Not On The Same Page!

[leehljp]

How hard is it to get to the fan motor? On many cars it's either poking through the firewall into the back of the engine bay or hangs down into the passenger's footwell. If you can see the electrical connector, try unplugging it... then install a fuse. If the fuse blows/kaputs/fries/burns-up/dies/etc. when you try the switch on HIGH then it's not the motor; it's wiring or the switch or something laying on the backside of the switch (I've found paper clips in all sorts of oddball places behind dashboards!). I'll bet the fuse does die; it'd be odd for the fan motor to kill fuses on HIGH and yet actually operate/run normally at other speeds via the resistor.

Another common problem with blower motors, especially those that hang from the bottom of the big plastic housing: water accumulation. There is supposed to be a drain hose on the bottom of the plastic housing around the air conditioner evaporator (part that chills the air) to drain off the condensation that naturally forms. Even cars without A/C typically have a drain hose simply because water vapors naturally get into the system and can condense. If this hose is blocked, water pools in the housing and eventually can get into the motor. Small leaves are the typical reason for a blocked hose. A stiff wire (coat hanger) stuffed up the drain hose is often all that's needed to fix it. The hose will either poke into the engine bay through the firewall (angled downwards) or will run along the passenger footwell floor and through the bottom of the floor. Sometimes you have to unclip it from the plastic housing inside the car... have a bucket and rags/towels ready for the flood waters! And remove the carpets first if possible.

mpc

THANKS for this information. I didn't see it when you posted it but the first part makes sense (second part does too, but the first part sounds like what we need to check. Thanks for the suggestions!

[LCHIEN]

Ah fuses. In Electrical Engineering Lab 201 and 202, all the instruments wer issued to us by serial number and everything was fuse protected, even the component boxes we used in the experiments. You were supposed to check your wiring diagrams and the wiring and if you hooked it up wrong and blew a fuse you had to go ask the professor for another fuse and explain why you managed to blow it (almost always stupidity). That was a humbling experience. Heaven forbid you ask for two in a row. I think we (my partner and me) only managed to blow one the whole year. I don't recall how we decided which one of us would go ask for it. Ah the good old days.

I still check my setups to this day. Did you know the 10A fuse in a Fluke 85 is a special $12 or $20 item that you can't find just anywhere??? Honest, prof... I didn't blow it, just wanted to have a spare....

[All Thumbs]

I suspect she needs a new blower RESISTER.

[jseklund]

+1 on the resistor - sounds like the classic case.

Probably a $30 part....

[leehljp]

+1 on the resistor - sounds like the classic case.

Probably a $30 part....

You fellows are great! I will google the part and changing procedure so that I will know what to do when I get there - probably late April or early May.