By what you describe, it looks like you are getting an intermittent charge. You can check that wire for voltage when it is charging. Stick a sewing needle in the wire by the alternator. Connect the voltmeter red lead to the needle and black to a good engine ground. Have a helper start the engine and see if you get a voltage reading when the alternator is charging. After the test put some silicone or RTV on the needle hole to seal it.

The 6 pin connector is a junction for different circuits and the alternator circuit passes thru it.

To test for alternator ground you do not use the voltage scale, you use the OHM scale. You meter may not say ohm but look for the scale with the horseshoe figure with the open side down. Set the meter to 200 and you will see a 1 . when turned on. Now touch the two leads together and you will get a reading less than 1. something like 00.8 this is the zero resistance reading for that meter. This reading can vary a bit so do this test each time before testing and I use 00.8 just as an example. Also, some meters require that you change the red lead into a different socket for an ohm reading.

This test is called a continuity test and it does not matter which meter lead goes where. Connect one lead to the alternator case and the other to a good engine ground or battery negative. You should read 00.8 or close to it. A higher reading means more resistance and a poor ground.

You can test a wire or a circuit doing a continuity test. Connect one lead to one end and the other lead to the other end. Again you should read close to 00.8 and higher means resistance and if you get a 1 . that means there is a break in the wire or circuit.

One important thing A CONTINUITY TEST IS ONLY DONE ON A DEAD CIRCUIT OR WIRE.

If the circuit or wire is powered, you do a voltage test.

You may have to trace that wire to see where it goes.

 

if alt ternator is not grounded to engine thru the mounting brackets and bolts the volt meter will show no volts

 

im covering all the bases i sent him apdf wiring diag last nite showing what the wires run to on his year xj yellow is switched from ignition switch the tan and green are to gauge or alt light if im reading him right he has power on the yellow when running but nothing on tan and green

 

Ok i get what your saying, so if he doesnt have power or signal from the tan/green(Gauge/light) while the car is running he wouldnt be getting a reading on the gauge/light?? I remember reading earlier that the gauge did move intermediately would go to 13 drop to 9-10.. etc Ok.. So he is having signal from that tan/green wire.. That means all his connections/connectors are working properly. (He tried to get a reading from the pigtail of the alt.) No signal.. So i feel the problem might lye on the alt itself...and between the pigtail connector.

I agree with Free, that you should test the alt output charge on alt and attached the neg to a common ground. If its charging around 13.5 to 14 then your alt is good ... and charging.

Also where is your positive charge from alt. going?? to the + battery or to the Fuse block? On mine its to the fuse block(98) the battery cant always be recieving a charge, it will kill it in the end. It there to supply enough charge to the starter and when the key is on acc..

 

i would think the regulator controls that thru the yellow when it senses to much current coming in it regulates the curren going out ?

 

.... Then what would be the purpose of the tan/green.. So far we have found that theres no power go towards the alt. from tan/green. And there is power going to alt. from yellow. The yellow is the regulated wire giving the source for the alt to charge. There need to be a signal/voltage being sent to the gauge. i dont think it would be sent from another source, it should come directly from the alt which the tan/green wire specifies as such. Gauge/ light. I dont know if hes tried testing the output signal from the alt on that wire at the pigtail. I would have to read through again..

 

if its the same body style it should

 

i found a diagram for the wagoneer but it was a v8 so i dont think it would work and the alternator description didnt match the OPs.

 

just so you guys that havent seen the diagram yet...here's what 'free' sent. I just located it and highlighted so you could see...actually a pretty good diagram of the whole electrical system! 10 pages of this!



Now Ive got to go do some testing as stated by ET and Free... appreciate everyones input on this...if i can figure this out, I think it'll help others since ive covered almost all of the Alt setup lol

 

could be in the computer I did some mudding few weeks back and my alternator took a dump then the new one was overcharging at 18volts I traced it back to the volt regulator in the computer good luck

 

well just did a ground test, engine off. Multimeter lead on Alt casing and Multimeter lead on good engine ground. Got a .008 exactly. Tested it a few times in different spots on the Alt.

So is this something I do with the engine running as well, but switch it to voltage? I think I did it earlier in my troubleshooting, and was getting a solid voltage that the battery read, nothing more (which told me there was no extra charge).



EDIT:

I also just went out and did the needle thing without the engine running.
Needle through tan/black wire (orange/black, whatever).

touch it with red multimeter and black multimeter to good ground, stays a 1.
if i keep the black multimeter on the ground, but put the red multimeter to the base where the needle goes into the wire, i get a 189-198 or something. This is the same thing If i touch the red and black multimeters together.

what does that say?


K, redid that test. Odd...
Mult lead on ground and mult lead on needle reads in the 30's range.
Mult lead to mult lead its .008....

I then tested the neg battery cable. Mult lead on ground at block, mult lead on neg batt terminal end, i get the 30's range.

did it a few times now, about the same. But it does jump all over before settling in a lot of cases...

im lost.

 

The ground test on the alternator is just to insure you do have a good ground. By the reading you got, you do have a good ground. This test is not needed during engine running.

Looking at the schematic you posted, mine is similar but it does not show the gauge or light connection. Do you have an alternator light or a volt/amp meter or both?

Since you stated that you do get a charge, intermittent, during engine running, the needle test would be done with the engine running to see if you read any voltage on that wire.

Your quote "
touch it with red multimeter and black multimeter to good ground, stays a 1. "

this indicates that there is a break in the wire somewhere. If this wire goes thru the ignition switch that would be the case. Did you have the ignition switch on during this test?

I'm not quite getting your second test.

The real test with the needle is to test for voltage with the engine running and if the alternator charges intermittently.

The yellow wire is the alternator field wire. It supplies voltage so the alternator can start charging. The orange/black should be the sense wire. This wire wherever it is connected should sense the condition of the electrical system and that tells the alternator to turn on and off to maintain the set system voltage.

With the engine running you should read voltage on this wire. That is why the needle test is done with the engine running. If the alternator provides any charge you should read voltage.

 

Post or PM me an email address and I will send you the schematic.

 

my email is: fastcar94z@hotmail.com

Voltage test with engine running, Mult Neg lead on battery ground, Mult Pos lead on needle, i get a .83 pretty consistantly.

 

tell me if im wrong the yellow energizes the alt the tan is for gauge correct the cable tha goes to the battery is how the alt charges the battery disconnect the cable to battery start xj check for charge at the post on alt with cable from bat off of alt?