No spark and i can only get 5V at the coil.

YoungDart75 said
Well after this im going to be trickle charging the battery tonight and then having it load tested tomorrow first thing.
All the below voltages were taken while turning the motor over attempting to start it. This was immediately after the battery read 12.1V with key off and not under load.
Battery power = 8.4V
Power to coil + = 7.2V
Power from negative coil to ground = 1.8V
Power to ignition(red wire) = 8.4V
Power from ignition(brown wire) = 7.7v
Ecu case voltage(case to ground)= 1.5 millivolts

The reason im load testing the battery tomorrow is because the damn thing isnt sending enough damn power through the systemin the first place during the starting process. So i cant expect any of my other readings to be proper without getting what they need. This would also explain why the 12v jumper wire to the coil didnt work either, because it was never 12v. Will update again tomorrow morning. Also nm9 ill check ur test after i find out about this battery. Thanks for all the help so far guys. Greatly appreciate it.

Did you read the link in put in POST NUMBER 3?:banghead:
Looks like your problem at this point is ........drum roll.....weak battery.
At least part of it. Things stack up on these old cars.

Now on my "problem", if it matters.
What I do is pull the yellow wire off the start relay and just check voltage at "run" at the ballast.
Or go upstream to other points I can get to and make an educated guess.
For example I had 12 volts at the car side of the column connector. So that ruled out everything back to the bulk head disconnect.
After reseating my steering column connector and a little cleaning on the bulkhead (damned Packard blade connectors) I've now got over 11 volts at the ballast.
Of course the starter isn't engaging when I do that. But my car starts fine with a new battery.