No battery charging on Dodge Stratus 2003

Question

I have a Dodge Stratus 2003 Sedan 2.4 Litre. The battery is not charging. Things we have done so far:

• Replaced alternator
• Replaced battery
• Replaced a related engine computer (assumably the PCM, but this wasn’t me)
• Replaced ASD relay
• Checked if new alternator was bad, triple passed bench test

The alternator is connected to the battery (I can read ~12.X Volts battery voltage on it when the car is off and there is continuity from it’s red lead and it’s body to the positive and negative battery terminals respectively), but it’s just not generating power (it should be ~13.X Volts). I guessed this problem might be the ambient temperature sensor near the battery going haywire, but I checked the OBD II data and the two temperature sensors I could find in there (without knowing which was what) both showed realistic values (84° and 78° as I recall, and the engine had just been running). I want to do continuity tests on the wiring, but I was unable to find a wiring diagram of the charging system: Sadly, this year and version seem to be one of the few that do not have a charging system wiring diagram for them in the Haynes repair manual I bought from AutoZone. Do you have any suggestions for further repairs or tests, or other sources of knowledge on the subject?

Answer 1

When replacing the alternator, overtightening the battery cable to the alternator post can break the internal wire, rendering the alternator inoperative. Less than hand tight is all that's needed. The side post, if observed, can be seen to turn if overtightening occurs with immediate damage.

Answer 2

Here's a wiring diagram from a google search for '04 Dodge Stratus.

Answer 3

Great! Glad the alternator tested fine. You'll probably need to examine both red and black battery cables, at their battery connections and main negative grounds. If there's corrosion on battery terminals, blush white powder, it's dried battery acid from older vented batteries and can eat copper wires under the heavy insulation on terminals. Some have to peel or cut away insulation to see severe wire corrosion, missing copper, loose crimped cable terminals. A tooth brush with warm water solution of baking soda will dissolve dried battery residue by bubbling immediately and neutralizing acid. Water rinse. Grease battery terminals after cleaning. Main negative cable(s) may be from battery to chassis, then chassis to engine block. Look for how and where your negative battery cable is routed to ensure battery negative connections at chassis and engine block. Red cable is split; one towards engine fuse panel and continuing on to the starter and alternator. This is basic main battery cable wiring virtually universal to all cars, trucks and suvs without needing wiring diagrams.