Surging Blower Motor

[LDeane]

Have had my 2004. 5 for about a week now, when I have my heat or AC on at lower settings, the blower will sometimes blow hard for a bit, and then blow softer. Seems to stop after a while, and only noticed it on lower settings, not the higher settings. Anybody else have this problem?



Was wondering if it was something in the truck just using lots of juice for some reason...



Any help would be appreciated, and not a big deal just a little annoying.



-LDeane

 

[Bertram65]

If it occurs when you first start the truck up could be the grid heater cycleing on and off that is causing the difference in blower speed. It goes away after the truck warms up or goes over a certain speed, I thought I had read like 18 MPH.

 

[LDeane]

Well, maybe that's it. I noticed tonight that when I turn on the interior lights right after starting the engine, they "brown out" as well too, going from bright to dim and back. Engine was warm though...



I do notice on the blower that it seems to stop after I get moving.



-LDeane

 

[lil red cummins]

i have experienced both of those things. the alternator does not charge until the grid heaters are done cycling which is either by time or until you hit 20 MPH. watch your volt gauge to verify this.



jim

 

[RonWeiss]

Grid heatersOo.



Ron W.