My problem is that the center high mount stop lamp on 2004 jeep wrangler does not come on when brake lights are lite. I have already replaced the bulb to no avail. do you have any suggestions?

Check battery voltage and ground at the tail lamp assembly . lite blue wire is battery voltage & black is ground . Does your vehicle have a trailer connection ? Check for corrosion in connection. , corroded ground - g105 splice pack G105
Ground splice pack in the engine compartment - left side inner fender near EBCM

Stop Lamps
The STOP fuse in the underhood fuse block supplies battery positive voltage to the normally open stop lamp switch. When the driver presses the brake pedal, the switch contacts close and battery positive voltage is supplied to the stop lamps and center high mounted stop lamp (CHMSL) which are grounded at G105.

https://www.youtube.com/watch?v=SO-eKuhCOqc

Stop Lamps
The body control module (BCM) is responsible for controlling the stop lamps. When the driver presses the brake pedal, the BCM will receive a signal from the brake switch. The BCM then supplies battery positive voltage to both left and right stop lamp assemblies and to the center high mounted stop lamp (CHMSL).

Which one isn't working ? Left - right or center high mount

Do you know anything about automotive electronic's ? The brake pedal position sensor is a input to the BCM - body control module ,the BCM turns on the stop lamps . Possible short in the (CHMSL ) - center high mount stop lamps , wiring etc.... Causing problem inside the BCM . Do you know what wiring diagrams are ? Free one's here http://www.bbbind.com/free-tsb Enter vehicle info. year , make , model an engine size . Under system click on lighting , then under subsystem click on exterior lighting . Click the search button then the blue link's . First diagram show's the brake pedal position sensor input to the BCM ,lower right . Second diagram show's BCM power supply to the third brake light (CHMSL) . Having a qualified repair shop with a professional scan tool to check for DTC'S - diagnostic trouble code's could save a bunch of time in diagnosing the problem .
DTC B3903
The body control module (BCM) supplies voltage to the center high mount stop lamp (CHMSL) and the powertrain control module (PCM) when the stop lamps are active.
DTC B3903 Stop Lamp Relay Circuit

Stop Lamps
The body control module (BCM) is responsible for controlling the stop lamps. When the driver presses the brake pedal, the BCM will receive a signal from the brake pedal position sensor. The BCM then supplies battery positive voltage to both left and right stop lamp assemblies and to the center high mounted stop lamp (CHMSL). The stop lamps are grounded at G401 and G403. The CHMSL is grounded at G302.

Maybe a problem with multifunction switch?
Do the hazard lites work?
Does the high-mount brake lite work? The reason I asked, the high-mount brake lamp and lower brake lamps are wire differently. The lower brake lites are wiring through the turn signal switch.
bbbind.com has free wiring diagrams.

