[hatzie]

That's a standard ISO280 SPDT 40Amp sealed base relay. The GM parts catalog doesn't call for any relay in the wiring to the blower. This means it's likely integrated into some other component.

Haynes can be good sometimes and really really bad at times. The electrical in the Haynes manuals tends to leave a lot to be desired. When there are several changes over the production run they only provide the most common diagrams or the ones they can find and claim it covers the lot.
Mitchell has problems as well. I've found problems in the GM manuals too and penciled notes into my copies.

The aftermarket parts guys can be extremely frustrating the same way.

The 2000-2003 Impala shown in that Haynes manual wiring diagram has a resistor pak and relay integrated together in one package just like that Haynes manual shows. The blower fan plugs into a two wire pigtail dangling off the resistor pak and the HVAC harness plugs into the resistor pak on those vehicles.


The GM parts catalog calls for a different resistor pak on the 2004 & 2005 GEN VII Impala. This pak is the same part as I have in my 2009 Gen VIII. It only has one connection to the harness and no connection to the blower motor.

2004-2016 GM Heating and Air Conditioning Blower Control Module 22754990 GM | GMPartsDirect.com

2004-2016 GM part # 22754990 - Heating and Air Conditioning Blower Control Module

www.gmpartsdirect.com

If it's already real winter in Montana you definitely want cab heat.

 

[hatzie]

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.

I'm going to rant a bit. Not because it makes one bit of difference, but it makes me feel better.

🤬🤬🤬🤬

I haven't seen a Ford LTD in an aftermarket GM repair manual but I've seen a watercooled front engine Datsun 210 underhood picture in a Chilton air cooled rear engine VW 412 manual. That was back in the 1970's when some of them actually tried to do a good job.
Modern aftermarket wiring diagrams are better than a poke in the eye with a sharp stick, but only marginally. Even the ones you pay for like Mitchell leave a lot to be desired.
I have found several problems for which I penciled notes on into the margins of my paper OEM GM manuals for my 2000 T400 Sierra, 09 Impala, and 2005 T800 Silverado. The eleven volume 2005 CK truck manuals were $456 Yankee bucks. I'm less than ecstatic with the issues I've found in them and the lack of response when I attempted to bring the errors to their attention.

Nissan/Datsun, Toyota, Fuji/Subaru, Ford, Chrysler, BMW, VAG Gruppe, Mercedes... all have minor and major issues with the new and old manuals in manuals I've collected over the last 48 years or so.
IH, White, Oliver, Komatsu, Bobcat, Gehl, Caterpillar, ... industrial and farm equipment manuals seem to be a lot better but mine are for my own older equipment. John Deere was never great IMHO. No doubt they all suffer from the same cancer I'm seeing in the automotive industry. If I had new manuals for new equipment I'd likely find the same lack of care and attention to detail.