burning points immediately (SBC)... why?

My daily is a '63 nova with a '67 283 in it. I replaced the rotor, cap, condenser, and points. It still had a sporadic miss, so I replaced the plugs and wires. No change. I then replaced the coil. I took it for a test drive and it seemed ok.
The next morning it ran ok in park, but under load would stumble and hesitate. I discovered the wire to the + on the coil was hot then discovered the last foot was a piece of smaller wire that had been crimped on. I replaced it with a larger piece. No change. I pulled the new points and discovered they were burnt and slightly melted. I put the old points back on and test drove it to find it ran fine. The next morning it would barely run in the driveway.
I pulled the points and they were burned too. I tested the new coil and it has pretty similar resistance to the old. I'm not running an external ballast resistor, but I never have in the 6 tears it's been my daily driver. There is no current runing to the coil when the ignition is off.
Any ideas on why my points are burning out so suddenly?

 

Did you put in a 6 volt coil?
Inductive resistance of a coil will not read on a meter.
All a meter will tell you is that the coil is not open, or burnt out.

 

That last foot of wire may have been a resistance wire, and now your putting full voltage to it . Check that and if it is , put it back or put in a ballast resister.

 

Hi find a wiring diagram and look for a resistor wire or a resistor block if these are shown replace them...also change the condenser even if you just bought it....I had a NEW BAD one and it did about what your saying........Miller

 

The new coil is 12 volt. I don't think the last bit of wire was intentionally a resistance wire, but I do believe it was restricting the flow. However it was dangerously hot and had melted the plastic loom it was encased in, so it had to be replaced.
The fact that the first set of points burned before I replaced the wire, leads me to believe something else is causing my points to burn.

 

Yes that piece of wire is the ballast resistor on other makes and models. Like all resistors they get warm while reducing the voltage to the points. If you can't put that specific piece of wire back in, put a ballast resistor for a Mopar in that wire to the coil. That will knock down the voltage to the points so that they will last.

 

I suspected the condenser too, so i replaced the new one after the first set of points burned. I even upgraded to a better one. They still burned. I know it is possible to get two bad condensers, but I'm looking at other possibilities first.
As far as a wiring diagram, the car was originally a straight six so it wouldn't apply specifically to my set up.

 

Yes, you need that resistance to reduce the voltage to the coil so you won't burn the points. You should have around 9 volts to the coil with the key on. 12 or so when you are cranking and the resistor bypass off the starter is working.

As Tommy mentioned, if you did remove the resistor wire you can hood up an inline resistor. There are several styles and they are not very expesive. They do get extremely hot.

 

Best bet is to install a ballast resistor between the plus 12 Volts and coil. I believe that a stock Chevy resistor is 2.4 ohms. The FOGGER

 

Is it safe to just splice a smaller bit of wire before the coil as a reducer? I thought ballast wires were run all the way to the ignition to the on position, while a seperate wire to the start position allowed more juice?

 

Make sure the points plate ground wire is still good.

 

check voltage to coil as said above also check charging voltage.

 

Ground wire is still good. I'm going to go get a resister. It's getting 12 volts to the coil at run. I'm still not 100% convinced since the first set of points burnt up before I changed the wire but I hope that's all I need.

 

On the chevys with points, the resister wire normally runs from the fuse box connection on the engine side of the firewall all the way to the coil. Sometimes it is looped back in the harness since it takes a certain lenght of this wire to reduce the voltage to the required level. It is a steel wire not copper and in encased in a white cloth looking insulation. If this wire is shortened any at all it will get hotter than normal and supply more volts to the coil that is needed. Also there is a chance that it may have gotten hot enough in the past to burn the insulation off where it loops back on itself some where along the way. This short circuit will do the same thing as shortening the wire.

 

NO, a smaller piece of wire will get really hot really fast. Do what others have said with a Mopar resistor.

 

The wiring for the original 6 will be the same as what you need for your v8 clear to the dizzy.

 

A very way out there idea: wire coming from the bypass terminal on the starter solenoid to the coil. If the solenoid was partially defective it might keep the 12V on the coil. This wire should only have the 12V when cranking the engine and then the coil gets its voltage through the ballast resistor or wire.

