The 500 in my 76 chevy pickup quit running the other day. It started running really rough and bogging down and then it died. It is not getting any spark at all. I checked the coil and it is still getting power to the positve terminal and the terminal going to the points still has power. I checked it with the starter cranking too. I replaced the coil, points, and condenser but it is still not getting any spark at all. The distributor is still turning and the points are opening and closing. I also replaced the wire from the coil to the points in case that was bad. Its not the wire coming off the distributor. The coil does not put out any spark at all. Anybody have any idea what could be the problem?
Did you replace the condenser? Maybe the condenser is bad. I always replaced the condenser along with the contact points. A condenser that looses capacity will make a very weak spark, which is sort of yellow as opposed to a blue color.
Open the points by jogging the engine with the starter, and poke a screwdriver across the point arms. You should get a spark from the screwdriver as it shorts the points. You could also dis-connect the negative wire from the coil and short that terminal to ground a see if the coil itself will make a small spark (small because the condenser is in the distributor)
With the coil hi-tension wire removed from the dist cap, the end of that wire should have a hot spark if it's held near a ground, when the points open, or by shorting with a screwdriver. Be careful when doing this!!
Hope this helps find the problem.