Burning Points

2

25 TA

Junior Member
Recent full engine overhaul running great untill 9/18/11, started burning points. I have 6 volt, positive ground, starts within 1/2 turn when points not burned. Generator is putting out 6.4 volts idle or when reved. This morning I was at 6.4 volts, reved engine and charging whent to 8.11. After we used emeroy cloth on points and installed a new 6 volt coil, charging is constant at 6.4 to 6.5 volts, with lights turned on, voltage drobs to 6.3. I have modern distributor using 1959 to 1974 ford standard points.
Any and all help why I am burning points, or what to look at will help and be appreciated

Thank you
25 TA
 
Loose connection somewhere between cut out and battery, causing voltage to go beserk and burn points. Check connections at: cut out, junction box, ammeter, added fuse holder, (if any)
Remove both forward 3/8" nuts on junction block and tighten both of the 3/8" nuts inside the box.
Be sure ground system is good by clipping test light to gearshift, put point to middle of + battery post, step on starter with key off. No light=good grounding. Light on=poor ground connection somewhere.
 
Last edited:
I agree with Bill. If you don't have a regulated generator, then any poor connection in the charging circuit can cause the voltage to go very high and burn the points. If you turn on the lights, then they can also burn out from the high voltage.
 
I was taught the following 'trick' back when ALL cars had points type ignitions.....Be sure to clean the contacts with some sort of fast drying solvent before installing or cranking. Also be sure that the distributor cam is not overly lubed. Oil/grease, if left on the contact faces, will burn causing erosion,sticking, and shortened service life.
 
The condenser is not being seen across the points, check the mechanical connections at both ends. If everything has fresh paint from the overhaul it maybe insulating the condenser from a good ground.

Just something to check.
 
I agree with a few others in regards to the condenser. The job of the condenser is to take the brunt of power from the coil when the points break to keep the points from sparking / burning.

In modern times in every other application other than automotive we call them capacitors. :)
 
What color are the points? if the points are blue the cause is usually excessive heating caused by improper alignment, high resistance or an open condenser circuit.
 
RonC said:
What color are the points? if the points are blue the cause is usually excessive heating caused by improper alignment, high resistance or an open condenser circuit.
Click to expand...
But remember, he said he was charging well OVER 8 volts, which is probably toasting the points.
 
BILL WILLIAMSON said:
But remember, he said he was charging well OVER 8 volts, which is probably toasting the points.
Click to expand...
The points in good condition, don't know the difference in 6 volts or 12 or anything between. Voltage is absorbed by the condenser to protect the points when they are grounded (closed) and releases a spark or jolt of electricity at the point of opening to the coil primary winding. This creates a much stronger jolt at the high tension wire through the secondary windings to the top of the dist and then to each spark plug individually.

I also think a bad or failing condenser.
 
With all due respect you don't need a ballast resistor on a 6 volt system so its a moot point. This thinking would only apply to a 12 volt system where you suspect you have a 6 volt coil.
 
I was told that you never use emery or sand paper to clean points, that what point files are for. The emery and sand paper leave particles behind the cause the points to burn out early.

I was also told that it was a good idea to clean the points, after filing, by polishing them using a hard polished cardboard like a matchbook cover.

Just My W.A.G. at the problem
JB
 
The charging system putting out 8 volts or more is too much and that problem should be fixed.

Also make sure the points gap is .020" so the points aren't closed for too long a time, or too short a time.

I too suspect the capacitor may be bad. Buy a good heat proof new one, and it wouldn't hurt to buy a spare to keep under the seat.
 
Hoop,


While I may be mistaken regarding the ballast resistor the last thing I need to do is google Ohms law thank you.

If Ford used ballast resistors on later 6 volt systems I would assume it would be to allow a hotter spark during starting during which the resistor would be bypassed.
 
Last edited:
With the points closed, engine off, and key on, my slant pole coil draws 4 amps on 6 volts. As Hoop said this should be checked, and if your dash guage isn't accurate, the you could connect an amp meter across the fuse contacts with the fuse pulled, if you happen to have a fuse. If you don't have a fuse, just connect an amp meter to ground and the coil primary that goes to the points, but leave the key OFF. Remember, the coil is always "hot", so the amp meter will complete the circuit to ground.

If you get a reading over 4 amps, I'd try another known good 6 volt coil. If the coil reads 3 to 4 amps, then I'd replace the capacitor and see if that doesn't fix the burning of the points.

BTW, while the engine is running, the coil draw drops to about 1 to 1 1/2 amps.
 
I would like to recommend using caution when checking a coil with an ohm meter. Just as it burns points it can give you a pretty good hit when you disconnect the meter.

Whenever I check any kind of inductor with an ohm meter I take care not to touch the leads. I've been hit too many times :mad: mostly by audio output transformers on older audio amplifiers.
 
You stated you were using the new 'modern' upper plate, so its easy to just change the condenser.. The capacity should be in the .2-.3 mircofarad [sp] range.. Some old cars will run with a bad condenser,but, if a 'modern' one fails the car won't start.. It easy to get lousy parts today so just make sure you're buying a good one.. I think Echlin at NAPA is about the best today, you're more apt to get a decent one there..
As the boys said, high voltage as in a runaway generator will fry points in a hurry.. Points can only take 8-9 volts before they start complaining.. I think you mentioned having problems after changing the coil, that may be a good thing to look at also..
 
You must log in or register to reply here.
Back
Top