voltage problems

Where to begin.
I have replaced the battery twice, alternator three times, the fan once, checked the fan switch on the dash, made sure the stereo is wired properly, and replaced the selinoid, replaced the battery ground wire, and cleaned up other areas where components bolt to the frame.
When I turn on the heater fan, the voltage drops to 11.60v. When I use the headlights it drops, the turn signals cause it to drop slightly each time they flash, and flash really slow, same with the wipers.
The voltage drops from 14.70v to 11.60v and won't go back up until I disconnect the positive lead on the battery and the plug from the alternator and reattach them. Sometimes that will allow it to go back to 14.70v and sometimes it will stay at 11.60v.
If I run the headlights and fan, the voltage drops to 7.5v.
Also, sometimes when I turn the key ahead nothing will happen and othertimes it cranks over just fine> could the problem be a ground or could it be in the fused links on the selinoid???

Hi
Looks Like Voltage/curent regulator problem. By changing alternator 3 times you can probably eliminate voltage/current regulator malfunction. I am not sure if Voltage/Current regulator is located inside of the alternator that you have installed. I am not sure about Jeep, but some older cars have regulators located outside of alternator, on sidewall or firewall. If it is located inside of the alternator, then it is probably wiring problem.Try to move wires while it is working for example with headlights on. It looks like it is not sensing under voltage, and is not bringing alternator on line to charge battery. Inspect alternator wiring harness, and connectors. Also check belt tension. If I can’t help I hope somebody will, with more jeep experience.

Thanks for replying. I've tried moving all the wires around. The voltage regulator is built right into the alternator. I didn"t think about belt tension but last time I checked it was as tight as could go. I'll keep trying!!


Hi
Looks Like Voltage/curent regulator problem. By changing alternator 3 times you can probably eliminate voltage/current regulator malfunction. I am not sure if Voltage/Current regulator is located inside of the alternator that you have installed. I am not sure about Jeep, but some older cars have regulators located outside of alternator, on sidewall or firewall. If it is located inside of the alternator, then it is probably wiring problem.Try to move wires while it is working for example with headlights on. It looks like it is not sensing under voltage, and is not bringing alternator on line to charge battery. Inspect alternator wiring harness, and connectors. Also check belt tension. If I can’t help I hope somebody will, with more jeep experience.

First what year Jeep is it, if it has a computer, DON'T disconnect the battery when the engine is running and reconnect it. A very good chance you can fry your computer. NExt, I would remove the alternator and have them test it of the vehicle. You can get new bad parts.

Well, I changed the belt yesterday and that seems so far to have taken care of the problem. Duh. It wasn't so loose but it must have loosened up just enuf when it got warm to make the difference. Thanks!!!!!