Alternator then why does it say directly on a new alternator that you buy that it is externally regulated

It would be more cheaper to buy a new car than to try and fix the car that is broken. Both the alternator and the voltage regulator need to be replaced for your car.

if the alternator is brand new then it is an external voltage regulator
have an auto electrician check the charge system for you

Looks like the regulator can be replaced. But it is on the backside of the alternator. You may not be able to find it.. Without buying the alternator.

It's best to buy a new alternator.

IDENTIFICATION

There are 4 different types of alternators found on the years and model ranges covered in this information:

1. Rear Terminal, External Regulator, External Fan Alternator
2. Side Terminal, Internal Regulator, External Fan Alternator
3. Leece-Neville 165 Ampere Alternator
4. Integral Rear Mount Regulator, Internal Fan Alternator

Rear Terminal, External Regulator, External Fan Alternator
This unit utilizes a separate, external electronic regulator. The regulator is non-adjustable. The rear terminal alternator was standard equipment on 1987 trucks, and can be found on some 1992 motor home chassis models equipped with the 7.3L diesel or 7.5L gasoline engine.
Side Terminal, Internal Regulator, External Fan Alternator
This unit was optional on 1987, standard on all 1988-92 models and standard on 1993-96 models equipped with the 4.9L and 7.5L engines. The regulator in integrated within the alternator body and is not adjustable.
Integral Rear Mount Regulator, Internal Fan Alternator
This alternator is standard equipment on all 1993-96 models equipped with 5.0L, 5.8L gasoline engines and 7.3L diesel engines (except the 1996 F-Super Duty models).
Leece-Neville 165 Ampere Alternator
This unit is optional equipment on some 1989-94 trucks and ambulance packages. A separate, electronic, fully adjustable regulator is employed in this system.
Mitsubishi 215 Ampere Alternator
This unit is found on 1996 F-Super Duty models equipped with the 7.3L diesel engine. The regulator is integral and the fan is external.

REMOVAL & INSTALLATION

See Figures 1, 2, 3 and 4

Fig. Fig. 1: Disengage all wiring harness connections from the alternator

Fig. Fig. 2: Once it is unbolted, maneuver the alternator from the engine compartment

Fig. Fig. 3: Side terminal alternator

Fig. Fig. 4: Rear terminal alternator

1. Disconnect the battery ground cable.
2. Remove the adjusting arm bolt.
3. Remove the alternator through-bolt. Remove the drive belt from the alternator pulley and lower the alternator.

Some engines are equipped with a ribbed, K-section belt and automatic tensioner. A suitable tool must be made to remove the tension from the tensioner arm. Loosen the idler pulley pivot and adjuster bolts before using the tool..

1. Label all of the leads to the alternator so that you can install them correctly and disconnect the leads from the alternator.
2. Remove the alternator from the vehicle.
3. To install, reverse the above procedure. Observe the following torques:
   
   Pivot bolt: 58 ft. lbs. (78 Nm) Adjusting bolt: 25 ft. lbs. (34 Nm) Wire terminal nuts: 60-90 inch lbs. (6.8-10.1 Nm)
   

the wiring is bad. go through your harness from your alternator to your external regulator (if the alternator is externally regulated) then that to your starter solenoid and to your battery. if there are any cracked wires, that could be the problem.

where did you buy the new alternator? Are you sure the alternator is good? Have the alternator tested before you spend time/money on your other components. If your wires are damaged or corroded, that's another problem.

I am assuming you are now using a 1976 style GM alt.
The most common and popular model.
You need one 10 gauge wire from the battery to the alternator output.
This can be run directly from the battery +.
Run a short 10 gauge wire from alt output to large wire at regulator plug on alt.
Run small wire on alt reg plug to Bat light wire.
A new alt regulator plug pigtail can be bought at any parts store and is recommended.

The existing regulator should have the connections marked.
One of those wires will be the bat light wire if needed.
If you have a amp meter or voltmeter in the vehicle.....use your existing large output wire (usually red) to hook up to the new alt output connection.

If this is a 2000 JEEP WRANGLER TO MY KNOWLEGE this vehcle does not have an external regulator. ITS built into the alternator. There is 6 sylinder and 4 cylinder wrangler in that year and neither have an external regulator. Good luck and conatc if you needmore help. Check this link out..http://www.autopartswarehouse.com/details/QQJeepQQWranglerQQNSAQQAlternatorQQ19992000QQUSALT-5214.html