07 9400i front blower only works on high

[IUFAN87]

My friend has an 07 9400i and the front blower only works on high. Any ideas on most likely problem?

[bender]

Blower resistor.

[IUFAN87]

Blower resistor.

Thanks for the reply. Any idea where it is located?

[Heavyd]

Pop the passenger seat off, remove your plastic cover with cup holders, remove the sheet metal lid to the blower box and it will be right there near the front, upside down.

[stranger]

If that's not it, check the electrical plug on back of the blower switch. IH had several years where these would melt from heat.

[Shaggy76]

Use a dmm and test voltage coming into plug on different settings to verify not a head unit problem.

If plug is melted, change resistor with it. In my International Diamond Electrical certification training, the thought is the heat of the bad resistor is what made plugs melt.

I give it a 90% chance that resistor is bad. That year of truck will have a acm code on chassis info display for resistor.

[Heavyd]

Actually a real quick test of the control panel is to select different speeds between low and med-high and you should hear the med-high relay clicking in the fuse panel.

[silver dollar]

Pop the passenger seat off, remove your plastic cover with cup holders, remove the sheet metal lid to the blower box and it will be right there near the front, upside down.

My '02 has the same problem. But I don't seem to understand the location you gave. Is the resistor under the passenger seat?

[Heavyd]

Yes, the blower box housing is under the passenger seat. The seat comes off, (sometimes you can just undo the seat belts and the four bolts that hold the seat down and just tip it over into the bunk out of the way if you have a sleeper unit, those seats can be kinda heavy). Under the seat, most trucks have a plastic trim panel with some molded in cup holders and pockets, that plastic panel will just lift off once the seat is out of the way. Now you have the blower box exposed. Take out the bolts around the top (take note to the empty bolt holes, those are where your seat bolts will go back in.) Then just take the top off. Now you should see all the goodies in there. The resistor is about 1 inch wide by about 2 inches long. It has a bunch of resistor coils on in, but that side goes down, so all you see is where the wires go in at the top side. Should have 3 or 4 heavy gauge green wires going to it. I think you can just lift it straight up.

[IUFAN87]

Thanks for all the replies guys. He replaced the resistor, and that did the trick.