Truck chargering @ 16.3 Volts
Man I just can't seem to get a good one. Got two Mopar ones from Summit and it still charges @ 16V+. Went down to the local parts store, and that one won't let it above 12.06V.
Lars, I'm new to the board but not Mopar. Here's some of my thoughts.
1. Make sure both ends of the battery cables are squeeky clean and tight that also includes and "extra" leads like the one that goes to the radiator support.
2. On your year truck you have 2 small gauge wires going to the back of the alternator...one is Red and the other is Green or Blue?
The Red wire gets 12volts with the key "on"..you can test there for voltage while wiggling the wire. High heat can make these wires brittle and the copper strands inside the insulation may break. If any break than you can develop problems. The Green or Blue wire goes to the voltage regulator, this line grounds out the field in the alternator to induce charging. The Green wire can also get damaged at the back of the alternator. If in doubt about either of the wire terminals...cut the old off and re-crimp new ones on the wires. Trace the Green wire back from the alternator to the VR and make sure the insulation hasnt melted some where along the way. If it has, you will get intermittent shorts to ground and wacky charging. It is usually run in the harness that runs along the valve cover area. Also the 2 position plug that snaps on to the VR may have spread female sockets in it or heat stressed wires. The connector can be replaced and picked up at any good auto parts store. Again check for 12volts at the red wire on the connector with the key "on" and flexing the wire.
3. You could have bad brushes or sticky brushes in the alternator that will cause charging problems.
4. Make sure the VR is well grounded to the firewall. The VR electronics get their ground thru the outer case and the mounting screws.
5. With all the voltage/current ups and downs your battery may have gone a bit braindead. If need be, place a load on the battery like turning on the headlights for about 10 minutes or more, disconnect the battery cables and place a trickle charger on the battery overnight.
6. If the battery cables have replaceable "emergency" type clamps on them, they can cause alot of problems as the copper strands in the battery cables oxidize much quicker when exposed to air. If you have a strange type battery cable on the positive side I can help you find a proper replacement.
7. Check to see if you have a plastic 6 terminal connector near the back of the passanger valve cover, if so, pull this apart, inspect and clean.
Let us know how you make out.
Regards-Stevo