DDuncan51
New member
Coming home from a recent trip, the HVAC blower motor started screeching. It's always had a ticking when set to low, no bother, I just didn't run it on low. So I replaced the blower motor. I have both a Haynes and a Chilton Repair manual that I used to get me pointed in the general direction. Although it appears to me that every GMC truck ever made has a peculiarity when it comes to HVAC Blower Assemblies that is not noted in either manual or on any YouTube howto videos. I offer a few tips and thoughts that might help if ever you need to replace one.
1. When you actually pull the old blower out of the blower housing, it doesn't come out without some prying, mainly the fan blades against the housing. Being the old one you may not care if it breaks. but I suggest you remove it without breaking it, just in case something happens to the new one (more on that later). When you do pull it out, make sure the truck is very warm . It makes the fan more pliable and it'll come out easier than if it's cold (more on that later).
2. When you actually push the new blower in it doesn't go in without some prying, mainly on the fan blades, make sure the fan blades are warm. It'll go in much easier.
3. I recommend you note how far the new motor shaft is sticking out of the fan blade before you remove it. (more on that later).
I replaced the new fan blade with the old fan blade by holding/squeezing the fan blades between my legs and hitting the motor shaft with a 4 lb sledge. When the end of the shaft was even with the fan, I used a punch to drive it the rest of the way out. I did the same with the new blower/fan assembly.
Then I tapped the old fan onto the new motor shaft. After it was even with the motor shaft, I used a socket to tap it into position.
OK, here's what happened, It's evening around 90F degrees. I finally got the old blower/fan assembly out, it came out after a minor struggle on my part.
The next morning it was around 60F degrees. After a mighty struggle, the new blower assembly finally slipped into place, damned fan fought me all the way, but I thought after it slipped in I was the winner, not a chance. Patting myself on the back, I also made the mistake of putting everything else back together as well (dumb). Turned on the fan to hear a clicking noise at high speed. After uninstalling again, another mighty battle, I saw the fan had cracked in one spot. This is when I figured out the temperature had something to do with the mighty fight and the crack.
I took both the old and new to a mechanic who told me he didn't have the tools necessary to replace the new fan, which is cracked, with the old one, but he tried gluing it together.
After installing just the blower, this time I used my wife's hair blower to warm the fan blades and it slipped into place relatively easier than before by a long shot, and the ECM (Electronic Control module, I just set it in there and plugged it in) it ran for a couple minutes then started clicking on high again.
I pulled the blower out again (third times the charm? Uh-uh) then replaced the new fan with the old fan on the new motor (see note #3). Making sure the fan blades were nice and warm, I installed the blower, and the ECM again, it had a new noise like something rubbing. So I pulled it out again and adjusted the fan to the correct position on the motor shaft.
Making sure the fan blades were nice and warm, yeah I learned that lesson well, I Installed the blower, and the ECM again! This time, it ran like it should. Whew! All's well that ends well.
1. When you actually pull the old blower out of the blower housing, it doesn't come out without some prying, mainly the fan blades against the housing. Being the old one you may not care if it breaks. but I suggest you remove it without breaking it, just in case something happens to the new one (more on that later). When you do pull it out, make sure the truck is very warm . It makes the fan more pliable and it'll come out easier than if it's cold (more on that later).
2. When you actually push the new blower in it doesn't go in without some prying, mainly on the fan blades, make sure the fan blades are warm. It'll go in much easier.
3. I recommend you note how far the new motor shaft is sticking out of the fan blade before you remove it. (more on that later).
I replaced the new fan blade with the old fan blade by holding/squeezing the fan blades between my legs and hitting the motor shaft with a 4 lb sledge. When the end of the shaft was even with the fan, I used a punch to drive it the rest of the way out. I did the same with the new blower/fan assembly.
Then I tapped the old fan onto the new motor shaft. After it was even with the motor shaft, I used a socket to tap it into position.
OK, here's what happened, It's evening around 90F degrees. I finally got the old blower/fan assembly out, it came out after a minor struggle on my part.The next morning it was around 60F degrees. After a mighty struggle, the new blower assembly finally slipped into place, damned fan fought me all the way, but I thought after it slipped in I was the winner, not a chance. Patting myself on the back, I also made the mistake of putting everything else back together as well (dumb). Turned on the fan to hear a clicking noise at high speed. After uninstalling again, another mighty battle, I saw the fan had cracked in one spot. This is when I figured out the temperature had something to do with the mighty fight and the crack.
I took both the old and new to a mechanic who told me he didn't have the tools necessary to replace the new fan, which is cracked, with the old one, but he tried gluing it together.
After installing just the blower, this time I used my wife's hair blower to warm the fan blades and it slipped into place relatively easier than before by a long shot, and the ECM (Electronic Control module, I just set it in there and plugged it in) it ran for a couple minutes then started clicking on high again.
I pulled the blower out again (third times the charm? Uh-uh) then replaced the new fan with the old fan on the new motor (see note #3). Making sure the fan blades were nice and warm, I installed the blower, and the ECM again, it had a new noise like something rubbing. So I pulled it out again and adjusted the fan to the correct position on the motor shaft.
Making sure the fan blades were nice and warm, yeah I learned that lesson well, I Installed the blower, and the ECM again! This time, it ran like it should. Whew! All's well that ends well.
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