Emergency blower motor question ALL INPUT APPRECIATED!

No blower motor in the roadie, replaced with one from the caddy, a known good one, and it was working great for a couple days. All of a sudden it just stopped working again. I wiggled the wires and it would half ass come on. Replaced all connections and now nothing. Took the motor out and put it directly to the battery, nothing, wiggled wires a little and it came to life with lots of power, cleaned the terminals and then installed it., turned on the heat: NOTHING!
Now the thing won't work on the battery, jump wires, anything

Any reason 2 motors would just die?
I figured at least on 12v direct it would work.
WTF is going on?

Can't drive around with no heat!!!

What kind of shape is the blower motor resistor in?

No idea it looks clean not all corroded. I plugged the blower back into the caddy and nothing it's FRIED!

Take a look at the terminals on the resister. I had two go bad on me recently... Didn't cause an issue like that but it's worth a look.

It's a bad blower motor. When you have to jiggle the wires, it's time for a new one (or a good used one). I've had to change a couple over the years.

Yes but I took the one from the Cadillac and tested it twice before installing. After being in the Buick 2 days it's junk.
I also noticed the purple and black wires going into the blower motor were strange,
I cut them and stripped back the plastic and the copper wire inside is blackish in color, like all the way up the wire. Any idea on that? Related?

My FSM are at work. Ill take a look tomorrow.

One of the wires in my 9C1 was blackish no matter how far I stripped it, I wouldn't worry about that. Check the terminals on the blower control module like Tim said, they break off a lot (had 3 die on me this year). The module is to the left of the blower motor. You can borrow the one out of the caddy to test it.

One of the terminals (the orange one) was previously cut and attached to a female crimp connector.
Still not the issue I'm looking for... I know WHY I have no heat, the blower motor is JUNK! I know this because I plugged it back into the caddys HVAC and got nothing! It was working mint 2 days ago, the question I'm asking is WHAT is eating my blower motors? I've been through 2 in the past week.

Is there a common thing that happens electrically? Like say resistor is bad or a relay is bad and it cooks the motor?
I've had a slight plastic burning smell on and off with the car for a month, but I haven't found anything melted anywhere!
I'm almost done putting the caddy back to stock so I'm not in a dire need to start pulling the dash apart, put if it's something that won't cost me anything I might try and fix it. I wanna pull this whole HVAC system out and stuff it in my 79 pickup. So if there is something severly wrong eventually it'll have to be fixed.

Could be the resistor. The resistor in my caddy is screwed right now. It keeps the blower motor running on high car on or off hvac on or off. I have to pull the fuse to shut it off.

Power goes to the blower motor via the Blower Motor Control Modual which I would assume is the "resistor".


https://2img.net/r/ihimizer/img820/5448/004xxqg.jpg

Diagnostic steps

https://2img.net/r/ihimg/a/img703/6776/005izv.jpg

https://2img.net/r/ihimg/a/img820/5448/004xxqg.jpg

I have power to the blower, test light lights when any buttons are pressed on the climate control that call for fan.
Originally the cars blower was working but making a loud humming noise, from July to now I just lived with it thinking it was just stuff in the cage (which it was). Then last week as I was driving I started smelling a burnt plastic smell and the fan (which was on high the entire time) progressively got weaker and weaker as I drove to work (45 min ride). By the time I got there it wasn't blowing at all,
Got home and replaced with the cadillac's blower tested it outside the caddy first, almost took my fingers off! Loads of power, installed it and ran it two day and no issues (but seemed to blow a little less than when in the caddy)
Then yesterday it did the same thing, started good and then on a 25 minute trip progressively got weaker and weaker until it died.
Plugged it into the caddy when I got back home and its dead.
Which leads me to believe Its something inside the wagon that's destroying the blower motor.
What I have no idea!

If you need to know where any circuts or grounds are let me know