Welcome to 2CarPros.
Nick, the blower motor does have a high relay. It is under the hood on the firewall. See
pic 1.
Does the fan work on any of the speeds? If it still works on high only, the resister is most likely the issue.
As far as the blower motor itself, here are the directions. They are vague, but I should be able to help if you have questions.
______________________
1992 GMC Truck G 1500 1/2 Ton Van V8-350 5.7L
Procedures
Vehicle Heating and Air Conditioning Blower Motor Service and Repair Procedures
PROCEDURES
FRONT UNIT
1. Disconnect battery ground cable.
2. If equipped with 6.2L/V8-379 diesel engine, the blower motor and evaporator core is protected by an extra piece of insulation. To remove insulation, proceed as follows:
a. Remove parking lamp assembly.
B. Remove radiator overflow tank.
C. Remove retaining screws, then the insulation through hood opening.
3. Remove coolant overflow hose, coolant overflow tank, then power antenna assembly, if equipped.
4. Disconnect motor harness lead.
5. Remove five motor assembly mounting screws, then remove motor assembly. It may be necessary to pry on the blower flange, to remove the assembly, if the sealer acts as an adhesive.
6. Remove cage from motor after removing shaft retaining nut.
7. Reverse procedure to install, using new sealer if needed.
Pic 2 shows the blower motor location. If you can, run battery voltage to so you know if the motor is bad or not.
Let me know what you find.
Joe
Images (Click to make bigger)
SPONSORED LINKS
Thursday, October 10th, 2019 AT 7:25 PM