[firefighter327]

I have a 01 Ram 1500 4x4 and all of the sudden (after 3 days of ice and snow) the 4wd light started flashing and when I would let off the gas it would come back on. Vacuum leak right? Well I checked all the connections and found no leaks so I bypassed everything by running a new vac hose direct from the intake to the cad. All four tires spin but the 4wd light is off. I pulled the switch out and pushed the plunger with my thumb and on came the light. Any ideas on why the light won't come on normally?

 

[firefighter327]

Ok I just went to the store and the 4x4 wouldn't work at all axle or light . When i left the store I put it back into 4x4 and the axle is spinning but no light again.

 

[jackel440]

I would say it sounds like the switch.But you say it did not work the one trip.I would re check the vac. lines. and maybe the diagphram is going on the axle.might not be shifting the fork all the way over to push the plunger on the switch,but enough to make the collar engage the splines of the 2 shafts.
I had one not shift all the way over and the collar that engages the splines of both shafts moved back on the shaft from torque of the drivetrain causing the shaft that the shift fork is on to bend.

 

[firefighter327]

I am leaning towards the cad since I bypassed everything and went from the engine directly to the axle with a new vacuum hose and it did not make a difference. what did you do to fix yours?

 

[jackel440]

I did some creative engineering on mine.I would suggest getting a new cad or you could get one of those posi-lok conversions.

 

[INSANEBA]

I've been having some trouble out of mine lately. I got hung up in a ditch yesterday, and the front axle dis-engauged. It just popped out, and the light stayed on. I had to work it out in 2wd, sucked. Is the cad my problem? I did a body lift and thought maybe body twist might be throwing my linkage off a bit. Any help is appreciated, thanks. Oh, and wasnt trying to hi-jack this thread, just thought we might have the same problem...

 

[firefighter327]

Well I bought a new vacuum shift motor (cad) and presto it is fixed. The old one actuates really rough by hand and is full of gritty rust. I actuated the old one in my hand by hooking up a vac hose and it wasn,t going over far enough to trip the 4wd light switch and it was real slow. I reassembled it with the new part and did the same test and it is fast now and travels farther. I guess the combination of corrosion and the old stretched diaphram made it slow and kept it from engaging all the way.

The factory wanted $296 for the vacuum shift motor (cad) and I found a new one at a four wheel drive shop for 1/3 the price.

 

[INSANEBA]

Wow, I'm goint the posi lock route. I'm never gonna deal with this again, I do way too much weelin to take that chance...