The 4 wheel drive in my truck has been a pain in the a** since I bought the truck new. I have a 2000 F250 Super Duty Crew Cab short box. I have had to replace the hubs (a couple times) and now the switch on the dash doesnt light up and it wont engage. I have talked to a few "parts" guys and they seem to think its the solenoid not the switch. Has anyone else had "issues" with the 4 wheel drive around the same year as mine??? Does anyone have any suggestions? Hubby says by a chevy next time....ugh!!! Thanks for any feed back.
I can't necessarily comment on the 2000 year being a particular problem. The stock hubs are a little to be desired and if they have undergone excessive use and abuse then you should replace with quality Warn units at some point. If the light doesn't come on first check your fuse and relay for that circuit. If the fuse is blown it could be a faulty solenoid or fatigued (blown fuse). If the fuse checks out ok replace the relay with one from another circuit (making sure it's the same type) to eliminate "it". If everthing else checks out ok i would replace the solenoid. I think there about $50 or so. If the Motor was bad you would typically have prior experiences such as improper engagement,noise etc..). Some one else may chime in on any circuit particulars. Wait till the hubby has a problem and then tell him he should have bought a Ford. If he still gives you flax, i'll come pick you up. LOL
The Vacuum Pulse Lock solenoid is responsible for applying a vacuum pulse to the front hubs to lock and unlock them. This only happens after the transfer case shifts into 4wd. If the transfer case isn't shifting, then the solenoid is not the problem.
The first thing you need to do is make sure the 4x4 indicator light is working. I believe in 2000 you have the electronic instrument cluster, so do this test first.
With the key off, press the trip reset button, hold it down and turn the key to ON. Do not start. Hold the button down until "test" appears in the odometer display, then release the button. Press the button again. The gauges should all sweep to the top and back down. Press the button again and all of the indicator lights should come on and stay on. Check to make sure the 4x4 indicator is working. At this point you can turn the key back to off. There are more things that can be done with this test but none of them apply to what you need. You can search on "HEC cluster" for more details on this test.
So, if the test above indicates the 4x4 light is working, this means your transfer case is not shifting. The first thing to check here is fuses. Check everything that may be related to the 4WD module, General Equipment module, or just check them all. Don't check them visually, remove them and check them with a meter for continuity. Fuses can be blown but not appear blown. A service manual could be beneficial here, as it would help you pinpoint which fuses to check. I have a 2004 manual though, and I'm sure the fuses are different.
The most common reason beyond fuses for the transfer case to not shift is the gear motor relays either being defective or having corroded contacts. The relays are in a box, under the hood on the passenger side towards the rear. They are the only two relays in the box and they are identical in appearance. There may be other boxes with relays in them, but you are looking for the box with two identical relays. The most common test here is to swap the two relays positions. One relay moves the shift motor from 2wd, to 4WH to 4WL. The other relay moves the motor the other direction, from 4WL, to 4WH to 2WD. If you swap the relays and you can now get into 4WD and not back out, you know it was one of the relays and the suggestion is usually to replace both of them. Also check the relay contacts for corrosion and the wiring to the box for fraying or broken wires.
If you get no joy from the relays then you are pretty much left with the gear motor encoder assembly on the transfer case, or in very rare cases the computer module responsible for 4WD operations (I believe it is the GEM module on the 2000 model year). I've read of a few cases here where the gear motor has gone out, but it is far more common for one of the above to be the problem. If you get this far, it might be professional time. You can test the motor by applying voltage to it, but you have to know where to apply the voltage and I don't have diagrams for a 2000 to help you with that.
I have a 2000 F350 and it does NOT have an electronic instrument cluster, so some of those tests are not going to work for her. I use my 4X4 frequently and have never had a serious problem with the hubs locking/unlocking. The only thing that I have done is replace the vacuum lines while servicing the brakes. I still have the original hubs and they are still working fine. 105,000 miles.
Thank you all for the responses!!! OK I have checked the fuses and they are all good. I have looked and looked for the box on the passenger side with the 2 identical relays in it and I cant find it. Have looked at the transfer case also and the wiring is plugged in there. My first set of hubs replaced were replaced under warranty, then I had to do it also. I dont have the electronic dash so I cant try that suggestion but thank you! Waiting to hear from you guys and thanks again for your help!! MsBehavin
I found that one (top is a pain in the a** to get back on!!!). There is only one relay in there. There is a spot for another one though. Could I use a relay from another area in the empty spot to try it out?? By the sounds of it I am perhaps missing a relay???