89 Wrangler; 42.L; no electrical extras. Subject of a previous post and I have done everything suggested but still having a problem so I thought I would recap and see if anyone has any additional diagnostic suggestions.
While offroad several weeks ago, we got into a tough spot and had to winch. During the process, we burned the positive cable terminal and ruined the positive battery terminal. I am not sure what caused the problem; don't know if the battery terminal was loose; heavy winching. I was also too busy trying to save the Jeep to notice what the voltmeter was doing.
Was able to get home on the battery only. Replaced battery and positive terminal connection with a military terminal and noticed the overcharging problem. In hindsight, I am not sure if the overcharging problem existed before or after the melt but I had not noticed a problem with the volt gauge before that trip.
Battery is new and has been checked; also swapped out a battery from another vehicle and same problem. Multimeter shows battery at 12.5-13; turn key on and dash voltmeter gauge only reads 10-11. Starts up easily but multimeter and voltmeter gauge jump to 14 at idle; increase rpms and needle increases to 17. Multimeter confirms 17 volts going to battery.
Checked, cleaned, and tightened all connections (including connection on firewall); had alternator checked at two parts stores and both say it is good; also replaced alternator belt.
Before I start buying and replacing parts and pulling the harness wiring out of the plastic sheathing, can anyone suggest an approach and in what order? I have a Haynes manual but it isn't much help.
1. Is is possible that the alternator is actually bad but reads OK on the test bench?
2. Why does the dash volt gauge read low when key is first turned on in comparison to the multimeter? Is there anything about the low reading that suggests a place to look?
3. Read something about the "sense" wire which I believe is the red wire connected to the threaded post on the back of the alternator. Is there anything to test with it that might help?
4. Read other posts about checking engine codes. If I got the codes, would that help anyone?
5. Finally, can anyone help me identify the wires going to/from the alternator and from the positive terminal to the firewall?