I heater blower motor only works in speeds 2 and 3. I do not get anything from low and high. This is on my 91z28. Car org had A/C but I ditched it but kept the stock 4 speed blower motor and controls. Nothing changed in the wiring. I cant confirm that it started after I ditched the A/C because my car has been a huge work in progress. Could it be my resisitor or the relay?

 

possibly the resistor

 

gee I wonder if GM even sells these or maybe autozone. Thanks for the help

 

try junk yard i had simmilar problem in my blazer i picked one up really cheep there fixed it

 

if you only have 2 speeds its deff a blower motor resistor, i've seen it hundreds of times on many different vehicles and its fixes it everytime...and i wouldn't worry about going to a junk yard for one...there pretty inexpensive