4x4 dash lite constantly blinking

[fordguy1948]

The 4x4 dash lite on my 1999 Exp blinks continuously. The vehicle was sitting in my driveway for 4 days while I was on vaction. Came home, started it up, began to drive and........there is was, blinking. I had the fluid changed in the transfer case thinking maybe that would help; to no avail. Can anyone tell me what this lite means? If it is attached to a sensor or sending unit, where is it located?

 

[wickman]

Have you tried cycling through all the positions, then back to 2WD?

 

[fordguy1948]

Yes, I tried that with no results. Thanks for responding.

 

[AvroAero]

Maybe the motor went on the transfer case, do you see it moving/making noise?

Does it switch over to 4wd then back to 2? I mean actually, you'll have to test it on grass or wet pavement.

 

[fordguy1948]

Yes, I have tested it several times. It always switches over to 4 wd high and into 4 wd low then back to 2 wd.... all seems to operate ok. When it is in 4wd, if I turn the wheels to make a rather sharp turn, there is a loud "thunk" sound....maybe 2 or 3 "thunks" if I continue the turn. I know that it is common on high mileage vehicles for there to be a "wobble" in the steering. This "thunk" seems to maybe be a little more. What do you think? Is it possible that the motor may be loose? I appreciate your input.

 

[AvroAero]

I have a 99 Expy and the thunk isn't normal. Although if your on a high traction surface you'll hear it struggling because its under pressure from the turn (in 4wd). A guy that worked with me had a jeep cherokee all time 4wd and he had the same problem of the thunk noise on turns. The mechanic changed the axles, rebuilt the driveshaft a few times, and then the axles again (think the dealer messed up the order on the first axle) and it went away. But it came back after a while.

Mind you the mechanic isn't the best. Do you have a computer reader? Check the code. I'd have a mechanic check the front end. The diff, or the axles are problemed I'd guess. The steering on mine is a little different than normal vehicles but I think its the speed sensative steering that gives it that feel.

Btw, your going into netural first before going into 4 low right? Otherwise its still in high. Prob not the problem, but you'll be able to know for sure its going into low.

 

[fordguy1948]

Hey, thanks for responding. My brother-in-law, who is a mechanic but lives 6 hrs away, suggested that it may be a CV joint. I'm planning to take the Expy to a local mechanic next week to have it put on the rack and do a little investigating.

I know to put the shift lever into N when shifting into 4 low. That seems to work just fine.

I still would like to know why the 4x4 light blinks at the dash and, if it is attached to a sensor, where is the sensor located? I don't have a code reader but I have been told that this light will not produce a code.

 

[99EB4x4]

isnt there 2 seperate motors on the transfer case? in Auto 4wheel it can apply a little power to the front or 50-50 front rear. but when in 4high and 4low its locked in 50-50 mode thats why it binds on high traction surfaces. so wouldnt there be a motor that operates the clucth and a seperate motor to switch from auto4x4 4high and 4low?

 

[Copper93]

The auto 4wheel works off an electro magnet and clutches. When in auto, it pre loads the clutches for a quicker response. I don't think there is a motor. When you started the truck after sitting did it crank right up or did it lug like the battery was weak? Cranking on a weak battery can cause similar problems. You can try pulling the battery for a minute and resetting the system.