I just rebuilt the blower on a 4.8 and got everything back together and fired it up and the RPM of the blower pins out when I turn it on! I believe it was arround 15 before I took it out but can't remember! Is the magnetic pickup on the second shaft of the blower the sender of the signal for the RPM on the panel? If the sender has a bad ground will it cause the guage to pin out to max? I don't think the blower is turning to fast I just think I just have a bad conection in the wireing! It goes to max before the blower reaches full speed! thanks Adam
The RPM guage on the on the panel of the 4.8 below the waste tank inlets! 03 express van no RPM guage. It seems like the guage races to max to quick to acually be the RPM of the blower or the engine! it sems like everything is fine other than the RPM guage seems to not be working correctley! but also the pods could be out of adjustment and the engine is not set to 1400-1600 RPM's I wish I had more experience with the 4.8 but I purchased the van and pulled the blower out because it had a bearing that was out and didn't want to do more damage! I only heard it run for about 10 MIN.
You can always go to the auto parts store and rent an rpm meter with inductive pickup and hook it up to the number one plug wire on the van engine and get your reading that way. Thats a temporary fix to keep your mind at ease.
The RPM guage should be reading between 14 & 16. It reads about 34 maxed out! I don't think everything is turning that fast! On the Blower there is a pulley with a magnet and a pickup, what is this for?
It has to be a hall effect sensor but I am not familiar with hydra master. I'd put my money on it. Disconnect the sensor wireing and check the resistance. It should be steady on the multimeter. If your resistance jumps around the sensor is bad. Also, try cleaning the magnet and sensor and see if that helps.
Turns out one of the wires I put a new conector on had a bad conection! black corrosion/film on the wires, cleaned it up and works perfect!
