How do i use in cab 5th wheel unlock properly?

year/make/model??? 2x4? 4X4?? You may have more than one problem. The bumpy problem sounds like a wheel balance issue. The grinding could be anything with limited info given

The only thing that comes to mind is that in 5th, the rpms may be so low that you are running on low speed potion of ignition module, getting weak spark and not burning fuel properly. This could be true in all gears at low rpms, but you would not notice it as much because you probably keep the revs up more in lower gears. Just a thought.

You have plenty of truck to tow that thing around. I would have the 20 year old tranny serviced and ask the transmission shop if its going to hold up to the pressure.

If it was an option the harness is between the cab and the box. The harness is all taped up about 12" in length. You have to crawl under the truck to find it. If the 5th wheel harness was not optioned you will have to use the rear trailer harness that is standard equiment. It is located at the rear of the spare tire or tucked above depending where the truck was made. Good luck Kirk fe6fc

Could be a fuse or a wheel speed sensor; next, check the tone rings on the axle shafts and see if they are not broken.

I quote this information from Jeep lover's...

The amber ABS warning lamp is located in the instrument cluster. It is used to inform the driver that the antilock function has been turned off due to a system malfunction. The warning lamp is controlled by the CAB and/or the main relay through an in-harness diode. The CAB controls the lamp by directly grounding the circuit. The main relay grounds the lamp circuit when it is de-energized.
The re BRAKE warning lamp is located in the instrument cluster. It can be activated by application of the parking brake or leak in the front or rear wheel brake hydraulic circuit.
The antilock brake controller (CAB) is a microprocessor-base device that monitors wheel speeds and controls the anttlock function.
The primary functions of the CAB are:
- monitor wheel speeds
- detect wheel locking tendencies
- control fluid pressure modulation to the brakes during antilock stop operation
- monitor the system for proper operation
- provide communication to the DRB while in diagnostic mode
- store diagnostic information in non-volatile memory
The CAB continuously monitors the speed of each wheel. When a wheel locking tendency is detected, the CAB will command the appropriate valve to modulate brake fluid pressure in its hydraulic unit. Brake pedal position is maintained during an antilock stop by being a closed system with the use of 3 accumulators. The CAB continues to control pressure in individual hydraulic circuits until a wheel locking tendency is no longer present. The CAB turns on the pump/motor during an antilock stop.
The antilock brake system is constantly monitored by the CAB for proper operation. If the CAB detects a system malfunction, it can disable the antilock system and turn on the antilock warning lamp. If the antilock function is disabled, the system will revert to standard base brake system operation.
The CAB inputs include the following:
- four wheel speed sensors
- stop lamp switch
- ignition switch
- main relay voltage
- pump/motor relay output
- diagnostic communication ISO/K
- G switch (acceleration switch)
The ABS main relay is located in the power distribution center (PDC). The main relay has two functions. First, when the relay is energized, it supplies power to the valve/solenoids in the valve block assembly and the pump/motor relay coil. Second, when the relay is de-energized, it supplies a ground to turn on the ABS warning lamp. The main relay is controlled by the CAB. The CAB energizes the main relay when it receives an ignition input signal.
The ABS pump/motor relay supplies power to the pump/motor. It is also located in the PDC. The relay coil is powered by the main relay and the coil ground is controlled by the CAB. The pump/motor relay is a special five-terminal relay and should not be replaced with a standard relay.
One wheel speed sensor (WSS) is located at each wheel and sends a small AC signal to the control module (CAB). This voltage is generated by magnetic induction when a toothed sensor ring (tone wheel) passes by a stationary magnetic sensor (wheel speed sensor). The CAB converts the AC signals into digital signals for each wheel.
The front wheel speed sensor air gap is NOT adjustable. The correct front wheel speed sensor air gap is from 0.40mm to 1.3mm. Preferred rear sensor air gap for drum brake systems is 1.1mm. Acceptable air gap range is 0.92mm to 1.275mm. For rear disc brake systems, the preferred rear sensor air gap is 1.2mm. Acceptable air gap range is 0.95mm to 1.45mm. All wheel speed sensors have a resistance between 900 and 1300 ohms.
Correct antilock system operation is dependent on tone wheel speed signals from the wheel speed sensors. The vehicle's wheels and tires should all be inflated to the recommended pressures for optimum system operation. Variations in wheel and tire size or significant variations in inflation pressure can produce inaccurate wheel speed signals; however, the system will continue to function when using the mini-spare. When driven over rough road surfaces, the rear wheel speed sensor signals may be erratic and cause a false trouble code (drum brakes only).
Diagnostic trouble codes are retained in memory until erased using the DRB, or automatically erased after 50 key cycles.
Ensure you are using a DRBIII scan tool properly connected to the data link connector located under the dash to the right of the steering column.
Select "Anti-lock Brakes" the "Teves ABS". Turn the ignition on.
Read and record all ABS diagnostic trouble codes. If the "Valve Power Feed Circuit" trouble code is present, it must be repaired before prior to addressing any other DTCs.
If there are no trouble codes present, select "Inputs/Outputs" and read the brake switch input as you press and release the brake pedal. If the display does not match the state of the pedal, check for 8 volts at the brake lamp switch output circuit. If the voltage is not present, repair the open brake lamp switch output circuit. If the voltage is present, replace the CAB.
If the display does match the state of the pedal, read the "G-Switch" status, with the vehicle on a level surface, both switches should read "CLOSED". If the status is not correct, make sure the G-Switch is properly mounted and connected (under the driver's side rear seat). If it looks correct, you'll have to check for voltage to the G-Switch.

Hope helps.

the gvwr is the calculated weight the the truck can carry in the cab and the bed combined, it is not the towing capacity, the towing capacity can be found in your owners manual. I hope this helps you, good luck !

look in the driver door it will tell you i pull a gooseneck with 30000 on it all the time with no prolbem my wieght is 30000

That info should be on a sticker in your door jam. The aftermarket intake won't make any difference as far as towing capacity.

possible faulty heater resistor block or control head

Well, you say the noise is in 1st, 2nd, 3rd, and 5th, and I assume this is an overdrive tranny with the overdrive in 5th.

This means your 4th gear is more than probably direct (1:1) ratio.

Meaning you have a bad countershaft bearing(s), or gears...

In direct, your countershaft still spins but carries no power/torque to the wheels (it is basically just freewheeling), input shaft speed/torque goes directly/is locked to the output shaft, so you don't hear the noise; in any other gear, where the countershaft bears a load, you hear the bad bearing or gears.

Either way your tranny has serious internal issues and needs to be rebuilt before it destroys itself.