[Brhatweed]

According to the FACTORY service manual the "blower resistor" (control module) is located nearest the firewall behind the blower motor itself and will have two connectors going to it one with two wires coming out to feed the motor itself and the other power in and data. The manual shows no relay for blower "HIGH" instead this is handled by the control module which is a digital PWM motor driver that is fed data from the BCM, there is no live connection between the dashboard blower speed control to the motor itself, everything is handled by the BCM.
Ive had problems with my blower motor in the past and it was a burned pin on the purple wire coming from the control module, this is a common problem with that module which is shared among most of the domestic made GM cars and trucks. Later modules have the wire soldered directly inside leaving only the 3-pin power/data connector. The thin purple/white wire should never be directly connected to +12V as it is only designed for digital data and will destroy the module.
Haynes, Chiltons and Clymer manuals are little more than a continuous stream of recycled half truths from previous editions. When I see the underhood detail of a Ford LTD used to describe a part on a late 80's Chevrolet truck I know its time for a factory print.

This is the other control module that plugs directly into the motor, there is an adapter plug & harness to convert from the 5-terminal to the 3-terminal.

 

[Brhatweed]

I will look at the schematic and post what I can when I get home.

 

[Brhatweed]

Here's what I have found so far; the HVAC blower motor supply is hot all times and is fed via 30A fuse located in the top box under the hood. No relays in the way and it's possible the wiring within the fuse panel is at fault, I've had problems with these before where the terminal deep inside would get hot enough to lose it spring and not hold on to the fuse blade itself. If you have test light and with a known good fuse in place ground the one end of the light to the battery - and touch the test end of the light to both sides of the 30A HVAC fuse top, it should light on both side of the test terminals. No light? Move the one end of the test light to the battery + and with the key ON touch the fuse with the test light again, it should light indicating the blower module is looking for current.
The damage to the fuse terminals isn't always obvious from the top so you might have to lift the fuse carrier from the strut tower and look at the wiring and terminals. The HVAC is a thick red and runs direct to the control module 3-pin (or 5-pin) connector. Check for power on the red terminal and if absent I'd suspect a break along the way.

 

[Brhatweed]

Rant all you want I'm right there with ya! I have done work as a technical writer in the past and nothing irks me more than inaccuracies in a service manual. We're all human and I get that but when the manual is written by the very ones who designed the product in the first place and the mistakes are left unchecked that is just beyond comprehension.
I spent the better part of my working career with Motorola doing 2-way radio, if anyone can make a convoluted mess it's the friendly folks at Technical Publications. A Micor base station for example has four separate manuals and those are broken down into sections for each of the cards/options and station installation plus the base instruction manual all the size of a medium size telephone directory. The Centracom Series-II instruction manual is over 5" thick and weighs 14 lbs, I used to carry over 50 of these types of manuals in my service truck. It was a Ford F250 ext cab long box 4X4 with a 300-six & 5-speed, with both 35 gal tanks full it weighed 6080 lbs on a CAT scale.