No spark

[DrewJ67]

I've looked through several posts in this section and I'm sure this has been asked a gazillion times. I have a 67 barracuda with a 273 2bbl. It has the original 1966 alternator which has just been rebuilt. The car has set for over 5 years without running. I've got the fuel system all ready to fire up but I'm not getting spark. I have a good/new battery.The car turns over fine I'm just not getting spark. Cap and rotor look good, as do the points purely from a visual stand point. I'm getting 12.5 volts to solinoid, 10.5 to each side of ballast when key is in run and 10.5 on positive of coil. When key is in run the voltage regulator starts to smoke. In some of the other threads it sounded like they did not make that style of regulater anymore. It's single point original distributer. If they dont, can I make my original alternator work with a newer one. Please excuse my ignorance on this I'm just trying to get this old girl running again.

 

[KitCarlson]

It is not possible to test for "good" points by inspection. You can inspect for "bad", like broke spring, corroded contacts, or not opening or closing. Point closure can be tested for a good connection by quickly the voltage at the coil (-) with key on, and points closed. The voltage should only measure a few tenths of a volt. The other thing to test is the point gap with points fully open, about 0.017" with very clean feeler gauge.

The 10.5V measured at coil (+) indicates points are likely open, but the voltage then should be near the 12.5V measured at solenoid. The 10.5V indicates there may be drop, at bulkhead connections, or significant load in ignition supply. Since the early style regulator is smoking, and the alternator has been rebuilt, it is possible the field connection to the alternator is shorted to ground, or a short in field.
It is also possible one of the resistors on the mechanical regulator is contaminated with dust, and burning off. Still, the 2V drop is too much, but may not completely keep the ignition from working. There might be two problems.

A quick test may be to pull the connections off the regulator. Then crank then crank and see if the voltage at coil (-) is bouncing like is should, be as points ground and open. Then test the ballast and see what the voltage is doing there on both terminals both terminals, with points closed. One should show higher and close to 12.5V, if it is low that would indicate poor bulkhead connection or other supply problem.

 

[AJ/FormS]

For sure disconnect the regulator for now.
The point contacts can become oxidated when left open for long periods of time. This can prevent them from working. The coating can be cleaned off. It may not be visible.A failed condenser will prevent spark as well.

 

[BillGrissom]

Yes, you can get a new electronic Vreg w/ same connectors as the original mechanical one. I bought several on rockauto for $11, but recall ~$20 now. They are thin chrome. Others look like your original black box.

Test the coil alone first. Ground coil- (removed from distributor wire) quickly and remove. You should get a spark from coil+ to gnd each time you lift the coil- wire. It should be able to throw a spark 1/2" in air. That is all the points do, so work your way forward.

At some point, you will decide to stop fooling with points and move to electronic, like most here, and let it manage dwell and kick up the spark. The 8-pin GM HEI module is easiest (85-95 trucks/93 cars). TrailBeast here sells the parts, but also need a slant e-distributor (1971+).

 

[DrewJ67]

I finally got back to working on it today. I put a new ballast resistor on it and BINGO I now have spark. They had to order my voltage regulator. I appreciate the responses. This site has so much valuable info and knowledge.