QuestionI have a 99 sonama 4.3 motor.Warmed the truck up the other night for my wife and the blower worked fine.Shut it off she got in it 1 hour later and had no blower .I sent her off in my car and went out later to the truck and only had position 3 out of the 4 positions on the blower control.I was told I needed a blower resister.So i picked on up installed it in my truck and now I have positions 1,2,3 and no 4 high.This has got me really confused!!!We had another truck out where I work so I put my old blower resister in it to see what it did and it only gave me 4 high speed and no 1,2,or 3 position in that truck where in my truck it gave me position 3 only .I was told the system also had a blower relay which I am not sure where it is located .I did see a relay on the fire wall not too far from where the blower resister was located under the hood of my truck so I replaced it and it made no difference still 1,2,3 no 4.Any ideas on what is going on ? And was that relay I did replace a blower relay or is the blower relay located somewhere else in the truck? This has got me confused for sure .Any help would be great on what I might need to do .Thanks you very much !!!!
AnswerRick , Here you Go !!!!!!
The resistor blocks control the high speeds on the blower motor.
The reason you put it on the other truck and it worked 4 speed only . It's because the wiring going to it might be different from the switch ?
The relay is located next to the blower motor : under the hood .
You can test the switch with ohm meter . Make sure that each position is reading on scale , make sure you have continunity...
If the switch is good then you go to the relay , then to the resistor block .,,, Take your switch on the dash and spin it threw the speeds FAST .>>>>> back and forth >>>>>>>>FAST . see if this loosens up the speeds for you.
The parts that control are as follows:
Fuse Box >>>to switch>>>to relay >>>to resistor block >>>>to blower motor >>>>
Let me know !!!!
Dave G
