Well to be honest I haven't had to go thru this process yet... so I'm not sure what you had to disconnect and what may've been disconnected by accident. Looking back through your posts I saw you asked about grounds and those grounds all come out of the main harness passing across your dash. I didn't trace back to see just what they all ran. There is no simple single schematic for these, you have to look sections. I just looked at harness routing diagrams and mentioned all the grounds that came out of it. I dunno if you have the manual HVAC system or automatic? (automatic has a rectangular box on the front of the heater box with the vacuum hoses going to it, manual has all the vacuum hoses going up to the ***** on the dash) Oh, and I'm not sure what you meant by "heater doesn't work" If you can't control hot/cold there's a possibility you missed another connector. You can see this thru the glovebox hole, small black connector 6 hole/3 wires pushes down into top right of heater box. I've seen that one overlooked before.

 

I have an auto HVAC. I know where the rect box is, but I am unsure of the what plugs right into the top of the heater box. I didn't see that one. I do have one connector that is on the drivers side by the brake that doesn't have a home. It has purple wires with a black connection head, but no idea where it goes. I posted a pic of it.

 

I spent some time trying to identify that one with the purple wires, I'm still stumped. On the top right of your heater box is the temperature actuator. It's about halfway back on the box. A black connector pushes straight down into into it. 3 wires in the connector, a black, lt. blue, and brown. If you look under the silver arm coming from the vacuum actuator you should see a harness in back of it going into the actuator, you'd see the brown wire (that's the edge facing you). If you forgot to plug that in you'll never control hot and cold, that why I wondered if that's what wasn't working on the heater. Also since you have automatic you might have to reinitialize the actuator anyhow. With the ignition off pull the RDO BATT fuse for 10 seconds, plug it back in then turn the truck on. Oh, and on the grounds, you only have the 2 wire one on the passenger side. I just noticed the 3 wire one under the big bulkhead connector is Envoy only.

 

Well, I took everything out and checked it over. Everything is connected, but still no luck. The A/C and heat do not work at all. The dash is still all funky with no gas gauge, but the daytime running lights are on all the time now. Windshield wipers don't work. I'm exhausted and I gotta work tomorrow night, so to heck with it.

 

Only good news I have is tuck that connector out of the way with the purple wires.... If you had a clutch, it'd plug into it. That connector I was talking about, arm comes out of the actuator going left - bends up - then keeps going left.... look above the arm right after the upper bend. You should see an electrical connector going down into the heater if you peer in there. I'd take a picture but I discovered my Iphone HATES low-light. Also if that RDO BATT in the dashboard fuseblock is blown that'll screw up your heater and your digital display on the dash. All I can say about your wipers is check the big connectors where they hook to the steering column.

 

Good to know about the clutch wires. Checked every fuse in the dash fuse box, not one blown. I also checked the grounding wires I could find while I had the dash out. I found two on the passenger side underneath the carpet and the foam padding. These were not touched, so they are still intact. If there are others behind the dash, they werent disturbed as I can't find them.

an update to what doesn't work; the seat warmers and the overhead display with temp, mileage, ect. Overhead display is on, but no info displayed.

 

Does anyone have specifics on the location of grounding wires? I am thinking my problem could be ground wire related.

 

If you cant figure out the factory locations or are just suspect of the factory ground wires... Simply run new ones in addition to the originals. Be sure to ground the body , frame and computer(s) all together.

 

Combining with your thread on your dash for the background. No need to open a new thread on the same problem.

 

With lots of prayer, problem solved. Found a wiring diagram, was the IGN fuse under the hood. Now everything is working fine. Amazing.