Pushbutton 4WD Intermittent Failure

[AlohaOBS]

I’ve been having issues with my 4WD buttons. Vehicle is a non- autotrac 1996 RCSB with the 5.0/Auto. The orange led’s on the pushbutton selector for the 4x4 randomly stop displaying what mode the Transfer case is in. However the backlight still works for the buttons reguardless of whether or not the orange indicators are working. Throughout the day, it will randomly display the orange indicator lights, and they stay on for 30 mins or so before turning themselves back off. Every time they light up, the t-case will shift between 2/4hi/4lo perfectly fine. However when the lights go out, i am unable to shift the t-case until they decide to randomly come back on. I replaced the pushbuttons and the problem went away for a week, then the new buttons began to do the same thing: intermittent functionality, but the backlight works regardless. Is my TCCM Module under the dash going bad? The t-case shift motor works fine when the buttons are illuminated. Front diff actuator is only 14 months old... please help!!!

 

[RichLo]

I had a similar problem on a 2002 blazer, it drove me crazy until I accidentally found a vacuum line that was rubbing on the brake booster and had a small enough hole in it to make the front diff actuator not work but not big enough to make the engine run rough.

 

[RonRonnster]

I have the same problem in my '98. The transfer case indicator light usually lights up when I first start it, but after a few minutes it will go out. I think it's the actual switch going bad in my case. If I press on the plastic part that says "4X4" on it, the light will flicker and then come back on, and the buttons work. Acts like the internal circuit board in the switch is shorting out. I've been meaning to buy a new switch but haven't done so yet. Seems they are like $40 on Amazon.

https://www.amazon.com/dp/B00OZVP9J...olid=3DHY8BYF51OQ0&psc=0&ref_=lv_ov_lig_dp_it

 

[east302]

I have the same problem in my '98. The transfer case indicator light usually lights up when I first start it, but after a few minutes it will go out. I think it's the actual switch going bad in my case. If I press on the plastic part that says "4X4" on it, the light will flicker and then come back on, and the buttons work. Acts like the internal circuit board in the switch is shorting out. I've been meaning to buy a new switch but haven't done so yet. Seems they are like $40 on Amazon.

https://www.amazon.com/dp/B00OZVP9J...olid=3DHY8BYF51OQ0&psc=0&ref_=lv_ov_lig_dp_it

If you open the switch up, see if any of the solder connections are cracked. Reheat/repair them if so. Mine did that a while back, that fixed the issue.


Sent from my iPhone using Tapatalk

 

[JackE]

I have the same problem with the orange indicator lights working and not working as they please. My 4X4 does always work no matter what the indicator lights are doing. The pain of it is half the time I can't remember which button I pushed last. My T-case shifts in and out of 4X4 so quietly I can't usually tell if it's going in and out, but a punch of the throttle is verifying which mode I am in. Are you certain it isn't engaging even though the orange lights are not lighting up?

 

[AlohaOBS]

I have the same problem with the orange indicator lights working and not working as they please. My 4X4 does always work no matter what the indicator lights are doing. The pain of it is half the time I can't remember which button I pushed last. My T-case shifts in and out of 4X4 so quietly I can't usually tell if it's going in and out, but a punch of the throttle is verifying which mode I am in. Are you certain it isn't engaging even though the orange lights are not lighting up?

Im positive its not engaging on my truck unfortunatly. When the t-case engages, it can be felt and heard on my truck. I preciously replaced the buttons themselves because they would not light up at all and would not activate the t-case. Problem was fixed for a few months at most until the new buttons began to only work intermittently when the indicator lights decide to stay on. I’m going to replace the buttons one last time before i start having to dig into the problem deeper. Opened up the housing of the 4x4 buttons and there were no burnt solder points.

 

[alpinecrick]

Have you figured out what the problem is?

Seeing as how you've replaced the switch module, sounds like it's something else.

 

[AlohaOBS]

Update, the indicator lights stopped working all together, replaced the 4x4 buttons one more time and the lights are still not coming on. I’m lost now, going to look into testing/replacing the TCCM (Transfer case control module)

 

[JackE]

I had some pretty strange problems with my '99 last year. It ended up being the hot wire going to the front actuator motor had crossed paths with one of the ABS wires somewhere in the loom. I didn't find the culprit, I just ran a new wire from the firewall to the actuator and it solved my problem. I had a '97 with similar problems to what you are experiencing. It ended up being the encoder motor on the T-case. I figured that out by taking the motor off and using a crescent wrench to turn the shaft on the T-case to engage the 4X4. When I did this, I could hear the front actuator engaging, and the 4X4 worked. I actually just ran it that way for a while because of the cost of the encoder motor.

 

[AlohaOBS]

Out of nowhere the 4WD indicators on the buttons came on, it went back off a few minutes later, then came back on AGAIN. It’s gotta be an electrical problem, when the lights came back on the t-case worked flawlessly and 4wd engaged.

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