idea for someone who has the schematics and know-how

[Odlaw]

this question is for the 07 classic silverado but may apply to other year models.

I would like for the "4x4" light in the cluster to come on when I'm in 4 wheel drive - not the stupid yellow indicator that stays on all the time and moves down 1 inch next to the 4x4 button when in 4 wheel drive. I always forget I'm in 4x4 until I get moving on the highway and hear the front end spinning.

I'm guessing the green 4x4 indicator in the cluster is for manual tranny equipped trucks but was wondering if this could be done?

Smitty

 

[great white]

You could always "low tech it" by breaking into the switch lights and running a feed to the bulb (or led, whichever it is) in the cluster from the 4x4 switch light.

Just make sure you cut the traces in the cluster to the bulb/led if you do this to prevent sending current somewhere you don't want to or:

 

[Ed HD]

Wait. There's a 4x4 light in the cluster? I wanna see this!

 

[trouttrooper]

I did see somewhere once someone wrote up a "how to" for this very thing. Dammed if I can remember where I read it.

 

[Odlaw]

Wait. There's a 4x4 light in the cluster? I wanna see this!

Yeah, when I had my cluster out chasing the check engine light problem I was having, I saw the nice looking (green) icon of the drivetrain with the front wheels turned slightly. It's to the right of the glow plug indicator on my 07.

Glad to see I'm not the only one that thinks the stupid setup GM has now sucks. I'm used to seeing that little amber light on all the time and don't pay attention if it has moved down one inch. That is just poor design.

Smitty

 

[83GMCK2500]

I will sic Dave (88GMCTruck) on this, I'm sure he's game for figuring this out. I know I want him to.

 

[88gmctruck]

We tried this Devin, or do you not remember?

The light in the cluster is controlled by the class 2 data system. There is no direct connection to it in the plug for the cluster. On floor shift trucks, there is an input running from the transfercase & axle switch to a pin on the ECM to tell it that it is in 4wd. On electric shift trucks, the same pin is empty on the ECM and instead the transfercase shift control module uses it's inputs to control the 4wd system and shift, etc.

Now, I printed off all the wiring diagrams awhile back and tried hooking this pin up to 4wd signal from the front axle/t-case in Devin's truck. I couldn't get it to do anything what-so-ever and determined that the ECM must be programmed differently for floor shift trucks VS electronic shift trucks. I figured this since the ECM would be the link that would send the data signal to the cluster to turn the light on.

Pretty much, the only way I can figure to make this work is to break the circuit on the cluster itself, and wire the light in with the push button indicator.

Maybe someone should talk to one of the guys that programs ECMs and find out if there is a flag that can be turned on to enable this light, once the appropriate wiring was added.

 

[88gmctruck]

Oh yeah, and my 02 is a floor shift. Instead of the little symbol mine says "4wd" in the cluster.

 

[83GMCK2500]

oh yeah...we did attempt this didn't we?

 

[88gmctruck]

My palm, is hitting my face.

Dude, we spent like an entire afternoon tracking wires down and probing things with a multimeter. Wow Devin.

 

[Odlaw]

We tried this Devin, or do you not remember?

The light in the cluster is controlled by the class 2 data system. There is no direct connection to it in the plug for the cluster. On floor shift trucks, there is an input running from the transfercase & axle switch to a pin on the ECM to tell it that it is in 4wd. On electric shift trucks, the same pin is empty on the ECM and instead the transfercase shift control module uses it's inputs to control the 4wd system and shift, etc.

Now, I printed off all the wiring diagrams awhile back and tried hooking this pin up to 4wd signal from the front axle/t-case in Devin's truck. I couldn't get it to do anything what-so-ever and determined that the ECM must be programmed differently for floor shift trucks VS electronic shift trucks. I figured this since the ECM would be the link that would send the data signal to the cluster to turn the light on.

Pretty much, the only way I can figure to make this work is to break the circuit on the cluster itself, and wire the light in with the push button indicator.

Maybe someone should talk to one of the guys that programs ECMs and find out if there is a flag that can be turned on to enable this light, once the appropriate wiring was added.

Wow! you guys have tried everything. Thanks for the info. Yeah, i was wondering if it was going to require a hack into to push button indicator.....but hey, if that's what it takes. Maybe one of you can do a how-to on that??

Thanks again
Smitty

 

[88gmctruck]

I probably could, I'm pretty smashed for time right now however, and IDK if devin wants to set his up like that.