4WD LIGHT STAYS ON!
 

Hi guys, if I put my truck in 4HI, the 4WD light comes on. But if I put it
in low range, only once in a while will the low range light come on, and it won't shift through the gears in low range when the low range light isn't
on, it just stays in first gear. Then when I put it back in 2WD, the 4WD light will stay on sometimes for more than a day. Any suggestions?

sounds like the actutor on the tcase isnt properly engaging try looking under the truck at the end of the stick where the pivot arm is and see if all the bolts on the bracket are in good working order sometimes they manage to snap or come out and that can allow the bracket to turn slightly and thus when you shift ranges the bracket may move slightly and the connecting rod may not completely shift the range, and the indicator is seeing that it isnt completely shifted.

The PCM uses the same wire that turns on the light to adjust the shift points on the transmission. If the light isn't coming on, the shift points will stay at the same road speed.

is that only for the trucks with the electronic shift? i have the manual shift 4x4 ,my 4wd or low light never come on and my truck shifts just fine. or do you think maybe a light in the dash is bad

A bulb is going bad or the switch in the t-case is sticking...I'll bet it's the latter.

The switch is next to the rubber hose vent line coming off the t-case.

Hey Cuda, about that switch, does it thread out, or do you have to split the tcase?

Have same problem (no 4WD light or lite stays on) manual hubs/manual shift 4WD works fine just no idiot lite so I have not bothered to look more closely ,,,,,,,,,,,, could this be a bigger problem than just a lite to tell what range the truck is in????????

No need to split the case, it's screwed in, be sure to check the aluminum washer. A new switch should come with it.

Ok, so I pulled out the indicator switch, and the ball would stick in the down position when I pushed it in. And since it's a dealer part only and no dealer within 40 miles had one, I decided to try fixing mine. I filed the end of a
paperclip down to make a tapered flat point, I pushed in the ball as far as it would go, stuck the filed end of the paperclip along side the ball and bent the clip around the switch body to hold the ball down. Used my dremel with a diamond bit to carefully remove the lip holding the ball in. Removed the ball, plunger, and spring. I had to lightly grind the plastic cup/guide until the contact tit would move freely inside of it. I put it back together, lightly peened the end to hold the ball in. It works perfectly!

If the automatic transmission will shift out of 1st gear when in low range, the switch on the transfer case is working.

bringing this back to the top for Matt to see.

Thanks... I'll try taking it out and seeing what I can find.

hey fellas im a frequent flyer on the 73-79 side, haveing some simular troubles with my 97 auto 4wd, auto locking, hubs, 7.3
I had to use 4wd to pull a boat out this weekend and now in the am the low range light stays on for 2.5 miles thus not allowing the trans to shift from 1st to 2nd its a shift from 1st to I assume final drive. I can drive the truck by manualy shifting on the colum and it goes thru all the gears fine.
After the first 2.5 miles and it is "warmed up" and the light goes out the truck will shift fine all day long.
Any suggestions?

bump:confused:

Have you crawled under the truck and looked at the linkage? Check to be sure that the bolts are good and tight on the transfer case shift linkage and that the bracket is not moving around. You can also pull the switch out of the transfer case (near the rubber breather line) and make sure it moves freely.

I'm not really sure why it would only act up when the truck is cold though. That is a bit strange.