to the on position and leave it there while I check some electrical things? I don't have an accessory position on the ignition switch, so what else can I do? Would switching to an HEI distributor correct this? And if so, would I still need the ballast resistor?

Thanks for the help,

Rick - Erie, PA

Frankie the Fink

OK - first off...put a battery disconnect on the car for your own piece of mind and to keep from having to work the cable on and off every time you are doing electrical work or storing the car or have an ELECTRICAL EMERGENCY. Second, yes you can do damage to the ignition coil if you leave the car in the ON position for an extended period that is just life with these old cars. Some newer ignitions provide some protection for this (like the Pertronix Ignitor III)...while also eliminating the ballast resistor.

I have left the key in the ON position for a minute or two while checking a component and its never hurt anything. You can make a fused jumper lead that you run off the battery to the power lead of any piece you are trying to check out...you could also pull the ignition lead off the ballast resistor when checking things like the radio. (This is basically what modern ACC positions do on the ignition switch).

None of which explains your smoke -- you may have just been unfortunate enough to have stopped the car with the points closed and therefore current was running while you had the key in the ON position. If the car still starts and runs all right you are probably OK.

63splitter

Thanks - I'm pretty worried about this, so I think I will look a the Pertronics Ignitor III and their coil, getting rid of the ballast resistor. I'm sure when I had shut the car off the last time, the points were probably closed, so when I turned the key on, it must have been sending voltage to the coil.

Thanks again for the reply and the education.

Rick

69427

I'm having a bit of a problem accepting that leaving the key on is a big issue. It's a common experience that older cars are going to experience a stalled engine on occasion, and without an Accessory position in the ignition switch everyone knows that someone is going to have the ignition on to listen to the radio while he's washing/waxing/working on the car (or parking with his girlfriend). I can't believe Chevrolet would design/build a car that had potential burndown issues if the ignition was on (with the points closed). (I sold my '61 years ago, otherwise I'd go make some electrical measurements.)
Something else must be amiss here. (Is there a short from the ballast/C+ terminal to ground in your wiring somewhere?)

midyearvette

if you leave the key in the on position with closed points, you can smoke the br in a matter of time, also some new br's will smoke initially
the coil is fine and so is the br if it starts and drives ok, although you could test the br if you are worried
it seems to be attractive to convert these old systems for the ease of maintenance, no points or br, but the old way is basic, simple and fool proof and lots of folks like to change points once in a while too...jmo....

Frankie the Fink

Points are certainly not fool proof.

There was an instance on here about a year ago where a mechanic installing an after market radio in a member's C1 ( a lady forum member IIRC ) left the key in the ON position for a length of time while testing the radio and fried her ignition coil.

I know of no reason why an older engine should "stall on occasion" if properly maintained. Yes, you can leave the key in ON with older cars and listen to the radio or park with your girlfriend -- and sooner or later you will get to walk to your next destination.

MikeM

For those that like to listen to their radio, without the engine running and with no accessory position on the key switch, owners used to just wire the radio straight to a hot wire in the fuse box and bypass the ignition switch.

If you want to work on the electrical system and the key must be on, just pull the 12v wire off the coil until you're done.

There's no need to make a bigger event out of this than the small issue it is.

Chuck Gongloff

Did you paint/clear coat the ballast resistor to make it all purty?

If so, you could have just "smoked" the paint off of it.

I wouldn't worry about it. That being said, it's a known fact that with points style ignitions, you should not leave the key in the ON position for extended periods of time.

I've driven/owned these cars for decades, and never gave the ballast resistor a second thought.

Chuck

Frankie the Fink

Likewise. Which makes it interesting that there are two currently running posts on ballast resistors ?!

I think they are devices left behind by ancient aliens and were first used at Stonehenge....but then I wear a tinfoil hat on clear days...

FTF

69427

You've spent too much time in Florida. I grew up up north (midwest and Alaska), and in the winter it wasn't uncommon for the engine to stall while warming up. We often would start the car, and then go back in the house while it warmed up. Sometimes it would just load up and stall. Carburetors weren't perfect back then. Despite that, and leaving the key on to listen to the radio as a naive youth, I never heard of anyone having ballast resistor problems.
Apparently we've had different experiences in life. As I mentioned earlier, I would be incredibly disappointed if the power dissipation calculations weren't made (and followed) by the design engineers prior to these parts being manufactured. (Full disclosure: I have no first hand knowledge whether or not they did, though.)

