I took the truck out on our dirt road, put it in N and then shifted into 4H. I put it in Drive and took off. I have no idea if the front wheels were engaged or not, but it all went smoothly (the shifting and the driving) and there wasn't any clunks or grinding noises. I stopped, put it in N and shifted back into 2H then took off again. All went smoothly with this as well.

I stopped again, put it in N and shifted through 2H to 4L and then back again. No issues. When I would shift into 4H the light on an area of the dash would would light up. I never looked at this section of the dashboard before so when I did I noticed there was a black piece of tape over it. I pulled the tape off and saw that the ABS light was on. It seems to stay on so obviously that's why the previous owner put tape on it (see photo below).



Is this light suppose to be on all the time? It seems to be shifting into 4WD all right. So how do I truly test it out to make sure it's really working?

 

Put the truck up on four jackstands. Try your various 4wd settings, and see what turns.

With engine running, trans in park, t-case in 4wd, turning one front wheel should cause the other front wheel to turn in the opposite direction. if it doesn't, CAD is not engaging.

ABS light should test when you start the truck, then go off, and stay off. Do you have 4wal? Or just Rwal? (got front wheel speed sensors?)

 

I don't have any jack stands. I also don't know what 4wal or Rwal is.

 

I took some photos of what I believe are the vacuum hoses/lines you guys asked about.

 

Rwal = Rear wheel ABS

4wal = 4 wheel abs

Being a 97 I think you only have RWAL. You can verify by looking at your front brakes. For 4WAL there would be 2 lines going to the hub, 1 for brakes and 1 for the abs sensor.

Good pictures. Yes those are the VAC lines to the tcase and CAD on the axle.

It was mentioned previously and should also say in that first link before to test the vacuum. On the axle you can pull that dual grommet off. Start the truck and shift into 4H (this does not require tranny in N, just leave in Park). Go under and feel which side of the grommet is pulling vacuum, it at all. If you can't feel it, then that is one issue.

Put it back on and then check at the tcase for the same thing. If no vacuum there, then you have to work back up to the engine bay as that is where the vacuum is generated. I don't recall on 97, but that line I think is around on the passenger side of the intake manifold. A couple lines come together in a T. One line comes from firewall that's for HVAC.


Do you have any wood blocks or material that is suitable and stable enough for in place of jack stands? Do you have a jack.

Get yourself a Haynes Manual. Find the DIY/FAQ subforum here. There is a thread that contains link to download (free) the Factory Service Manual. There is also a thread for Parts Manual too.

 

I went to O'Reilly's and one of the kinds was nice enough to come out and show me where the ABS lines were. We determined it's 4wal, because there were two lines one going to each wheel. He told me to pull the plugs apart on the lines, clean them up and then put some kind of grease in the connectors (small packet was about a buck). I did this and started it up again, but the light still stays on.

Another guy told me to take the battery terminals off, clamp them together and leave them for about ten minutes. He says this clears all the settings or something in the truck. I clamped them back on and started it again and the light is still on so I'm still not sure what it could be.

I looked for that sub forum, but couldn't find any service manual links for my Dodge. Would you have a link to that?

 

Nevermind I found it. Just used Google and typed it in. Brought up the DIY/FAQ thread in your forum for 2nd Gen. RAMs. I'll start looking through it to try an find this stuff you guys are talking about.

 

Found the following info from the manual....

ABS RELAYS
Two relays are use on the ASB system. An ABS warning lamp relay is used to activate the amber ABS warning lamp. When the lamp is, lit the voltage at the CAB monitoring point will be 0 volts. The voltage at the monitoring point will be 12 volts when the CAB energizes the relay turning the ABS lamp off. The second relay is the ASB main (pump) relay. This relay is used to supply voltage to the ABS pump motor, Front Antilock Valve and Rear Wheel Antilock Valve. Both relays are located in the engine compartment in the Power Distribution Center.

ABS WARNING LAMP
The amber ABS warning lamp in located in the vehicle instrument cluster. The ABS warning lamp relay completes the circuit for the lamp by providing a ground. The CAB checks the warning lamp at the beginning of each ignition cycle by turning on the lamp for 3.4 seconds. The lamp is used to alert the driver if a malfunction in the ABS system has occurred by turning the lamp on steady.

DIAGNOSIS AND TESTING: ANTILOCK BRAKES
The ABS brake system performs several self-tests every time the ignition switch is turned on and the vehicle is driven. The CAB monitors the systems input and output circuits to verify the system is operating correctly. If the on board diagnostic system senses that a circuit is malfunctioning the system will set a trouble code in its memory. NOTE: The MDS or DRB III scan tool is used to diagnose the ABS system. For additional information refer to the Antilock Brake section in Group 8W. For test procedures refer to the Chassis Diagnostic Manual.

So there must be a circuit malfunction somewhere. I'm not sure what to do or how to diagnose this beyond what I've already done. Might have to just wait on that until I can find a mechanic to look at it. I don't see anything about CAD or those vacuum lines you guys are talking about.

 

Trying to figure out where these are. That's why I thought if I could find a visual schematic or something, then I could locate them.

No, I don't have anything like that.

 

The guy at O'Rielly's suggested I pull the vacuum hose off the drum behind the brake box and stick the end in a container of Seafoam. He said it would suck up the Seafoam and it would clear out all the vacuum lines. I had about half a can so I did that and the truck blew out a humongous cloud of smoke, belched a few times and kept running. I drove it around and down the highway for a way, letting it work all the stuff out of itself.

Can't really say what it improved, but obviously it cleaned a lot of stuff out. The ABS light is still on so I'm not sure what to do about that. Like I said I'll probably have to take it into the shop and have them check that out, because I've done everything I know how to do.