Attention: TDR Forum Junkies 
I knew the heater core had a weep as I could smell it but it finally got to the point that the antifreeze started dripping out the HVAC box.
So, it was time to change the heater core.
I have changed heater cores on many vehicles over the past 45 years but I have to admit I was a little stunned when the manual said "remove the steering column and dashboard". Say What???
I immediately jumped on TDR to see if the knowledge base here had discovered a short cut and found 2 articles and a number of threads about how to just tilt the dash back, etc.
Great! And off I went.
But, alas, it was not to be. Here's how the days went.
Wednesday evening:
Pulled truck in, loosened steering, airbag controller and dash.
Tilted dash out far enough to access heater core.
Drained antifreeze, pulled heater hoses.
Unscrewed 3 screws holding core in place.
Cut heater core pipes with saw.
Removed heater core. (wow…this is going great!)
Oops. HVAC box has antifreeze and yuch in bottom.
Fashioned cleaning hose to shop vac and cleaned heater core pocket.
Crud. Can't get new heater core in. Will have to loosen HVAC from firewall.
Crud. Can't loosen HVAC from firewall as PCM mounting screws are corroded and one HVAC mounting bolt hides behind it.
Had enough for day.
Total time: 7 hours. (only counting 5 as there was socializing and work was casual)
Thursday evening:
Quartet practice. No work done.
Friday evening:
Within one hour realized that the dash was going to have to come out.
As long as I have to pull everything I best replace the A/C at the same time. Ordered parts.
Removed front seats and console. (a really great move. 14 bolts and you have all the work space in the world. )
Six electrical connections on the left side, one vacuum connection in the center and two electrical connections plus antenna on the right side and the dash is disconnected. Five screws across the top, two bolts at the middle bottome and one bolt at the bottom on each side and it swings down and comes out easy.
Spent the rest of the evening un-wiring 10 years worth of electronic gadgets and radios that had effectively stitched the dashboard to the cab.
Removed dash (actually easy when all the other wires are not there)
Called it a day.
Elapsed time: 6 hours
Saturday:
Off to pick up parts first thing.
Wife asked me to do a few things "as long as I was out" (happy wife, happy life. . )
Back on task at 11am.
A/C disconnected
PCM removed from firewall
HVAC out of truck and on bench.
Opened HVAC. Wow, am I glad i decided to go the long way. Dirty, filthy, stinky. I was breathing air that was pumped through this???
This is really plugged.
A/C evap was 50% blocked and had 2 inches of mulch stacked against it from all the decayed leaves and such. (screen installed in intake to stop this now)
Disassembled entire HVAC, cleaned, verified all doors good and functional.
Installed new A/C, closed HVAC box, installed heater core and again verified all doors function.
Installed HVAC in truck.
Installed new A/C condenser on front of truck. (Big difference from that moth eaten looking thing that was hanging there)
Connected A/C and heater hoses.
Called it a day.
Elapsed time: 14 hours (only counting 11. not counting 3 for parts and errands)
Sunday:
Replaced antifreeze.
Charged A/C
Steam cleaned carpet and seats.
Spent and hour cleaning up wiring on the back of the dash. Was able to clean up some wires from the 2DIN radio install.
Spent and hour cleaning up wiring on cab, behind dash.
Installed dash.
Verified electrial.
Installed drivers seat.
Started engine.
Test drive to parts store for a few odds and ends.
Wow! I have as much air flowing on low fan as I used to have on high fan!!!
A/C is more like an ice maker.
Heater is blowing flames.
Uh Oh... heater is still blowing flames. Even with control all the off.
Turn heater knob... no blend door servo movement.
Turned HVAC off. Returned home.
Parked. Called it a day.
Elapsed time: 12 hours
Monday evening:
Looked at electrical schematic.
Back of HVAC control has 3 electrical connectors and one vacuum connector.
Vacuum and 2 electrical were plugged in.
Guess what wasn't plugged in? (hint: blend door servo pot)
Plugged it in. Temperature control restored. (and the peasants rejoiced)
Installed remaining interior.
Done. (except all the gadgets and radios. But they are getting wired with disconnect plugs at the dash this time)
Elapsed time: 1 hour.
Total time: 35 hours
Result: Almost a new truck smell with great climate control again. No loose wires. Fresh start on installing "toys".
So, it was time to change the heater core.
