Need ignition help

My 77B was running great and then quit. It has a 25D distributor in it.
No spark in either the distr or coil. Changed points,plugs,cond,coil,starter
and ign relays. Checked plug wires and other ign wires.
I get about 11 1/2 volts from the starter when cranking going to the coil
The white /light green wire,,,,,with the resistor wire,,,,shows 12 1/2 volts UNTIL it is attached to the coil then drops to 6 1/2 volts when attached to coil. Is this correct ?
Any ideas to get me going in the right direction ? Thanks

have you tried switching the wires that attatch to the coil.. ie, polarity?

Ken, look into upgrading the dist to the 45 D then put a petronics unit in it along with a pertonics sport coil (matched voltage, etc), If it ran great and then quit suddenly....ingition is usually the culprit... all your work has made sure what was NOT broke...hook up the up dated dist and away you go.

Happy Trails

how many miles on the old one?

have you tried to start it..... ????

Jerry,thanks for your input. I do have a new[factory rebuilt] 25D on the way.
I looked at going with a 45D but saw something that sounded like it would not be compatable.
This old distributor, the 25D, was used from 67 to 74 and the car is a 77 so
I have no idea how many miles are on it. It was on the car when I bought it a few years ago.

there u go.

Hi Evan, thanks. Can the wires at the coil be switched without causing
problems somewhere else ?

yes, many times but not with the switched wires at the coil

yeah pretty much. i forget the setup but it's hooked up according to what ground you have in other words if you have a positive ground car i believe they are reversered therefore the other side heading to distributor however from what i know the coil can be ran in either reverse or direct setup although i do believe there is an optimum polarity.