QuestionI'm workin on a 55 fairlane with a V8 y block motor with an alternator. I can't figure out why I'm not getting spark at the points. I have a new coil, 12 volts at resistor, 6.9 volts after resistor. New plugs and s.p. wires. Installed new condenser and points set with .016 gap. It's been a while since I've set points but I'm sure I did it right. I thought it might be ground wire problem in the distributor. so I made a new wire to bypass it. Didn't help. I did this cause I noticed the first time I took of the dist. cap and had the motor spun over I could see a very small spark underneath the points plate. But I have not seen it since then.
This is a friends car that he just aquired. I noticed the wires to the coil were hooked up reverse of what I think is normal. Power WAS going to the negative side of coil and distributor/ground wire going to the posive side of coil. I have reversed it since. Or is this way it supposed to be stock on this car stock? I suppose I would know this if my friend would get the shop manual. I'm baffled. Maybe I need to add a ground strap from body to motor.
Your help would be greatly appreciated
AnswerThomas,
Looking for spark at the points will not likely tell you much. I would use a timing light to check for spark while cranking with everything put together normally, or pull a plug and with the wire connected touch the threads to ground while cranking looking for spark to jump the gap.
Otherwise, sounds like you have correctly reconnected the coil. Battery power via the resistors should be on the positive contact of the coil at all times; it's the negative side that is switched ON and OFF by the points. You can test the coil for spark:
- Disconnect the coil high tension wire at the distributor, leaving it dangle from the coil.
- Disconnect the coil negative wire and connect a temporary jumper wire instead.
- With the ignition ON, touch the other end of the jumper to GROUND for a moment. This charges the coil.
- Touch the high tension wire from the coil to any ground and look for the spark to jump. Be careful not to shock yourself.
If this test is good, then the problem must be in the distributor. You should test for continuity between the points mounting screw and GROUND with a multimeter. Then test the points moving contact back to the distributor negative terminal as well. Also with the points OPEN, there should NOT be continuity between the coil negative terminal and ground.
Rick
