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Is it the noise starting at the 00:07 mark? It very well could be the motor bearings. I'm assuming there was otherwise no other inputs to the HVAC controls. Right? The audio is not the best.
You mentioned earlier that you were concerned with the motor maybe being damaged by the control module. I find that unlikely but then again the previous owner really did a hack-job on the blower-motor so it might be worth to change out the blower motor anyway for that reason alone. Combined with suspected bearing noise could tip the balance toward definitely getting a new blower-motor.
You could try taking the blower motor out first and then seeing if you can feel any friction from the bearings when you spin the squirrel-cage fan by hand.
But, compared to the cost of a new blower-motor control module, a fan is cheap, even the most expensive one from AC-Delco.
Yes, that is the sound, although that kind of vibrating/grindy sound in the video is there in real life too.
Got it today, but my ratchet does not fit around the radiator tank and I really don’t want to take that out if I can avoid it, so I will need to get another ratchet and try again.
I got a new ratchet and replaced the blower motor control unit and tested the system, my fan controls now work perfectly. 😎 I’m working on editing together a short how to video on it now just incase someone else doesn’t know. All I have to do now is splice the wire back together, but I’ll do that later on, need a new soldering iron too. Lol
FYI the correct tool is a stubby 1/4 inch ratchet with a short extension and a 7/32 socket. I dropped the third screw (the one that is difficult to get to, on the bottom) but it seems to stay still and work fine with just the two, I will probably replace it when I do the blower motor because I’ll need to take the radiator tank out anyway, but that’s in the future.
Now I can turn my attention fully to the air conditioner.
The old blower motor control unit coming out. The spot where the blower motor control unit goes. Debris seems to have found it’s way in. The bad blower motor control unit. Another view of the bad blower motor control unit.
Yep. Once that was replaced it started working normally, and no more need to connect the ground.
Air is still out, but my vent controls now seem to work fine.
Yes, now you can get to the AC. I did a (almost) full AC replacement last year. I was able to flush the evaporator but replaced everything else, including the condenser. The worst part of the job was having to drain and then remove the radiator. This is the write-up I did on it. https://blazerforum.com/forum/2nd-ge...ent-kit-97066/
I finished that video I mentioned, shorter than I’d like and maybe insultingly simple lol but I hope someone finds it useful. If nothing else it will be a record for me to find my mistake later. Lol
Alright, diagnosing my jimmy rn, basically animals got in the Eng bay and had their fun. Now after retracing all the wires etc, I have a slight issue with the HVAC and Blower Motor. Essentially I'm trying to figure out if I have an issue with, the blower motor, PWM, or if the issue is futher down. I can't find any info if there is a Relay for the PMW BoMo as the STD BoMo. You mentioned orange hot constant, however at what time does the ppl/wht wire sent current to communicate between the two. Im not getting any connection when the truck is running, the blower speed selector is on max (tried various methods ac on, int air, ext air, defrost and main) still no communication. Is there a step or something I missed? I don't have a Multimeter atm so using a continuity checker instead but there should be enough current to still turn the light on.
Last edited by stickandstones; 08-16-2022 at 12:07 AM.
08-03-2019, 06:44 PM
