2nd Gen Non-Engine/Transmission 4wd light needs new bulb

[dknoch]

The 4wd light on my 02 is not working. Sensor checkes good so I need to replace the light bulb. Problem is, the light is soldiered into the circut board. Has anybody else replaced a bulb this way and what size, where did you get it from. Is there any tricks to this or things to watch out for? Thanks for any advise.



Dan

 

[Joe Mc]

See if you can connect aligator clips or mini clips to an aux small lamp and test the circuit. It may not be the bulb - wow an 02 and the 4X lamp went already? If indeed it is the lamp and you can solder it out without damaging other componets or the board take the lamp to an electronics store (Radioshack?) and see if they can match it up for you. Please keep post going till you figure out - I've got a 99 and the lamp still works . . . at least last time I used 4X it did. . .

 

[Thomas]

• It's not a "light bulb". ​
• Hope that the problem is not in the instrument panel. ​

From the model year 2002 Factory Service Manual:​

The four-wheel drive indicator consists of a stencilled
cutout of the text “4WD” in the opaque layer of
the instrument cluster ... illuminated from behind by a
Light Emitting Diode (LED) soldered onto the instrument
cluster electronic circuit board. The four-wheel
drive indicator is serviced as a unit with the instrument
cluster...
This indicator is controlled by a transistor on
the instrument cluster circuit board based upon the
cluster programming...

 

[Joe Mc]

Congrats to Thomas for getting the correct answer. Way to go! Looks pretty complicated though, now this really makes me hope mine never goes out . . .



please report back when you giter-done

 

[MCummings]

Just to double check... Hold down the trip reset/odometer button with the Key off, then turn the ignition to KOEO and after 3 seconds or so, you will get an instrument panel test.





Merrick

 

[SSabick]

My 02 has the same problem, and also a seatbelt guy that stays on full time, and many other nit-picky things on the panel. Man this stinks, I just thought there was a switch gone bad or something.

 

[dknoch]

It Works!!! It Really, Really Works!!! At least for now!!!



I had some time this morning so I pulled out the instument cluster and took it apart. 1st the card board and then the back panel off the cluster, gauges just slide out. The 4WD LED had a slightly diffent look than the rest, maybe a little darker. Since I have a 6-speed truck, I unsoldered the OD off light and then the 4WD. Getting the new light in was a bit tricky since solder filled the hole, but I worked it back and forth and kept the heat on it. After, I took a small cutting wheel on a dremel to make sure the connections stayed seperate. Reassembled, put back in the truck and it works.



Thanks again for all the help!



P. S. The gauge test where you hold down the trip reset button when you turn on the ignition still doesn't work the 4WD light, it must be on a seperate circuit or something.

 

[Thomas]

... Since I have a 6-speed truck, I unsoldered the OD off light and then the 4WD. Getting the new light in...

Are you saying you swapped LED's?

 

[dknoch]

Yes! Is that a bad thing, I can't think of any problem with doing that. It is no different than having the OD off light burn out.

 

[Thomas]

Sounds good to me - like the O/D LED is a "spare" for the standard transmission crowd.

 

[Stark_Ent9802]

wow my 4x light is out also, but for the amount of time I use 4 wheel. I'd have to have a lot of spare time to tackle that job. and mine is an auto, so i would be out tring to find a replacement LED.

Thank Thomas for bringing this thread to my attention!

 

[SSolderitch]

I got a 01 with a 4x4 light out also. Another thing to look at in spring. Can some one measure the voltage at the led? Then would be able to find a replacement bulb.

 

[tgordon]

SS, a LED is not a light that just plugs in. To the best of my knowledge they are all one size, and then one uses differant resistors to use with 12v, 120v etc. Try looking here 21,000mcd 5mm White LED, Cree 7090 XR LEDs, Luxeon LEDs, 5mm LED Reflectors, LEDs by the piece and LEDs in bulk form are in stock. , or doing a search on the internet for LED. Starting to sound like they got some bad ones and installed them in the trucks. I wounder if my 97 has a LED or a bulb?

 

[MCummings]

P. S. The gauge test where you hold down the trip reset button when you turn on the ignition still doesn't work the 4WD light, it must be on a seperate circuit or something.

Oh, that sucks. Ignore my comment then.



Merrick

 

[SSolderitch]

yes, when led first hit they all ran 1. 75v, but as technology improved they now make high 5v ones... . also size . 5mm, or 1, 3 & 5m m, bi & tri colored..... Newark, digikey and the other catalogs will have them, and are cheap, you must know voltage. As your link shows the resister & led must be matched and we already have the circuit in the truck to drop the voltage. also polarity must be followed or they won't light.

 

[dknoch]

I replaced the 4wd light with the OD off light on mine. It worked fine for a while then the sensor on the transfer case went out. The sensor is only available from Dodge (i'm told) but is was only about 30 bucks or so. There are a few leds that can be replaced, I would guess they are the same as the ones that are soldered in. Good Luck!

Dan

 

[Stark_Ent9802]

did you replave the sensor? If you did can you explain where it is on the TC? and how hard is it to replace?

Thanks

 

[Moose Truck]

did you replave the sensor? If you did can you explain where it is on the TC? and how hard is it to replace?

Thanks

Which truck AJ? I was going to to see my friends band Friday night (@ the Frogpond in Stratford), But I can swing by the shop if you want to have me help you test it out. Moose

 

[Stark_Ent9802]

the 3500 moose. I don't think I'll be around on friday.

 

[dknoch]

On my 02 2500, if I remember correctly, it is on the passenger side. I think it is the only thing on the transfer case that has wires. It is a 2 wire plug and the sensor unscrews with a wrench. I used a cresent wrench on mine and it came out real easy. The sensor uses a small ball that moves in a pocket and that sends the signal. It is very easy to check resistance if you have a meter. Put the leads in the holes for the plug and push the ball in with your thumb. Note though that when it first started acting up, I think it still checked OK on the meter. Good luck, keep us posted.

Dan