Condenser can do this, and I too have bought new ones only to find out that it was bad.

 

You lost me d2.
When I check the wire disconnected from the coil, it reads 12.46v.
When connected to the coil, it reads 11.3 volts.
I bought a resister that reads 2.2 ohms of resistance. When I run the wire to the resister and check the voltage at other side I get no drop at all.
When I run the wire to the resister, then to the coil, I get 5.8v at the coil. Does that make sense?
Well anyways, I figured 5.8v was too low of voltage, so I didn't mount it and test it. I'll need to return it tomorrow and exchange it for a lower drop resister.

 

It has to be a bad resister

 

5 bucks at Rockauto

Just get an IGNITION ballast resistor at any auto parts store. That is their only purpose...to reduce the voltage to the coil while it's running so that the points will last. They have a heat sink. They are sized right for their only purpose. You cut your factory one out of the circuit. If you try to jury rig it with a resistor not made for this purpose you will never know if it's correct or not.

You might have needed a condenser. They are there to make the points last longer also but until you get an ignition ballast resistor it the circuit it will just eat points.

 

I think your problem is condensor which prevents arcing at the points. Over the years I've several times jumper wired past a burned out resistor and ran an extended time, tractors and automotive. The original reason for using a resistor was to increase points life, but I found they would still run perhaps several thousand miles with the resistor bypassed.

 

Tommy, there's an old farmer's tale about leading a horse to water. Good to see you yesterday, MR. Asshole.

 

You don't have to be so formal. 60% of my family has hemroids but I'm just a plain asshole.

Yes it was great day talking to everyone.

 

You shouldn't be getting a full volt of drop with the engine off unless your battery is kinda old or there's shaky battery cables. I wouldn't worry about the 11.3V right now and just run that resistor.

Yes, until you place a load (the coil) on the resistor, it won't cut output voltage.

I'd run that resistor, with a weak battery or cable your voltage readings are suspect. Like the others have mentioned, add the auxiliary wire (if it's not already there) from the starter to deliver 12V during cranking only. You'll be rewarded with quick starts and long lasting points.

PS- if it were mine and burned one more set of points I'd be looking to ditch the points& resistor for a breakerless/electronic trigger setup. But that's a whole nother post.

Condensors are cheap. Throw one at it.

Good luck

 

Did you leave the key on?

 

Hide an MSD 6AL ignition box inside the car and keep it stock looking outside. YOu wont burn your points again should take an hour or less to install. Or get the $5 resistor from the parts store, and an extra one or two and an extra one or two sets of pints and condensers to keep in the tool box or glove box, BC we all know they go bad when you least expect it.

 

Everything you have done so far is correct. But the resistor value is way to high, so you need a 2 ohm or so resistor to drop the voltage at the coil to 6-8 volts.

My way out idea was the wire coming from the starter solenoid that is going to the +coil (along with the wire from ballast resistor or ballast wire). If you don't have the other wire I mentioned, then just concentrate on the ballast resistor value to get the 6-8 volts. But if you do have two wires at the + coil, then if the starter solenoid has a defect that allows +12V to the solenoid terminal with the wire going to the +coil, then it might be possible for +12V to always be at the coil.

Probably just disregard the way out idea, since you have 5 or so volts at the coil and that pretty well rules out the way out idea.

 

get a pertronix setup,cheap,easy and dependable plus no more points headaches.

 

I exchanged the 2.2 resistor for one that's reading about 1.1 ohms. When I hook it up it starts at about 8v and starts droping pretty quickly. Shouldn't it have a consistent number? As it gets down to the low 6's and high 5v's it starts to smoke and I disconnect it.
I know it is a resistor and should get warm, but should it get real hot to the touch? The first one I bought got real hot and smoked as well. I don't want to throw the new points in and start it if I've got a fire hazard goin' on with the wiring and resistor.

 

Are you using an automotive ignition resistor? If not, get one. If your using a Radio Shack, or similar, they are rated by Ohms and current capacity. sounds like you are using an underrated (current) unit.