Chuck Gongloff

I didn't want to mention anything about your tinfoil hat, but since you brought it up, I think it's more like a "beanie" or a yarmulke.

It fits nicely under your ten gallon cowboy hat.

Chuck

69427

I'm seeing a bit of conflict in statements, here.


Guys, I don't have any skin in the ballast resistor game (so it doesn't affect me either way), but I'd sure like to see some warranty numbers or power dissipation numbers to put some confidence in some of the statements made here. Hundreds of millions of vehicles were equipped with ballast resistors, and the topic (ballast failure) rarely comes up in conversation.

MikeM

I don't see any conflict. Just don't leave the key on without the engine running and you won't have trouble with burning your points and/or your resistor for many, many miles/years . And, that takes away the excuse to put some kind of electronic trigger that costs a lot of money.

Like you though, I've driven many years with that resistor in place. I've seen them hot when I left the key on and I've seen them not so hot. I've NEVER had one fail.

I don't know why the resistors get so much play here as trouble with them is practically non-existent in my experience(s).

midyearvette

.....
the lowly br, is blamed for a lot of woes and all it is trying to do is it's job the way intended
all it is is a cheap part, easily replaceable and meant to give longer life to the coil and points
i made the statement "foolproof" because of the simplicity of the design and ease of diagnostics
and if that bomb is ever dropped for emp, the lowley br and it's system will keep on truckin', (maybe)unless something more sophisticated comes along, then we just go in the buggy whip business......

Frankie the Fink

Having been my Dad's "uncompensated" car mechanic on his used car lot in the '60s I
can say I've seen a few ballast resistors (and fusible links serving the same purpose) literally "go up in smoke". Not tons of them but enough to know it is indeed a failure item.

I suspect our precious classic cars aren't driven nearly as far and hard as "back in the day" so failures are less prevalent.

John McGraw

It has been my experience that the coil will swell up like a poisoned pup, and the points will burn to a crisp long before you damage the BR. The wire that the BR uses is nichrome, the same wire they use in electric heaters! The BR will glow red hot and still not usually fail. That is why they are cased in ceramic. Early, original Corvette resistors also had a ceramic back that was held in place by the clamp to keep the heat from setting the fiberglass of the firewall on fire. Later resistors were twice the resistance, so the heat was not as intense.

I left an ignition switch on my 60 in the trailer on a cross-country trip to nationals several years ago, and when I go there, the points had melted the nylon rub block to a unrecognizable lump, the battery was dead, and the coil had gotten so hot that the bottom bulged out, but the original 1960 resistor was fine. Charged the battery and put a new set of points in it and it was fine.
Original C1 BR's had a resistance of only .6 ohms, so they ran hotter than hell. Later C2 resistors were 1.8 ohms, so they ran much cooler. The point life on original C1 resistors was much lower as well since the load acrosss the points was much greater. All of the resistors being sold today are the 1.8 ohm resistors and most of the original .6 ohm resistors have fallen by the wayside. A lot of people in the day, replaced the resistor with the later model one to extend point life.


Regards, John McGraw

larrywalk

The ballast resistor supplies additional resistance into the ignition circuit to limit the current to about 5 amps with the points closed. If the coil had been replaced with a performance coil having a primary resistance of a lesser amount than the stock coil, the current in the primary ignition circuit will be higher than normal.

Since the heat generated by the current in a resistor is current squared times the resistance, a higher current will increase the heating of the ballast resistor significantly! Perhaps you ought to measure the current in the primary circuit? If it's greater than 5 amps, get a different ballast resistor or use a stock coil.

KC John

I haven't done this myself, but I thought I would mention it. Some guys that are much smarter than I when it comes to electronics use a battery charger rather than their battery when doing their wiring.

I think it has something to do with providing enough volts to work a circuit, but at less amps so as not to fry the wires. That's just a guess, like I said I'm not too good with understanding the ins and outs of electricity.

Frankie the Fink

Yes! "Electricity simply doesn't know how to conduct itself!".

In some instances the ceramic on said resistors is cracked during "aggressive" installation or other abuse causing early failure.
I can tell you that I knew of folks years ago that always carried a spare B/R as part of their roadside emergency kit. That should tell you something...

MikeM

Psssssssst! Let you in on a little something else! Most people I know did not/do not carry a roadside emergency kit!



Back then, women wore bobby pins in their hair. Ever think of jumping a burnt resistor with a bobby pin?