In summary I agree with mmusicmans viewpoint it is absurd to have the AC compressor running constantly with recirc function. I like his solution of having a compressor cut off switch. He has had zero issues with the solution so I see no downsides to having that control. Hope you’re enjoying your wee...

Max AC doesn’t blow on the windshield

It takes less energy to heat dry air, yes. But it does not take less energy to run the AC compressor to dry (AND COOL) the air and then heat it, especially when running the compressor costs fuel and the coolant heat is wasted energy otherwise. Many other vehicles have the controls set up in the way ...

I am an engineer.

It is stupid that they did not make a separate recirc button from the Max AC setting. And engineers both do not always know what we’re doing and often are not actually in control of design/functionality decisions like that

Regarding the stock factory control: The first 3 settings are compressor ALWAYS ON .... Max, Normal, and Bi-Level. The next 3 setting are compressor ALWAYS OFF .... Top Vent, Heater Vent, and Bi-Level. The last setting Defrost, is compressor ALWAYS ON. This is great info. The way the van works is p...

Do you have the transmission that came with the 5.3 in the van or the one from the 4.3? The output tail bolt pattern is different.

The wiring might work the same but the vss and rear prop shaft sensor positions are reversed between the 4.3 and v8 application auto track 2. 136/236 layout: IMG_2932.png 246 layout: IMG_2931.gif Just use the Astro wiring harness w the 236, follow the PDF earlier in this thread, and if you’re using ...

The VSS and rear prop shaft sensors are reversed from 236 to 246. You also can’t bolt the 246 on the Astro van is what I’ve heard but I never actually tried it. There’s really no reason to use the entire 246 wiring harness, you just need to add wires for the encoder motor and switch. You can chop pi...

I figured out the image thing I am just dumb. Phpbb is just old school lol I am used to the new fangled bulletin board image upload dialog Here’s the wiring diagram for the Tahoe switch IMG_2888.jpeg The front prop spins freely at the same speed roughly as rear in 2wd mode with no driveshaft I am gu...

I got a junkyard TCCM today and put it in and tech2 showed rear prop shaft rpms right away and I drove all the way home with AWD enabled (no drive shaft in right now) w no svc awd light, so good to go I think I wired in the 03-06 Tahoe switch (the one with the long connectors, not the blue) last nig...

Update I found my issue. It was not wiring or a bad sensor, I believe it is faulty junkyard TCCM. The TCCM can not read speed from rear prop shaft sensor pins even when I swapped the working front speed shaft pins over. I am going to try the updated 12577412 TCCM which apparently has software and ha...

Update: I got a VXDiag VCX Nano to use with PCMHammer to flash my 0411 PCM for eFan mod and decided to try out the Tech2 function... tccm.png Replacing the sensor didn't work. Just verified I am not getting rear propshaft speed at the TCCM so time to ohm out the wire. This is actually great because ...

Not that anyone asked, but I put a new speed sensor into the rear propshaft and it's still giving me grief. Also tried swapping the front out in case it was just a speed mismatch issue. No dice Going to get the meter out and check the wiring as well as make sure I pinned everything correctly back in...

I finally got around to pulling the codes out of the TCCM. Using an obdlink LX and torque pro in raw terminal mode >19 d2 ff 00. 6CF11A594300114B C0300 "Rear Prop Shaft Circuit Malfunction" 6CF11A594374114D C0374 heat or general fault 6CF11A59A72511C9 B2725 switch fault 6CF11A59000093BB - ...

Update: I never swapped in the s10 axle tube w disconnect. After about 3 years the transfer case is binding in turns in 2hi. Never did get the AWD to work reliably. Maybe I did something wrong or got bad junkyard parts. I also didn’t really use the 4wd terribly often so I’d say most of the wear that...