Generator Light

I have a 96 Dodge Ram 1500,5.9.My generator light came on giving someone a jumpstart. I paid it no mind until on my way to work the radio went out.Then the dash lights faded.Then the headlights faded.Then the engine stopped.I walked the rest of the to work,came back with jumper cables the truck started without a jump.Anyway,I’ve changed the altenator and the battery still have the problem.What next?Anybody?

Long story short, I was helping a guy in a similiar situation with a 97 Explorer. He had changed the alternator and still was’nt charging.

After a quick look at the charging circuit wiring diagram I asked the guy if he had checked the “generator/voltage regulator” fuse.

No he had’nt & yes it was blown.

I dont have wiring diagrams for a 96 Ram, but take a look a the fuse list in your owners manual.

Is there a fuse in your charging circuit? Is it blown?

Check the fuseable link between the alternator output B+ terminal and the battery B+ terminal. It probably openned while you were connected to the jumpstarted car when it was cranked. You can confirm an open link, by measuring the voltage difference between the alternator B+ and the battery B+ terminal. If the voltage drop is more than ~ 0.3 volt DC, you have a confirmation. I am not exactly sure where in the wire bundle the fuseable link would be but a wiring diagram or fuse chart might indicate.

Let us know what you find.

I looked at the wiring diagram. Power from the battery goes through fuse #4 (30 Amp) through the ASD Relay (Automatic Shut Down). It, then splits. One leg goes to the alternator FEED on the PCM (Powertrain Control Module) {aka “engine computer”}. The other leg goes to, and through, the alternator to the PCM Voltage Regular terminal. Without this circuit active (energized), the alternator won’t produce. The fuse #4 is in the Power Distribution Center under the hood. The ASD Relay is in the relay box under the hood. Hopefully, the problem is one of these. The ASD Relay can be swapped with the horn relay. After replacing one, or both, items, check for 12 volts at the dark green wire terminal, and the dark blue wire terminal on the alternator. I don’t know if there is a fusible link. /// For future reference: Whenever a jump start is given, turn the ignition key OFF on both vehicles. Connect the cables. Now start the doner vehicle. Charge a few minuets. Start the disabled vehicle. WAIT! Let it run a few minuets to warm the engine and partially charge its battery. WAIT! Turn BOTH vehicle OFF. NOW, disconnect the jumper cables. IF the vehicle doesn’t re-start, re-do the procedure. Summary: Never connect, or disconnect jumper cables, to either vehicle, with the ignition keys ON. Why? The voltage spikes generated when the cables are connected or disconnected, can (ok! will!) damage electronics.

Going along with that, if you’re offering someone a jump, make a point to turn off your car’s stereo system, unplug any PDA or MP3 player gadgets you might have, and turn off your accessories such as heat/AC, headlights, etc. You want as little draw as possible on your car’s electrical system, because you’re adding a huge one by starting someone else’s car.