# 4wd light not functioning



## wildbl1500

So, I come home after last night's festivities i was using 4wd on and off in the city and then I went to 2wd on the dry highway back home. The 4wd light was working just fine. Once I pulled onto my road I needed 4wd again so I pull the lever, hear the quiet clunk, but no light. Playing around with it a little more while putting the plow on in preparation for the increasing snowfall it IS going into 4wd, but no light.

Any ideas? Keep in mind it is snowing and I have no garage.


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## drivewaydoctor

I have this exact same problem on my Dodge Ram 1500. If I find the solution I will let you know.


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## newhere

yeah your 4wd shift mod is on its way out the door. i have great news though, the oem use to be the only way to buy them for over $400!!!!! but now you can get one on ebay for 70-80 bucks! 

look down on the passenger side of your front axle housing and you will see a little metal circle/canister with two vacuum line running to it. That is what shifts the fork and also what makes the light come on. if you pull off the line closest to the passenger wheel i bet the light will come on and then just put the hose back on (if you really want to see the light) 

The problem is the slide inside that modual, when it is engaged in 4wd it slides the fork over and that in turn slides a coupler/sleeve over both from drive shafts to lock them in gear. at the same time when the shaft slides over it hits the end of the housing and makes a complete circuit and in turn lights up the 4wd light. 

you can take the modual off (only four little bolts hold it on) and use your hand to work the shaft back and fourth and spray some fluid film on it and that will get your light working again but i cant say for how long??? you are going to start to notice that it will take longer to engage and disengage 4wd until ultimately it will not engage. 

IN CASE OF A EMERGENCY and you need your 4wd take that outside line off and pull forward slow then pop it into neutral and rev the engine a little bit while you are still rolling. that will get it into 4wd and then go put the line back on.

If it wont come out of 4wd then take the opposite line off and do the same thing. 

when you see a dodge during a event with a bed full of snow because he cant get it into 4wd do him a favor and go teach him how to take that line off.


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## newhere

this is what you need

http://cgi.ebay.com/ebaymotors/1997...ptZMotorsQ5fCarQ5fTruckQ5fPartsQ5fAccessories


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## wildbl1500

Thanks for the info. If the light comes on by removing the hose, does that mean 100% that is the shift module? I don't want to shell out $80 just to troubleshoot.

That application is only up to a 2000 model year, I have a 2005. Is it the same setup?


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## newhere

im not sure, i was just giving you a picture of what it was.

yes, for sure if you take the hose off and the light comes on then that says the shaft is not sliding far enough and needs to be replaced or cleaned. if it still doesn't come on it could be all kinds of things like broken wires, bad plug, build up on the end of the shaft so its not metal to metal contact. take the controller right off and mess with it, you will figure out real quick how it works and what to clean. i would recommended you either pull the right tire up on a ramp or jack up that side so the oil will not come out of the axle.


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## wildbl1500

Just went out to look at it, as the snow has tappered off. First, the 4wd light is now on when I cranked up the truck... Second, I may be missing something, but I don't see the actuator anywhere on the axle.

Again, thanks for your help Newhere.


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## festerw

IIRC 02+ don't use the axle disconnect.


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## kshliapa

There is a switch on the transfer case that turns the light on/off.I belive from what you said that the 4wd still works, just the light doesnt go on or off.My 04 did the same thing started working/not working then stopped completely.I think the switch was like $20.00 and took about five minutes to replace.


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## Cover Guy

I Have A 05 That The Light Hasn't Worked For Two Years I Thank I mite Have To Fix Now


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## Green Grass

do you have electronic switch for 4x4 or is it a floor shifter? If you have the floor shifter as long as you pull it into 4x4 it is in 4x4. If the light does not come on it is just 4x4 switch mounted on the t-case that controls the light. On a 2005 2500 you do not have front axle disconnect that is pre 2003 and 1500 only.


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## stillen

kshliapa;940160 said:


> There is a switch on the transfer case that turns the light on/off.I belive from what you said that the 4wd still works, just the light doesnt go on or off.My 04 did the same thing started working/not working then stopped completely.I think the switch was like $20.00 and took about five minutes to replace.


Ditto, mine did the same.......... just a little switch up on top of the transfer case....... 30 minute job, 22 dollar part....


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## Evan528

My 4x4 light has not worked in a few years on my 03 3500. I have had the dealer look into it twice and both times they told me I have the wrong wiring harness....... thats funny since they were the only ones who have ever touched my truck exept for oil changes. I gave up on having it fixed....


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## wildbl1500

yes, I have the floor shifter. 4wd is still working fine- i haven't had the truck out of 4wd since Friday... and the light has stayed on. Anyone got a part# on the sensor?


I knew there'd be someone around to point me in the right direction.


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## newhere

Maybe pre 03 but def not 1500 only.


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## stonewellmark

Hey, check the bulb for the light first. Not to discredit anyone but often its the simplest things that go wrong.


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## wildbl1500

I'm taking my car to the dealer in the next few days so I'll get the sensor then. Thanks again guys!


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## ramper

I have a similar problem on my 02 Dakota. Is there a similar actuator?


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## Green Grass

ramper;952492 said:


> I have a similar problem on my 02 Dakota. Is there a similar actuator?


If it is Manual 4x4 then yes there will be a T-case switch


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## ramper

Sorry it is electric (switch on the dash). I had it into the dodge dealer and they worked (and charged for 2 hours) and it still how it was when I dropped it off.


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## Green Grass

ramper;952924 said:


> Sorry it is electric (switch on the dash). I had it into the dodge dealer and they worked (and charged for 2 hours) and it still how it was when I dropped it off.


take it back and tell them they did not fix it. They have come back policies.


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