HI guys, working on our 318 because the lights/accessories all of a sudden died....tested the alternator and it failed, replaced the brushes and put the alternator back in and now it wont start!! How is the ignition system and the charging system related?? I never disconnected the battery before removing the alternator but i am sure nothing arced during the proccess....any tips?

what means dont start? turn over or run? i believe the igition wire that feeds the VR goes straight to the alt field. short that out and it might not start....

hmmmm...
ya it turns over but no ignition

need to find what went open that killed the lights etc. I'd see if you have fire at the fusible link then the bulkhead then the ammeter terminals for a start. EDIT I missed the 1st 2 posts while I was posting. Disregard my post.

look at this schematic.
http://www.mymopar.com/downloads/1970/70ChallengerA.JPG

disconnect the blue field wire from the alt and try it. but if that was shorted, youd probably melt something

with a test light or VOM see if you have fire at the coil positive terminal when the key is "on" and when it is in "start". If not trace it back to the ign sw & see where the "open" is. Also check that the ECU has fire when "on" and "start"

ya i have approx 6volts on the + coil terminal...which sounds right to me....agree?