Dodge Dynasty charging system trouble

Measure the voltage on the two small terminals on the back of the alternator while the engine is running. Then we'll know where to go next.

Dandy. I always second guess myself but if you truly have no voltage there, this is going to be a quick fix. By the way, you DID have the engine running when you took the readings, right? There is supposed to be 0 volts on both terminals when the engine is not rotating, (cranking or running).

The ignition coil, injectors, oxygen sensor heaters, fuel pump relay, and alternator field are all powered from the automatic shutdown (ASD) relay. The fact the engine runs means all of those things are working, except the alternator. That only leaves the piece of wire from the splice to the alternator.

I only have a '92 service manual but the circuit should be the same. Look for a black ten-pin connector behind the battery. There will be a dark green / orange wire in one of the corners. Back-probe those terminals to see if voltage is there on both sides. The splice for all the other stuff is before that connector, so if there's a bad connection there, it will only affect the alternator.

Look for that connector and see if there is voltage on either or both sides of it.

If you have 12 volts on both sides of the connector but not on either terminal on the alternator, there is a break in that wire between the two. There should be no splices to corrode in the harness. Look near the black plastic terminal block on the alternator where the wires come into it to see if someone poked a hole through the insulation to take a reading. I forbade my students from doing that because moisture will get in there and corrode the wire.

If by "anywhere" you mean including at the connector, there has to be a break in the dark green / orange wire before the connector. You can prove that by using a jumper wire from the battery positive post and a paper clip stuck in beside the terminal in the connector to apply battery voltage to that wire. If the head lights get brighter or you hear the engine load down slightly you'll know the alternator is working and everything after that point is okay.

What'cha got in the other corner of the plug? The green wire with no stripe always goes from the alternator to the voltage regulator in the computer. It's the other one that is the 12 volt feed and appears to be missing on your car. Remember, I'm using a '92 service manual. Look at the black plastic terminal block on the back of the alternator where the wires go into. You'll see the dark green one. If the other one doesn't have an orange stripe, it should have a black one that is almost impossible to see. You should find a matching wire in the connector. My students used to make a lot of mistakes when troubleshooting my "bugged" cars when their paper clip probes didn't make good contact with the terminals in the connectors. Voltmeter probes give less trouble because they are stiff enough to wiggle around until they touch the terminal. Just don't get too carried away so the tip breaks off.

Okay, to stop this guessing game, I marched my fanny through ten foot snow drifts out to my shop and back, up hill, ... Both ways! To find a closer service manual. I came up with an '89 book which is considerably different than the '92 book I was using. Do you indeed have that 10-pin plug or do you have a 6-pin plug like shown here? This one shows a dark blue wire which is what Chrysler used for 12 volt feeds for decades but there's no white stripe. They still show the dark green wire going to the regulator which is consistent all the way back to 1970 models.

Darn the bad luck. Let's back up a minute and recheck the voltages on the two small terminals on the alternator with the engine running. If you'd prefer to troubleshoot this without having to run the engine, locate the automatic shutdown (ASD) relay and bypass the contacts. I can tell you how to do that if you tell me if you have three relays bolted to the left inner fender or if you have a fuse box under the hood with square relays in it. Otherwise just run the engine.

If you want to bypass the ASD relay, jump terminals 30 and 87 in the socket with a stretched out paper clip. You won't even need the ignition switch turned on. This way you can lean over the alternator without your tie getting caught in the belt.