I have changed heater cores on many vehicles over the past 45 years but I have to admit I was a little stunned when the manual said "remove the steering column and dashboard". Say What???
I immediately jumped on TDR to see if the knowledge base here had discovered a short cut and found 2 articles and a number of threads about how to just tilt the dash back, etc.
Great! And off I went.
But, alas, it was not to be. Here's how the days went.
Wednesday evening:
Pulled truck in, loosened steering, airbag controller and dash.
Tilted dash out far enough to access heater core.
Drained antifreeze, pulled heater hoses.
Unscrewed 3 screws holding core in place.
Cut heater core pipes with saw.
Removed heater core. (wow…this is going great!)
Oops. HVAC box has antifreeze and yuch in bottom.
Fashioned cleaning hose to shop vac and cleaned heater core pocket.
Crud. Can't get new heater core in. Will have to loosen HVAC from firewall.
Crud. Can't loosen HVAC from firewall as PCM mounting screws are corroded and one HVAC mounting bolt hides behind it.
Had enough for day.
Total time: 7 hours. (only counting 5 as there was socializing and work was casual)
Thursday evening:
Quartet practice. No work done.
Friday evening:
Within one hour realized that the dash was going to have to come out.
As long as I have to pull everything I best replace the A/C at the same time. Ordered parts.
Removed front seats and console. (a really great move. 14 bolts and you have all the work space in the world. )
Six electrical connections on the left side, one vacuum connection in the center and two electrical connections plus antenna on the right side and the dash is disconnected. Five screws across the top, two bolts at the middle bottome and one bolt at the bottom on each side and it swings down and comes out easy.
Spent the rest of the evening un-wiring 10 years worth of electronic gadgets and radios that had effectively stitched the dashboard to the cab.
Removed dash (actually easy when all the other wires are not there)
Called it a day.
Elapsed time: 6 hours
Saturday:
Off to pick up parts first thing.
Wife asked me to do a few things "as long as I was out" (happy wife, happy life. . )
Back on task at 11am.
A/C disconnected
PCM removed from firewall
HVAC out of truck and on bench.
Opened HVAC. Wow, am I glad i decided to go the long way. Dirty, filthy, stinky. I was breathing air that was pumped through this???
This is really plugged.
A/C evap was 50% blocked and had 2 inches of mulch stacked against it from all the decayed leaves and such. (screen installed in intake to stop this now)
Disassembled entire HVAC, cleaned, verified all doors good and functional.
Installed new A/C, closed HVAC box, installed heater core and again verified all doors function.
Installed HVAC in truck.
Installed new A/C condenser on front of truck. (Big difference from that moth eaten looking thing that was hanging there)
Connected A/C and heater hoses.
Called it a day.
Elapsed time: 14 hours (only counting 11. not counting 3 for parts and errands)
Sunday:
Replaced antifreeze.
Charged A/C
Steam cleaned carpet and seats.
Spent and hour cleaning up wiring on the back of the dash. Was able to clean up some wires from the 2DIN radio install.
Spent and hour cleaning up wiring on cab, behind dash.
Installed dash.
Verified electrial.
Installed drivers seat.
Started engine.
Test drive to parts store for a few odds and ends.
Wow! I have as much air flowing on low fan as I used to have on high fan!!!
A/C is more like an ice maker.
Heater is blowing flames.
Uh Oh... heater is still blowing flames. Even with control all the off.
Turn heater knob... no blend door servo movement.
Turned HVAC off. Returned home.
Parked. Called it a day.
Elapsed time: 12 hours
Monday evening:
Looked at electrical schematic.
Back of HVAC control has 3 electrical connectors and one vacuum connector.
Vacuum and 2 electrical were plugged in.
Guess what wasn't plugged in? (hint: blend door servo pot)
Plugged it in. Temperature control restored. (and the peasants rejoiced)
Installed remaining interior.
Done. (except all the gadgets and radios. But they are getting wired with disconnect plugs at the dash this time)
Elapsed time: 1 hour.
Total time: 35 hours
Result: Almost a new truck smell with great climate control again. No loose wires. Fresh start on installing "toys".
Now, add into that mix a sasquatch in the front floorboard, and I can relate..... I think a time or two I've removed the seats without unbolting them... . 
Always a good idea when you weigh in around 300lbs..... OH, and yes, your evap core was dirty, but ever removed one that looked like a sheep?!?!? God bless cotton farmers..... 
