97 suburban 4WD selector switch

[zebra308]

OK,
I did a search and couldn't find what I was looking for.
I have a strange problem with my "97 GMC K1500 Sub. I notice recently that the 2 WD and 4WD indicator lights on the dash switch weren't lit up at all. Truck drove normally in 2 WD so I didn't pay much attention to it. I just thought the light must have burned out.
We recently had snow so I wanted to put the truck in 4W hi. I went to switch it and both the 4hi and 4lo lights illuminated?? It took a while to get the truck in 4hi and I confirmed the 4WD is working on some packed snow. When the truck is in 4WD mode both 4hi and 4lo lights are on. When I went to switch it back it took several tries to finally get it into 2WD.
The dash light did not come on in 2WD. What the hell could it be?? The switch?

I know the 4WD hi is working but it doesn't want to engage without a lot of screwing with the switch The 4WD is working so, I know it's not the problem??
Anyone have a similar problem???

Thanks,
Will

[jnbascom]

From everything I have read, it sounds like it is the TCCM acting up. It is located behind the kick panel on the passenger side. If you take it to the dealer they can scan the codes for the TCCM. Since the lights aren't working correctly this would be my guess.

[zebra308]

Thank you I will do that when I get a chance. Fortunately, 2WD and 4WDhi work

[Stealth]

do you have any electrical mods that could be messing with the switch?

[zebra308]

do you have any electrical mods that could be messing with the switch?

I'm not sure? I have installed a set of Hella driving lights..but that was a while ago and the switch was working after the install??

I did have a problem with the ABS light coming on this summer. A local mechanic replaced the pass. side hub ring and the trans sensor. I realy didn't take notice if the light for the 2WD was on or off after the work was done.

It's relatively hard for me to see the switch..the gear selector lever covers it from my line of site when driving.
I did notice that a lot of the ground connections are corroded. Cound this just be a grounding problem?

[dptyrob]

I've noticed sometimes the lights in my selector buttons work and sometimes they don't, at least the one inside the 2wd button. Everything seems to work okay though, except I may have had some problems with the automatic setting not working in the snow a few days ago. As long as my manual 4WD selectors work I'm happy though. Now if only the lights for the frequency/station pre-set buttons on my stereo worked.....

[Stealth]

i would try filing down the connection and cleaning them up, because corrosion can do weird things to your electricals

[zebra308]

OK,
Here's the latest on this issue.

I was able to buy a selector switch( the one that's in the dash) for very little money on ebay. I changed the switch and the same thing happens. ( BTW..it's the switch with 2 buttons . one button for 2wd, and one botton to toggel between 4wd HI and 4wd Lo)

As soon as I turn the key, all of the lights on the switch flash one time. After that, nothing is lit up on 2 wd and both lights are lit up in 4wd Hi, 4wd lo when I switch to 4wd.?????
So it wasn't the switch.

How do I determine if it's the encoder motor on the transfer case or the module in the kick panel?
Thanks,

[emalma]

Wondering if you isolated the problem with the 4wd switch lights... I'm having the same problem with my '99 K1500. Lights flicker, but don't stay on.

[triple-4x4]

I have a 99 Suburban with the NP246 transfer case ( 4 button type with the auto setting ).
Sounds familiar. My 2WD indicator light would be off. I would press 2wd while engine was running and it would light up for a couple of days, then off again.

One day I decided to cycle it through the various modes. 4WD hi was difficult to engage. Then I tried 4WD lo. Then it was stuck. Ended up having to install a new shift motor on the Transfer Case.

If this happens to you, it is possible to take the shift motor off the TC. Then using an wrench, shift the TC back to 2WD hi. At least this gets it back on the road until you can repair, as the motor is a bit pricy from the dealer.