good afternoon. first post for me on this forum

my '01 suburban 1500 (120k miles) has an interior heat problem, in that the controls don't seem to control the blower fan speed nor temperature. the blower motor won't come on at switch positions 1, 2, or 3 - but works fine at position 4 & 5. the temperature control works fine unless it's turned all the way to the highest heat setting - then no matter where the temp switch **** is set, the heat remains at the hottest temp.

i've swapped out the control box (fan switch, temp setting ****, and outlet setting switch) with a known good one to no avail. has anyone run into this problem?

since the blower motor runs fine on the top two speeds - can i assume that the motor itself is fine?

there is a blower relay in the system that i'm trying to find - any idea where this relay is located, and the part number stamped on it????

i have aanother electrical gremlin to track down - that's the odometer display. the display is stuck on the trip odometer, and will not switch back to the regular odometer. any ideas on that one? seems like this is a guage cluster issue vice a sensor somewhere?

any idea where i can find detailed info on this truck .... haynes and chiltons just don't cut it. i can always take it to a dealer ... but i can only turn there as a last resort.

thanks

bill