changed alternator...wont crank!

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XtechX

XtechX

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Edmore, Michigan
I just changed the alternator on 68 cuda w/ a 340 ci and now the engine wont crank over. I have headlights but nothing else ??? Any ideas about what is going on....???? :banghead:
 
well im assuming you changed the alt because it wasn't charging... so the battery is probably low...
 
bad ground, loose battery terminals. i believe the harness probably grounds through the alternator at some point too...is this a nice thick painted or powdercoated alternator? make sure the block is grounded to the chassis too.
 
The reason I changed it is because the pulley fell off lastnight and I had an old alternator that I dont know if it works or not and put that one on. I charged the battery and even tried another battery that I know is good and still nothing. Both alternators are stock ones and dont have any powder coating on them. I didnt try to start it today before I changed the alternator today, wish I would have just so I knew if it would have cranked or not. It had been on the battery charger all night because the battery ran down after the pulley fell off last night, I dont know if that is a worthy clue or not? Also it has a painless wiring harness in it that i didnt install so I cant make heads or tails of it as far as fuses go. I can get the engine to turn if I jumper the solonoid but not with the starter button (no key) just toggles and a button.
 
odd, maybe the starter solenoid got fried if you accidently arched wires while swapping out alt or just went bad?

also, if they used the massive painless fuse block that goes between battery/alt check that fuse, it would be a big piece of plastic with inline between the two, most dont use it but some do, if it has one it'll be obvious to spot.

Does car RUN if you turn ign. to run position then jump starter sol. to get her to start? Just trying to rule out other wires.

Could also be corroded wires on battery or starter post.
 
i remember having a similar issue on mine a few times. with me i changed the NSS for no reason because it came down to having a battery with too small of posts. i doubt you hurt the starter solenoid because i can't count the times i have jumped mine with a screwdriver from the engine bay to mess with the carb...but it would be a good idea to see if you can make the car actually run by having the ignition on and jumping the starter. i know you said you just have a button..but obviously u have a kill switch somewhere, make sure that wiring is ok, and like i said before, my harness grounds through the alternator. i know this because my horn stops working if my alternator is unhooked. then works just fine when everythings hooked up. the starter system is pretty simple...a constant hot, and a key/switch activation 12V which kicks on the starter. if you already bypassed that with a button, even your NSS is no longer inline. so it has to be juice/battery related.
 
Does the car still have a fuseable link? If it does, it sounds like that is bad. The headlights might be wired separately on a circuit breaker and that's probably why they work.
 
Since we don't know how this thing is wired, we are just "talkin."

But get your test lamp. Should have power on both sides of the starter button with button pushed

Should have power on one or other of the "push on" terminals of the starter relay.

IDENTIFY which "push on" terminal of the starter relay is getting power, if it is, with the button depressed, and GROUND the other terminal. It should crank. If not, bad starter relay. If it does, problems in the NSS circuit.
 
Agree with 273. The alternator has nothing to with starting the car. If you have a fully charged battery, the car should turn over and run for several hours without the alternator connected. I assume you disconnected BATT- before removing the ALT, because if the ALT output wire touched ground, your battery could become a welder. First thing is see if your battery holds 12 V while trying to crank. Requires a multimeter ($6 or free).
 
Thanks for your help guys...I got it, it was a blown fuse under the dash. It was the fuse for my push button ignition.
 
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