All Charged Up

This is mostly an inquiry of a "what was it" scenario. Beginning at the end, my Duster needed a new battery. I was trying to get the car to start on the now replaced (agm style) battery and used a "jump start" feature from a charger since it wouldn't fire on its own. The car fires and everything seems normal until I try to start on it's own again and won't turn over. New (standard style) battery goes in. Turns over great but now won't start! Okay, getting fuel, check. Getting spark, no. Start diagnosing the MSD box and get that problem resolved. (Maybe went in to a safe/protect mode due to the jump box?) So here's the question: I am in the engine bay checking voltages and out of curiosity I check voltage at the charging post on the alternator. (It's a tuff stuff one wire.) Real quick: the battery is in the trunk and has a master disconnect. I have the elec. fuel pump off at this moment also. The cars ignition is in the run position while checking voltage. As soon as I touched the voltmeter lead to the charging post the starter motor engaged and bumped the engine over. I understand the charge cable and starter cable tie directly to the battery so I see how it can happen. But did the alt. somehow retain some kind of charge or perhaps re-magnetize the field? Needless to say the car and everything running just fine but was really curious as to why the checking of voltage at the alternator caused the starter to bump. Have a great weekend everyone!

You grounded the battery and sent that charge to the starter. (your alt and battery are connected)
Something isn't wired correctly though. Your ignition has IGN1/IGN2, you should only be sending a charge to the starter with IGN2. If you had it in the "run" position (IGN1) and it charged the starter then its wired backwards. That's also why it's not starting. IGN1 needs constant 12V, IGN2 only gets 12V when cranking.
Good luck!

There is absolutely no rational explanation as to why connecting a meter to the alternator could bump the engine.

You have a wiring problem, or something just happened to move and short, etc at the time.

Did you have either probe of the multimeter anywhere near any of the starter / relay wiring?

67Dart273 said:

There is absolutely no rational explanation as to why connecting a meter to the alternator could bump the engine.

You have a wiring problem, or something just happened to move and short, etc at the time.

Did you have either probe of the multimeter anywhere near any of the starter / relay wiring?

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Thank you for replying. Everything is honestly normal with the wiring as it runs and performs fine. I’ve checked everything multiple times and it all checks out. Perhaps it was just a very coincidental incident. The relay is isn’t in the engine bay so I was nowhere near it. I guess I was wondering if this ever happened to someone. Thanks as always for replying. Everyone’s help and input is always appreciated, thank you.