Dashboard Lights and CDL Question

This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.

izzyandsue

izzyandsue

Izzy
SILVER Star
10 Year
Joined
Oct 31, 2014
Threads
119
Messages
6,871
Location
Charlotte, NC
Website
www.tactegra.com
Gang,
2 topics in one posting. First, had my dashboard off to get to the CDL light not coming on (after going 4L on this past trail work day), swapped the light with the ABS light which I know is good, put it back together and still no light on CDL when 4L selected. I know the CDL engages, I can feel it as the truck drives differently. Ordered a new switch ($17 from Amazon) just in case that's it and will install this weekend. Any other suggestions? I can feel the "grunt" and change from 4H to 4L, but no light.

Question 2, how do I get to the "D" light bulb? When I had the unit out, there is a white piece covering where the PRNDL lights are, and it has a printed wire board wrapping it, and I wasn't sure if I have to remove that first? Don't want to break the thing. Or just push the plastic detents and pull? Anyone done this before, appreciate your knowledge.
 
On the first topic, do your diff locks engage? Unless someone has done some fancy wiring, the diff locks will not engage unless the center diff is engaged. There is a sure-fire way to verify that the CDL is engaging.

1.) Engage the CDL. When you are sure it is engaged, goto step 2.
2.) Chock the one of the rear wheels securely, then shut down the engine, leaving the transmission in neutral. Turn the ignition back to on.
3.) Jack one of the front tires up off the ground so you can attempt to spin the tire.
4.) Try to spin the tire (this will take some force). If the CDL is in fact locking, you will not be able to turn the tire without moving the truck ;) If the tire does spin, the CDL is not locking (NOTE, you must have the transmission in neutral since by turning the wheel in the air, you are working backwards through the drive train and the transmission in park will make you think the CDL is locked).

HTH
 
Having the D go out is an upgrade. Trust me and the other happy campers here on Mud
 
I also wanted to get the PWR light on to know when the Flux Capacitor is activated! I measure power to and from the switch, so thinking is the bulb.

Sam, did the test as you outlined, front wheel spins. So I take it its not locking the CDL? I have a new switch coming, hope that is it, will change it this weekend. Any other parts I should look for? Thanks again.
 
Can you hear the actuator for the CDL (it is easily heard when the engine is not running)? If the PO did not lock the CDL often, it may just take some work to loosen up. Also, check the fuses to make sure the system is getting power and the wiring behind the dash to make sure the blank/jumper in the harness is still in place (it could be missing if the PO installed a CDL switch then removed it).

Cross your fingers that it is something simple as the actuator is a real bear to get to.
 
Will do, I have been wheeling a few times, everything has worked perfectly until this weekend (CDL and lockers). PO had it pretty much stock and I didn't mess with with adding CDL switch. Didnt know it had dedicated fuse, go to check that out. Read enough about the sensor so that's why I ordered it, cheap fix if thats it.

I did installed sliders, maybe truck got scared?
 
30 amp fuse is good. The front and rear locker lights do come one when ignition one, but the CDL light does not. I read elsewhere that was typical of the sensor going bad, needing cleaning or replacement. If not, will add to the list of oh-s***s.

I can hear the click sound from solenoid or whatever it is in the footwell when I pull the lever to 4Low. But can't hear anything else, like the whir of the motor.
 
Last edited:
I just read another post by Toolrus, looks like worse case I have to remove, clean, reinstall actuator. Crap. Or get a used one and replaced it. There seems to be also a 4L sensor that detects the selection of 4L, then signals the motor, then the CDL sensor comes into play after motor engages.
 
Thanks John. I thought I read everything, but there is always more. So the CDL is not locking as per the test and wheel turns free, fuse is good, light bulb is good. I will switch sensors tomorrow or Saturday, not sure what that will do. Next is to "tap" motor with rubber mallet, see if it engages. Will let you know.
 
I'd have to go back to the wiring diagram, but you can always bypass the sensors with a jumper wire(s). However, you do need to know if the sensors are normally open or normally closed to bypass them correctly .... I do not recall their operation.

Sine you had the dash apart, I would suggest you look at the harness behind the dash as well. On later model trucks, there is a jumper plug in the harness. If this is missing, the CDL will not engage period since it mimics the CDL switch in the "on" position. When you add the CDL switch, you remove this jumper and replace it with the switch ....

The Sleeoffroad site has a good write up on this in the tech section.
 
Jump the sensor that is in the transfercase. Normally if sensor is bad the light just blink. In your case it doesnt come on at all if i understood right.
 
Sam, it stopped working before I had the dash apart, I wanted to check the light bulb first. It was working perfectly until Saturday. I dont have the CDL switch on dashboard.

Rafael, correct, no light, it won't even turn on when ignition on like the other dashboard warning lights. The only difference between last time I used it and Saturday is I installed the winch. Depending on rain today I may get under it and see if tapping motor may free it up? There seems to be a CDL sensor that goes bad, but also a 4Low sensor. They look to be about the same. My understanding is the 4Low sends signal to CDL motor to engage, The sensor is normally open, so when shaft pushes ball up, it makes contact to let system know 4Low is called for. I will try to find both sensors and jump each, see if it works.

It can be confusing as the 1996 FSM that I have does not show a 4Low sensor, only CDL sensor. The 4Low I found on this thread https://forum.ih8mud.com/threads/cdl-actuator-fun.68015/page-3.
 
Shoot me your email via PM. I have a 1996 EWD that may help
 
I FOUND IT!!! Amazing, I was feeling dejected, but now there is a solution. So, got under the CD area this afternoon after mounting the mike for the new hands free radio. Went in with variety of hammers and a flashlight, so I could tap things until it worked. I found this!

image.webp


This wire loom is connecting in the area where the CDL sensor is, and do you see the broken frayed wire? Looks like green with yellow stripe. Anyway, I was able to tget the wires to touch and bang, everything works. So at least I know where it is. Why would that wire be out of the loom and why did it fray? I dont know, but it's right on that lever. Not sure how to connect yet, but at least it worked.

image.webp
 
Last edited:
John,
looked and read a few threads (more than a few),but didn't find anything yet. Will read others tomorrow. Now I have a spare CDL sensor...

Sam sent me a few diagrams earlier, and I think the wire was frayed, and it didn't look cut, was the green yellow one next to Junction Connection. I am not good at reading these, but it looks like it comes from the Relay (I hear it clicking well) and goes to the CDL control motor. I hope that's all it was, will get it reconnected and add some armor around it to prevent any issues in future.

upload_2015-3-26_22-5-17.webp
 
Last edited:
having the D light not working was a good thing for me....makes it really noticeable when its in 2....which I needed noticing a few times
 
Thanks all. But if I still want to change the bulbs, at least the PWR one, how do I get to it? I can particular about those things, like last weekend, washed, compounded, polished, and waxed truck. Didn't do clay bar, yet... Why, I want the paint to stay as good as it is. Will it get dirty? I hope so, but like a good rifle, I clean it so I know it will be in perfect order when I need it. I know, odd duck, but imprinted that way long ago.
 
You have a white panel insert the has four tabs. Pull that out and you will find the minibulbs on the side of that insert.
 
You must log in or register to reply here.

Share this page

Back
Top Bottom