Blower motor exploded, replaced, now fan speed 4 and switching modes doesn't work
 

Hey guys, I'm new here so I hope this is the right area. I inherited a 98 blazer and it's got its quirks. I don't drive it too much as it's my second vehicle, but a few weeks ago I had taken it to work and was sitting it putting music on my phone before I leave and while I'm on my phone I hear a clunk and a bunch of noise and my blower shredded itself (I found that out later). If I put it on fan speeds 1-3 it would try to spin and on fan speed 4 it did nothing, but it I seem to remember that it buzzed. I replaced the blower motor and it blows, but now fan speed 4 does not work at all, but 1-3 do. In addition, the fan modes do not switch. I now only have head and feet and now defrost which is a concern come winter time. My question would be was are the chances that the switches are bad in the climate control unit. Is there a way to inspect this? I'm not sure if the two are related or if it's just a coincidence. I know fan speed 4 bypasses the relay so I'm not sure if I broke something there while replacing the blower motor, or if something blew the relay and caused issues given the fan speed 4 issues? With not being able to switch fan modes I wonder if the climate control unit is bad and it's not working because of that. Although I have read that it could be a vacuum leak or a something stuck in the vents that switch directions but I thought I got all of the fan pieces out.

I'm just not really sure where to start and what the logical approach would be. I've daily driven and worked on Hondas for 5 years so this is a bit of a change for me. Any help or guidance is greatly appreciated!!

Check HVAC fuse 30 amp under the hood, you might have blown that when the blower motor had an unscheduled rapid deceleration. It’s the power for speed 4. If that’s not it switch the relay with a known good one. If that’s not it then we break out the meter

Georg

So I did replace the fuse and now it works on fan speed 4! Any way on how to trouble shoot fan modes not switching? Thanks!

PM christine_208, she's good with HVAC mode issues.

George