97 Impreza with blower issues

[Ogden]

Hey all,

 

So I did some searches ont he forum and read up on other folks who have had blower problems with Imprezas. Mine does not seem to be the result of varmint infestation or the relay pack (though I would not rule that out comepletely.)

 

So here's the scoop: 97 Impreza OBS with 250+K on it. (I drive a lot)

 

The blower works intermittantly, and if it is working, it only seems to work with the AC on. So, if I just get in the car and go, the blower will not work on any setting (1-4).

 

However, as I do a lot of highway drinving, I can still have some success witht he AC by leaving the vents open to outside air, and the ac on. In order to start the AC you have to have the blower switch on 1-4. So every now and then, as I'm driving with the AC on, the vents open, and the blower switch on (usually 1) to enable the AC, the blower just starts. When it starts, it will run independently of the AC (I can switch the AC off and it keeps going) and it will run until I shut the car off. Next time I start the car, it's not working again.

 

I can attribute the motor comming on to particular condition, temp, humidity, warm engine, cold engine etc, except that the blower motor has never, that I can recall, started while driving around town. It only seems to come on when I am out on the highway.

 

I can hear the blower relay click (not that that means anything except it is getting power)

 

The blower switch works to enable the AC, so at least it is getting some kind of power, and making some kind of electrical contact.

 

The blower motor does come on occasionally, and sounds OK. A little bit worn, but it has 250K under it's belt. I would not rule this out as the problem.

 

Last, this has been a problem before, about 2 years ago, but after a few weeks of being problematic, and just about the time I decided I had to do something about the problem...it vanished an resumed working normally. I do not appear to be so lucky this time as it seems here to stay, and while I can live with the heat of summer, in another 8 weeks I'm sure I'll be looking for the heater to work...or at least a certain regular passenger of mine will.

 

My current methodology is to start with the easy stuff and work to the harder stuff and hopefully fix it somewhere along the way but I was wondering if anyone has any better insight than I into what might be causing the problem.

 

Barring that, I keep hearing that the location of the blower motor is an issue and that perhaps it's replacement is "best left to professionals". I have no problem taking the dash apart, but my experience with that is mostly things like light-bulb fixes, stereo installs, and smaller problems, and the only time i have been into the dash on this particular car was to fix the stereo, so I guess I will be in new territory and I don't want to go in blind.

 

Any help/tips would be much appreciated.

[Cougar]

I would start checking for power to the fan while the problem is happening. Use a test light or voltmeter to check for power.

[Setright]

Remove the glovebox and the panel covering the heater matrix - if there is such a panel in your model.

 

Have a look round for loose connectors, fouled connectors...the usual stuff. Might be enough to solve the problem.

 

If not, get a wiring diagram - or work it out - and hook a bulb to the power connection of the motor and you can check if it's getting power, even when it doesn't run. If so, the motor is busted.