AC Blower not working even after replacing resistor

[Jskingry]

Hello all,
1st edit, this is a 1993 K1500 Silverado with a 5.7l V8 and 3 speed air conditioning blower.

So I finally got my Air Conditioning working, I replaced hoses, condenser, and pretty much every moving part under the hood except the compressor. It would only blow on high but living in Florida that was good enough until I got around to replacing the resistor which I have read causes the other speed to not work.
Yesterday I went out and started the truck to take it to a friends house to work on another project and the AC was not working at any fan speed. On the drive I hit a solid bump and it worked on high again. Once I was ready to return home it did not work again, today I took the glove box out and went to Napa to buy a new resistor. I installed the resistor and still nothing from the fan, you can hear a slight click from the resistor area when you change fan speeds but nothing from the blower.
I do not have my multimeter with me so I tested it with a 12v tester, all fuses are good. The motor is getting voltage as I pulled the purple wire and tested it. So I feel like this could be 2 problems:
1. I still have a weak ground from the motor to the firewall, that is on my list to be replaced next.
2. The blower motor? Maybe it has died?

So my next steps will be to replace that ground and test, then replace blower motor and test.

Am I on the right track here? Thoughts?

 

[GoToGuy]

Recheck the ground wire, where it attached to the motor and where it attaches to body to complete ground circuit. And or use some test leads with small alligator clips attach to motor ground point , attach other end to know good ground , nut bolt dash support rod. To test, if that fixes it, repair the OE ground wire. Don't assume in electric work. You'll just end up with spares on the shelf, ( money and time wasted). If you have knowledge basic DC voltage, get the OE service manual, the step by step testing is easy to follow and complete with test light and or multimeter. Use the search bar above search " service manuals " you'll find the post with links for free PDF look for your year. Nothing is better than the OE, unless ya got an extra $3000 for complete online everything access.

 

[Schurkey]

Perhaps a moderator will move this out of "Engines" and into OEM + Custom Interiors.

My '97 had blower issues. Didn't run at all (popped fuses including a 60-amp Maxi Fuse) because the blower motor drew excess amperage. Replaced the fuses and the blower motor, and then it ran on high only (failed thermal protection device on the blower resistor.)

My '98 Monte Carlo also had a failed thermal protection device on the blower resistor. The resistor coils are fine, but the thermal device is popped. (and the whole thing is rusty from being under-water due to a plugged A/C drain nipple.)

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If a guy could buy a twenty-cent thermal protection device and splice it in, the blower resistor would work again...most of the time. A jumper wire across the thermal device got the lower blower speeds to work again. So the cheap 'n' dangerous method would be to just solder-in a permanent jumper wire.

 

[GoToGuy]

Reminds of a friend's idea of , not having a replacement glass buss fuse, so he took out his Wrigleys chewing gum wrapper, the foil backed type, wrapped the fuse and stuck back in.

 

[Erik the Awful]

On the drive I hit a solid bump and it worked on high again.

You have a loose wire, loose connector, or loose ground. It is possible that the wiring inside the blower motor is loose, but you need to check your wiring harness first.

 

[Jskingry]

You have a loose wire, loose connector, or loose ground. It is possible that the wiring inside the blower motor is loose, but you need to check your wiring harness first.

Well I tested with a ground straight from the battery and nothing so I replaced the blower motor and it's working again blowing harder than before and has all 3 speeds.

Thanks