blower motor or blower resistor?

[rgnjc]

Hi,

I have a 2005 Vibe AWD and a few days ago my cabin fan stopped working, but would intermittently come back on. When it does work it will only work on the highest 2 settings, and doesn't work on the lowest 2 settings. Today it wasn't working, so I performed percussive maintenance on the underside of my dashboard on the passenger side (I smacked it hard) and it came on immediately (but still with poor performance).

Is there a test or way to tell if it is the motor vs. the resistor? Both are about $30-40 so I'd rather not replace both if I don't have to. To replace them I plan to follow directions as outlined here: viewtopic.php?f=28&t=29211&hilit=replac ... r+resistor" onclick="window.open(this.href);return false;

Thanks!

[vibrologist]

I found this on a Ford Truck forum about testing a blower resistor:

You need an ohmmeter with a good low-resistance range to measure the actual values. Those resistors have values around a few tenths of an ohm. If you are reading continuity at each end of each "coil" they are almost certainly OK. Of course if there is a burned area and the ends are just barely touching all bets are off, but you could see that easily.

The other two-lead widget is a thermal fuse which opens if the resistors get overheated (for example, if a mouse nest in the heater box catches fire. Don't ask how I know). If it's open I believe you will not get any fan including high.

My Ford dealer has them for my '84 F150, for $23. Pep Boys, etc. did not.

It should be very similar in a Pontiac Vibe.

[joatmon]

unfortunately, not working on the lower speeds and working on the higher speeds is the classic symptom of a a bad resistor, and working
intermittently is a strong indicator of worn brushes in the blower motor.

On mine, the lowest fan speeds are really quiet, so make sure they really don't work, and then I'd probably go for the resistor first, but you may end up also replacing the blower motor. But its hard to say for sure from this side of the internet

[sideshowalan]

Bad resistor usually means it will only work on the highest setting.
The blower working on multiple speeds and needing an engineers tap leads me to think the blower is bad.

[rgnjc]

OK Thanks! I'll just replace both then.