Do you know how to test using a DVOM - digital volt ohm meter ? Is there B+ voltage going into the brake light switch ? An coming out when the brake pedal is pressed ? What fuse's ? There is only one fuse for the brake lights !
The BRAKE SW fuse in the RH I/P fuse block supplies battery positive voltage to the normally-open stop lamp switch. When you press the brake pedal the switch contacts close and battery positive voltage is supplied to the left and right stop lamp assemblies and to the center high mounted stop lamp (CHMSL). The left and right stop lamp along with the CHMSL are grounded at G302.
Do you know about the right insturment panel fuse box ?
Stop Lamps Inoperative
Step
Action
Yes
No
Schematic Reference: Exterior Lights Schematics
1
Did you perform the Lighting System Diagnostic System Check?
YES - Go to Step 2
NO - Go to Diagnostic System Check - Lighting Systems
2
Press the brake pedal.
Do all of the stop lamps illuminate?
YES - Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems
NO - Go to Step 3
3
Are all the stop lamps inoperative?
YES - Go to Step 4
NO - Go to Step 7
4
Inspect the BRK SW fuse.
Is the fuse open?
YES - Go to Step 14
NO - Go to Step 5
5
Disconnect the stop lamp switch.
Using a test lamp connected to ground, probe the battery supply voltage circuit of the stop lamp switch connector.
Does the test lamp illuminate?
YES - Go to Step 6
NO - Go to Step 13
6
Install a fused jumper between the battery supply voltage circuit and the stop lamp switch signal circuit of the stop lamp switch connector.
Do the stop lamps illuminate?
YES - Go to Step 12
NO - Go to Step 17
7
Determine if the center high mounted stop lamp is inoperative or the stop/turn lamps are inoperative.
Are the stop/turn lamps inoperative?
YES - Go to Step 8
NO - Go to Step 9
8
Do the turn lamps operate normally?
YES - Go to Step 17
NO - Go to Turn Signal Lamps and/or Indicators Inoperative
9
Disconnect the center high mounted stop lamp.
Using a test lamp connected to ground, probe the stop lamp switch signal circuit of the center high mounted stop lamp at the harness connector.
Press the brake pedal.
Does the test lamp illuminate?
YES - Go to Step 10
NO - Go to Step 15
10
Using a test lamp, probe between the stop lamp switch signal circuit and the ground circuit of the center high mounted stop lamp with a test lamp.
Press the brake pedal.
Does the test lamp illuminate?
Go to Step 11
Go to Step 16
11
Inspect for poor connections at the harness connector of the center high mounted stop lamp. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.
Did you find and correct the condition?
Go to Step 20
Go to Step 19
12
Inspect for poor connections at the harness connector of the stop lamp switch. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.
Did you find and correct the condition?
Go to Step 20
Go to Step 18
13
Repair a open or high resistance in the battery supply voltage circuit of the stop lamp switch. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you complete the repair?
Go to Step 20
--
14
Repair a short to ground in one of the following circuits:
• The battery supply voltage circuit of the stop lamp switch
• The stop lamp switch signal circuit of the stop lamp switch
Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you complete the repair?
Go to Step 20
--
15
Repair a open or high resistance in the stop lamp switch signal circuit of the center high mounted stop lamp. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you complete the repair?
Go to Step 20
--
16
Repair an open or high resistance in the ground circuit of the center high mounted stop lamp. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you complete the repair?
Go to Step 20
--
17
Repair an open or high resistance in the stop lamp switch signal circuit of the stop lamp switch. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you complete the repair?
Go to Step 20
--
18
Verify the stop lamp switch adjustment. Refer to Stop Lamp Switch Adjustment . If OK, replace the stop lamp switch. Refer to Stop Lamp Switch Replacement .
Did you complete the repair?
Go to Step 20
--
19
Replace the center high mounted stop lamps. Refer to High Mount Stop Lamp Replacement .
Did you complete the repair?
Go to Step 20
--
20
Operate the system in order to verify the repair.
Did you correct the condition?
System OK
Go to Step 2

check the lt blue wire at upper lamp,(under trunk lid trim panel) for 12 volts when brake is applied. if no voltage,check same color wire at brake lamp switch for voltage.(by brake pedal).if no voltage replace stop lamp switch asm. if voltage is detected at rear by lamp then replace CHMSL asm.(center high mount stop lamp). this lamp is made of many LED's,if some work and some don't you will need to replace lamp asm. can be repaired by a trained GM tech, possibly. there is no seperate fuse or relay for this lamp,only a stop lamp fuse.

I suggest to check your tail lights. sometimes if they go out, the cruise control will not work. Oh and also, what i did when this happened to me, I checked under the brake pedal and pushed and pulled the little button that activates the taillights and it worked again. It may have gotten stuck..
The brake light fuse may have popped..

ALSO: -- There seems to be a recall for this..
CERTAIN PICKUP TRUCKS MAY EXPERIENCE THE PERMANENT LOSS OF BRAKE LAMP FUNCTION OR BRAKE LAMPS THAT ARE ILLUMINATED AT ALL TIMES. THE CENTER HIGH-MOUNTED STOP LAMP (CHMSL) IS AFFECTED IN BOTH INSTANCES. ALSO, IF EQUIPPED, THE CRUISE CONTROL WILL BECOME INOPERATIVE. ANY TRAILER BRAKE LAMPS WHICH ARE CONNECTED TO THE VEHICLE'S BRAKE LAMP WIRING WILL MIMIC THE VEHICLE'S BRAKE LAMPS WHEN EITHER CONDITION OCCURS.

just follow the wires from the brake lights and you'll see the ground. its probably coroded

Did you check the fuse,#23 in JB center,this is hard wired to brake swicth, PK/BL should have 12v,if ok procede, wh/br will have 12v when brake is pushed on.if not replace the switch, jump the 2 wires and light sould come on, same feed goes to high mount lamps, does the info console warn of no lights, if you need more info, just ask. GOOD LUCK, RDJRP

Does the CHMSL ( Center High Mount Stop Lamp ) work ?

If this does not work, check the BPP ( Brake Pedal Position ) Switch, mounted on the brake pedal lever. There should be 4 wires to it, 2 are for the shift interlock, the other 2 are the brake lamp switch.

The brake lamp switch feeds direct the CHMSL and the MFS for the Stop/Turn combo lamps.

Without a CHMSL, I would suspect the BPP switch.

The wire colors on the F-150 are Light Green & Light Green w/ Red stripe for the stop lamp circuit. If you have this color combo, unplug the connector, and try jumpering the 2 together, to see if you have brake lamps.

Assuming the mechanic already checked the fuse for the BPP