What’s a “blower motor resistor?”

Back in Iowa, we had a little issue with mice deciding to keep warm inside our cars.  In the Sportage, they ended up chewing on the spark plug wires.  In the Scion xA, a dead mouse was found in Brooke’s cabin filter (after it had been chewed through, in building a nest).

Around that time, though, her car’s fan stopped working at all the lower settings: it only worked on “high.”  Since the fan still technically worked, and we didn’t want to pay some ridiculous amount of money to figure out what the problem was, we opted to let it go for awhile.  We didn’t really need the car in the summer, so much, and if it was crazy hot (or crazy cold, as Iowa tended to be), then it could still be heated and cooled: just somewhat loudly.

Well, awhile back, Mallory started having a similar issue with her Jeep Grand Cherokee, so she and Mark started investigating and tracked it down to the blower motor resistor, which tend to be faulty in Jeeps.  She ordered one and had Mark install it.  As I happened to be in town, I helped (read: watched…) Mark put it in.  In total, it was a relatively simple process, with the removal of the glove compartment being the most difficult part.  Thus, I figured “heck, I could do that with Brooke’s car!”  A new resistor is around $30, so it would save a ton of cash to do it this way, and I’d pretend to know something about auto repair in the process.

When this kind of thing happens to a car, it can either be due to the blower motor itself, or the resistor.  Because the fan still worked on high, it was unlikely the fan motor was the problem.  Conceptually, the idea of the resistor failing (the electronic unit responsible for applying a “resistance” to the speed of the fan, thus allowing for slower fan speeds) seemed to be likely.

Well, Brooke’s car, being a small, Scion xA, turned out to be a bit more complicated.

After I removed the glove compartment, it took me awhile to even find the resistor.  It wasn’t in the same place as a Jeep, and things tend to be a bit more cramped in a small, Japanese car like ours.  The internet wasn’t much help in locating it, either, though I found a few hints (and no pictures…so hopefully this will help some poor schmuck someday).

I spent a great deal of time trying to figure out how to remove the white panel pictured above, which houses the fan motor itself, as it seemed like the resistor was somehow a part of that assembly.  I didn’t have much luck removing it, though.  Beneath that panel was an engine relay assembly, and that was a bit easier to remove.

I was careful to write a few numbers on these wires, so I wouldn’t accidentally put them back in the wrong ports.  Then, removed the assembly and…

….there it was…way the hell back up behind that white, plastic, fan motor assembly.  And, believe you me, I had to contort myself in any number of ways to get into a position where I could even remove the thing.  Only took two screws, but getting a screwdriver to fit back there was challenging.  After a little maneuvering, I removed the resistor.

So yeah.  Not supposed to look like that.  Obviously.  In general, electronic devices don’t like birds, mice, or nests being made upon them.

In the end, I was able to get the car re-assembled and the new resistor works.  $30 fix from the O’Reilly Auto Parts up the street.  Took me about 2 hours, though most of that time was spent trying to find the stupid thing in the far reaches of the void behind the glove compartment.

Regardless, I was pretty proud of myself.  🙂

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