Location of blower motor and relay(GM guy) - 1991 Chrysler New Yorker

normally it is the resistor,( relay) then resistor module then motor.
did you test the relay(I believe located under hood, relay/fuse center), If OK check plugs and wires for melting, damage and good connection, grounds should also be checked. Use a volt ohm meter to see if you are getting any power ti motor,etc.
the first link below gives good how to diagnose blower,press the helpful button
GM Blower Motor Resistor Diagnostics by Wells

DIagnose and Replace GM blower Control Module

http://www.gmcproblems.com/tsbs/Envoy/2003

check blower relay located under hood or passenger side kick panel also climate control panel is common problem on these and other GM cars

RELAY SHOULD BE ON TOP OF AIR PLENUM BEHIND GLOVE BOX (MOST GM)
THE RESISTOR IS LOCATED UP STEEM FROM BLOWER MOTOR (BOTTOM PASSENGER SIDE) CHECK FOR POWER AT BLOWER MOTRO CONECTION FIRST AND FUSE ALSO
VERY RARE TO LOOSE ALL SPEED AT ONCE UNLESS FUSE OR BLOWER MOTOR OR
SWITCH

Thanks for the opportunity to let me help. The blower control switch in your vehicle also uses a blower relay. This relay is generally located on the firewall on the passenger side near the heater fan. You can also look in you vehicle owners manual for the location of the blower relay, it may be also be located in the fuse and relay box under the hood. Generally speaking if the highest setting doesn't work on a GM vehicle it is a high blower Relay. This item is not expensive and can be purchased at most all you local Auto parts stores. If you have a Napa, Orielly's, or AutoZone these stores will also likely help you in the location if you are unable to locate this relay. Here is a general picture The installation of this relay is either to remove from the fuse box, or if located near the heater fan housing then you will need to remove the mounting screws, remove the wiring clip, then reverse to install. I hope that this has helped you. D.R. Wilkins

remove glove box, look on top of heater box in recessed portion. You will see a muti-wire plug facing up. This is the blower resistor. Check for burnt connections by removing plug (common problem). Blower high speed relay located above blower motor (also behind glove box). Check for burnt connections. Repair harness available through G.M. dealer.

The "Power Module " is bad, shorted. Its located on top of the blower motor housing at the firewall.

The rain had nothing to do with it. What ever GM told you was a quess,unless they worked on it. You never change parts until you know their bad. Have to at least know how to test relay, if you do find it. Stop by dealer,they will come out and remove it for free

fan motor will not shut off

There is a resistor attached to the blower box. Replace the blower resistor and this should solve your problem

INSTALLED NEW BLOWER MOTOR ON 2002 MERCURY G/M LS .WONT RUN ALL FUSSES & RELAYS GOOD