1994.5 - 1997 7.3L Power Stroke Diesel  
Old 11-21-2014, 11:40 AM
How-Tos on this Topic
Last edit by: IB Advertising
See related guides and technical advice from our community experts:

Browse all: 4WD Guides
Print Wikipost

4WD LIGHT STAYS ON!

Thread Tools
 
Search this Thread
 
  #1  
Old 12-16-2009, 12:44 PM
brad7.3's Avatar
brad7.3
brad7.3 is offline
Senior User
Thread Starter
Join Date: Jun 2006
Location: Gaylord, Michigan
Posts: 136
Likes: 0
Received 0 Likes on 0 Posts
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?
 

Last edited by brad7.3; 12-16-2009 at 06:13 PM. Reason: Better title and capitalized
  #2  
Old 12-16-2009, 07:47 PM
Oversize's Avatar
Oversize
Oversize is offline
Laughing Gas
Join Date: Feb 2009
Location: Denver CO
Posts: 919
Likes: 0
Received 0 Likes on 0 Posts
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.
 
  #3  
Old 12-16-2009, 11:56 PM
joe_13894's Avatar
joe_13894
joe_13894 is offline
Posting Guru
Join Date: Aug 2007
Location: The boonies by Dallas OR
Posts: 1,507
Likes: 0
Received 1 Like on 1 Post
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.
 
  #4  
Old 12-17-2009, 03:14 AM
Muktown's Avatar
Muktown
Muktown is offline
Posting Guru
Join Date: Jan 2006
Location: Elkhorn, WI
Posts: 1,605
Likes: 0
Received 1 Like on 1 Post
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
 
  #5  
Old 12-17-2009, 05:45 AM
Cuda_jim's Avatar
Cuda_jim
Cuda_jim is offline
Post Fiend
Join Date: Oct 2003
Location: MICHIGAN
Posts: 5,903
Likes: 0
Received 1 Like on 1 Post
Originally Posted by brad7.3
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?
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.
 
  #6  
Old 12-17-2009, 06:51 AM
brad7.3's Avatar
brad7.3
brad7.3 is offline
Senior User
Thread Starter
Join Date: Jun 2006
Location: Gaylord, Michigan
Posts: 136
Likes: 0
Received 0 Likes on 0 Posts
Hey Cuda, about that switch, does it thread out, or do you have to split the tcase?
 
  #7  
Old 12-17-2009, 07:27 AM
Jaaaaaaackman's Avatar
Jaaaaaaackman
Jaaaaaaackman is offline
More Turbo
Join Date: May 2006
Posts: 668
Received 1 Like on 1 Post
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????????
 
  #8  
Old 12-17-2009, 08:42 AM
Cuda_jim's Avatar
Cuda_jim
Cuda_jim is offline
Post Fiend
Join Date: Oct 2003
Location: MICHIGAN
Posts: 5,903
Likes: 0
Received 1 Like on 1 Post
Originally Posted by brad7.3
Hey Cuda, about that switch, does it thread out, or do you have to split the tcase?
No need to split the case, it's screwed in, be sure to check the aluminum washer. A new switch should come with it.
 
  #9  
Old 12-17-2009, 08:03 PM
brad7.3's Avatar
brad7.3
brad7.3 is offline
Senior User
Thread Starter
Join Date: Jun 2006
Location: Gaylord, Michigan
Posts: 136
Likes: 0
Received 0 Likes on 0 Posts
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!
 
  #10  
Old 12-18-2009, 12:57 AM
joe_13894's Avatar
joe_13894
joe_13894 is offline
Posting Guru
Join Date: Aug 2007
Location: The boonies by Dallas OR
Posts: 1,507
Likes: 0
Received 1 Like on 1 Post
Originally Posted by Muktown
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
If the automatic transmission will shift out of 1st gear when in low range, the switch on the transfer case is working.
 
  #11  
Old 02-16-2010, 12:08 PM
foxracing0934's Avatar
foxracing0934
foxracing0934 is offline
Posting Guru
Join Date: Mar 2008
Location: Billerica, MA
Posts: 1,669
Likes: 0
Received 0 Likes on 0 Posts
bringing this back to the top for Matt to see.
 
  #12  
Old 02-16-2010, 12:30 PM
MustangMatt96GT's Avatar
MustangMatt96GT
MustangMatt96GT is offline
Posting Guru
Join Date: Nov 2008
Location: Lakewood, Colorado
Posts: 1,138
Likes: 0
Received 0 Likes on 0 Posts
Thanks... I'll try taking it out and seeing what I can find.
 
  #13  
Old 08-01-2011, 01:19 PM
bigdaddys76's Avatar
bigdaddys76
bigdaddys76 is offline
Senior User
Join Date: Nov 2010
Location: Chesapeake Va.
Posts: 373
Likes: 0
Received 0 Likes on 0 Posts
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?
 
  #14  
Old 08-01-2011, 06:48 PM
bigdaddys76's Avatar
bigdaddys76
bigdaddys76 is offline
Senior User
Join Date: Nov 2010
Location: Chesapeake Va.
Posts: 373
Likes: 0
Received 0 Likes on 0 Posts
bump
 
  #15  
Old 08-02-2011, 06:44 AM
DIYMechanic's Avatar
DIYMechanic
DIYMechanic is offline
Post Fiend
Join Date: Dec 2010
Location: Orrville, Ohio
Posts: 10,121
Likes: 0
Received 2 Likes on 2 Posts
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.
 


Quick Reply: 4WD LIGHT STAYS ON!



All times are GMT -5. The time now is 09:19 AM.