heater/ac blower rumbling noise ?
 

I have a '97' , when I turn on the heater fan, I get a screeching sound that comes and go's... it's fine when the screeching sound go's away...but what's up with that ?

The bearings in the fan motor are most likely going bad. The motor is easy to replace and not too expensive. Some people have had luck just using some oil on the bearings but eventually it will need to be replaced.

Agree with BigGun. Had the same noise issue. I was able to save myself some on the motor by oiling and packing the bearing with synthetic bearing grease through the small top hole on the motor bearing casing. I did the repair about 2-3 months ago and it's been quiet since.

thanks,... I guess a new blower motor is in order given the age and history...

Regardless, the job is pretty easy but beware, it's back-breaking

Consider removing the seat to improve access. It is only 4 nuts and an electrical connection (if powered). Well worth the time and effort to avoid frustration due to access.

Blower motor is only 3 bolts and a connector. If you're not a really big person it is not that bad.