Hi all-new here. Looked at some of your older posts-saw the same problem I have. 98 Grand prix--no blower speed on 1.2.3.4--high speed ok. Replaced resisitor--hooked up new one but did not install all the way--did not fix problem--different motor did not fix problem. When you turn the ign. on headlight will come on--I am presumeing auto headlight system because taillights come on. When you go to speed 1-no problem, speeds2,3,4 will turn off the headlights and turn off the A/C compressor--go to high speed and light come back on, blower works and so does the A/C. Any help would be greatl;y appreciated. Thanks