4X4 ENGAGING

When you are in 2wd sitting at a stop, in park or neutral, and you press four high, do you hear anything, and does the light continuously flash or revert back to 2wd. How about four lo, you should definitely hear and feel that shift, as well as the gear reduction, does it continue to flash, or revert back to 2wd.

Which wires(what colors) at what switch did you check? At the actuator I am showing a two wire connector, a light blue wire and a black wire. The black wire is shown as hard wired to ground(g105). There is also a front axle switch that has a two wire connector, the same lght blue circuit as the actuator, and a black white hat looks like, in theory, should be grounded by the transfer case control module. There is a bulletin, and a revised schematic, if the new style front axle actuator has been installed.

Ok, I put the truck in the garage where I could get some light on the situation. I un-plugged the connectors at the actuator I am getting around 13vdc when I press the 4wdh or 4wdl buttons. I might be wrong but it sounds like the actuator is not activating. A couple of questions. If it is the actuator and I take it out will the gear oil drain out when it is removed if so where and how much oil do I replace it with. Also what is the other two wires for that go to the transfer above the actuator.

Here are some wiring diagrams (below) and guide on how to test for power, it sounds like a switch has gone out.

https://www.2carpros.com/articles/how-to-use-a-test-light-circuit-tester

and

https://www.2carpros.com/articles/how-to-check-a-car-fuse

Please let us know what you find.

Cheers,

Was that 13v using the ground at the connector for the actuator? If you remove the actuator, you should not have much oil leak out, maybe even less to none if you lift the RH front side of the vehicle a bit. If you do have some loss, the fill plug is on the LH side of the differential, above the drain plug toward the front. The fill plug is 15mm, the drain is 13mm. Fill it through the fill hole until fluid runs out.
The wire colors at the actuator should be light blue, and black, is that correct? What are the wire colors that go o the other item that you are speaking of. My guess is, it is a switch that will confirm that the actuator is locked in, this may be what will stop your lights from flashing. The problem with the service information that I am referencing, is it gives no component location description or views. I am going off of the wiring schematic from ALLDATA.

That switch actually sends the message to the transfer case control module. A quick test would be to jumper the terminals of that switch together. If this stops the lights from flashing, and you are getting the signal to the actuator, then I would suggest a bad actuator. You might be able to bench test the actuator by applying power and ground to it. The symbol in the actuator shows that it is a coil of wire, or a resistor of some sort. You could also check the continuity of the actuator. If it is open, then it is safe to say it's faulty. Service information does not specify an electrical specification for the actuator. It should have some resistance, probably like a fuel injector or similar, possibly 10 to 20 ohms I would guess. Substantially low resistance could indicate shorted windings, excessively high could indicate high resistance or open circuit. I believe the case of the actuator is plastic, so if it was shorted to the case it would not find a path to ground. The following bulletin may interest you if you need to replace the actuator. I am not certain if this upgraded part and procedure address just the complaint as stated, or if it is necessary in the case of any actuator replacement.
Drivetrain - Slow Or No Engagement of Front Axle.

I am wondering if that is not indicating there is a system fault. Explain the flashing in detail, and I will provide you with the info that I have. When you are just turning the truck on, in 2WD, the indicator is?, on solid?. Say you make your first request to 4HI, does all the indicators flash, or just 4HI? Does it continue, or revert back to 2WD? What about 4LO? It is capable of displaying trouble codes through that switch(indicators), it requires jumping a terminal at the DLC connector, are you familiar with that connector?

Fig. 25 Data Link Connector Pin Terminals

Displaying Diagnostic Trouble Codes

Install jumper wire between DLC terminal 13 and ground, Fig. 25 . The DLC is located under the lefthand side of the instrument panel, right of the steering column.
Turn ignition switch to On position.
Wait three seconds, then observe transfer case switch status lamps.
Reading Diagnostic Trouble Codes
The transfer case status lamps will flash to indicate the DTC's stored in memory. If only one DTC is stored in memory, that DTC flashes repeatedly with a three second delay between flash sequences. If more than one DTC is stored in memory, the first DTC flashes once, then the next code is flashed. This sequence continues to flash until the jumper wire is disconnected.

Fig. 28 Test A: Status Lamps Flash

You said you disconnected the battery, and one would think that would clear a fault, but here is the code clearing procedure.
Clearing Diagnostic Trouble Codes - NV 243 (Electric Shift)

Turn ignition switch Off.
Remove T-case 20 amp fuse.
Wait a minimum of two minutes and 30 seconds, then replace fuse.
Cycle ignition switch On and Off 5 times.

Thats good to hear, sorry it took so long for a reply. Glad it was resolved.

Attached is a chart for possible causes of 4WD not engaging.

What is the transfer case model identification?

The transfer case switch is located on left frot of transfer case.

Here are the diagnostic procedures.

4WD Will Not Engage

1. Test power to transfer case switch. With ignition on, connect test light to ground and backprobe Brown wire terminal at transfer case switch connector. Test light should light. If so, proceed to next step. If not, inspect 25-amp 4WD fuse in fuse block. If fuse is okay, attach test light to ground and backprobe Pink/White terminal at convenience center. Test light should light. If so, repair open in Brown wire between convenience center and transfer case switch. If not, repair open in Pink/White wire between convenience center and 4WD fuse in fuse block.

2. Test transfer case switch. With transfer case shift selector in 4WD position and ignition on, attach test light to ground and backprobe Light Blue wire terminal at transfer case switch. Test light should light. If so, proceed to next step. If not, replace transfer case switch.

NOTE: Remainder of transfer case electronic testing and diagnosis is performed with transfer case gear selector in 4WD position and ignition on.

3. Test front axle solenoid power circuit. Attach test light to ground and backprobe Light Blue wire terminal of disconnected front axle solenoid. Test light should light. If so, proceed to next step. If not, repair open in Light Blue wire between front axle solenoid and transfer case switch.

4. Test front axle solenoid. Attach test light between Light Blue wire terminal and Black wire terminal of connected front axle solenoid. If test light lights, replace front axle solenoid and proceed to next step. If test light does not light, repair open in Black wire between front axle solenoid and ground. If no opens in circuit are found, replace transfer case relay.

Lee, common problem with the CPI engines is th efuel pressure regulator blowing out. It is located under the upper plenum on the intake manifold. Not sure if the reg is serviceable seperatly on the 95's, might have to get the whole injector "spider". When the regulator blows, it dumps raw fuel down into the engine. Hard starting and poor mileage are good indicators. Test the fuel pressure as well to be sure it is within spec, If the reg is blown when you check fuel press. Then it may be at the higher end of spec because the reg thinks that there is low vacuum like on hard acceleration