Starter Wires Question

Hey Y'all,
I have a '99 Sport, Auto, 4x4, 136k, loads of "personality" that I have not been able to get started for the past week. It began turning over very slowly when it would start about a week or two before she finally gave up...

What it is doing:
When i turn the key, I am getting a click from the front, what i think is either the relay or starter? But, only the first one or two times, then nothing.

I have tried:
-Took the starter off, cleaned it up and had it checked at autozone, it passed
-I was able to jump it with a screw driver once, but have not been able to since then. I get the same single click, which makes me think starter?
-Replaced ignition switch in column
-Cleaned up all of the connections that I could find (battery posts, grounds, starter posts, the wire that goes to the solenoid)
-I tried starting in N, wiggling the shifter, bypassing the NSS through the relay, all to no avail
-I tested the voltage at the battery, starter, and solenoid. Everything tested ok (12.6 resting and 11.8 when cranking) i think, except I was only getting 9.8-10.2 at the solenoid which is where the problem is I think.
-I tried working my way up the wire to see where I was losing voltage, but got a reading of 0 at the next connector....

So, I guess my question is what is the name of the connector that the brown wire connects to (it also has 3 other wires, 2 that connect to the alternator and 1 that I didn't really track down) and should that be my next piece to replace? I have searched for "4 wire connector" "ignition wires" "brown wire" "pigtail" "wiring harness".

Thanks in advance for any suggestions, I am really at a loss...

First off...where are your meter leads when you are getting insufficient voltage at the solenoid and 0 at the next connector?

I have the negative lead on the negative post and am probing about with the positive... is that not the way to do it? i admit that i am new to electrical issues....

No that is the way to get available voltage. Just making sure you were not using voltage drop. So you have approximately 10 volts at which terminal on the solenoid?

on the actual tab that the connection attaches to, behind the connection on the metal part

There should be one large terminal on top with a large battery cable going to it. Underneath should be another large terminal with a cable going to the starter itself. There should be two smaller terminals, one on the left and one on the right. Are you speaking of the top large terminal?

no, on my starter i have two large terminals. one coming from the battery and the one going to the starter. then i have one small terminal on the solenoid that only shows voltage when the key is turned.

thank you by the way. i really appreciate you taking time to help me out

Not a problem. Ok. To oversimplify the small terminal is from your starter relay. It supplies 12v to the solenoid S terminal when you crank. 12 volts should be on the upper large terminal which should transfer to the lower one when you crank. Have someone turn the key while you check the lower large terminal.

thank you, i did not check that terminal and i will try that tomorrow. Now some more questions...
i am looking for 12 volts to the bottom terminal, correct?
if i do not have 12 volts there, that would mean that the wire from the solenoid to the starter motor is the problem?

If you have 12 volts to the upper terminal and 12 volts to the smaller S terminal but not 12 volts to the lower terminal that tells you that your solenoid is bad which usually is best replaced as a unit with the starter. If you have 12 volts to the upper terminal and smaller S terminal but you do have 12 volts to the lower but the starter still does not turn then you have a bad starter motor which again is replaced as a unit.

But I have 12 to the positive and only 10 to the S terminal, is that a starter issue or a wiring issue do you think? again, i am new to electrical issues, so i am sorry if i repeat questions, i just am trying to wrap my head around the concept

It means you are dropping 2 volts over the course of the circuitry. All your meter does in voltage mode is tell you the difference between the two leads. So ideally your battery negative will be zero and the positive will be 12.6 so the difference between the two is 12.6 and that is what your meter shows. You can use that to your advantage by using what is called voltage drop testing. This technique allows you to test the resistance of a circuit with it in action so to speak. So go to the S terminal with one lead and and the output from the relay with your other lead. You will have to jump the relay with a paper clip or wire to do this test. Ideally this will show close to zero because they should both be approximately 12 volts. Understand? In your case it will probably show about two. Then slowly narrow down the circuit into smaller chunks to find where your high resistance is.

awesome, i will try that too. and thank you, that explanation makes more sense than others i have read. i am headed to bed now, i will update you tomorrow after i have tried these things.

WOOHOO!
I found that i was losing all voltage between the s terminal and its connector. i am going to cut it out and try to find a new one to splice in.
thank you joejeep92 for your explanation of a volt drop test and your patience, i appreciate both

Awesome man. Glad it worked out.

Ok, now I am getting voltage to the starter, but still not starting... I had the battery charged then did the steps from this link (http://www.aa1car.com/library/voltage_drop_testing.htm), all of the readings were within normal limits, but still nothing.
It does now click every time I try to turn it over, which I guess is progress?
Anywho, I tried everything again today, and it all checked out again, though with slightly lower voltage as it hasn't had an alternator to charge it.
So, here are my questions:
1. How many volts are needed to turn the engine over? Today I had 12.25 resting and 12.09 cranking at the both the battery and starter...
2. I had 2 odd readings that were not on the list, On the 1.5v setting on my meter I got 12.05 with my pos lead on pos term and neg lead on starter body cranking. And, again on 1.5v, i got .02 with pos lead on pos post and neg on pos starter post cranking...Do either of those mean anything? I was just kinda exasperated and started putting leads places
3. It still sounds like the starter to me, Anyone else have any ideas?

Thanks guys, I appreciate y'all's help.

It is either starter or battery, if wiring is good. Have the battery load-tested if you haven't already. Some show plenty of voltage, but fall flat when you crank the engine.

Cheap test for battery: jump-start from another running vehicle. If it cranks and fires up, your battery is toast.

Yup, it was the starter. I finally convinced the guys at autozone that yes, it will pass the test, but no, it will not start my engine. So, I got a new one under warranty, installed it, and she fired right up first try... I'm pretty sure I did the first set of tests wrong and "fixed" a couple of things that didn't need it, but I learned a lot about my starter circuit. Thanks for your help guys, I appreciate it. I am so happy to have jeep up and running again.