1993 chevy astro van

Blower motor is in dashboard. Problem could be with motor windings, bearings, fuse, relay, and switch. Check them all out.

Well, More information would be helpful like the year and model of your van. Most blower motors are accesed through the firewall from my experience. I owned a 1978 Chevy G-10 .Please provide more model specific information. Thankyou

2 fuses to check, Kevin: in the instrument panel fuse block, 20 amp fuse #12, Htr-A/C. In the under hood fuse block, Frt HVAC fuse, 30 amp.

The new resistor you put in, was it called a "Blower Motor Resistor and Relay Pack" ? It appears there is a relay there with the resistor, but appears to only be used with htr on high speed. However the low speed wiring is also routed through this relay. If it was the Pack you put in, guess that is not an issue.
In the Heater and A/C Control Module is the blower switch. The power in to the control module is a brown wire (from the #12 fuse in instr. panel). With key on should be hot. It appears the brown wire goes to the mode switch and then to the blower switch. Check for power in, and check continuity of both switches. Or check if blower switch has power to it, then check for continuity in it-it should have continuity in all speeds.
If all is good so far, you need to check if blower motor ground is good.
Here can be found a wiring diagram for your Astro. Look for heater controls under the system called "HVAC". Every wiring diagram and TSB for the Astro (or any make, model) can be found here:
http://www.bbbind.com/free_tsb.html
Good luck.

The blower resistor has gone bad which is why you lost blower speeds.This may have been caused by the blower motor drawing too much power. At this point I would verify that no fuses burned out and then check the pigtail plugs going to the resistor and blower motor to make sure the connectors and connections are not melted or wiring is frayed. These connectors are located in the engine compartment on the passenger side. After checking this and if everything appears ok then the blower motor itself has probably gone bad and needs replaced. I would also replace the blower motor resistor as well. If the connectors appear damaged replace or repair as needed .

try to tap on the blower motor with the switch in the on position the motor is located on the passenger side close to the firewall if it kicks on you need a new blower motor

check the blower resistor near the blower motor,

The relay is not your problem or it would blow wheather or not the heater motor was plugged in or not if it was shorted,you need a new heater motor.

It could be a bad blower motor - tap on the blower motor with the end of a hammer when you have the switch in the on position - if it comes on then it is a bad blower motor. If it doesn't come on I would check to make sure you are getting power and ground to the HVAC control head.

Yes, in high it bypasses the resistor and uses a high blower relay. But I think on 1998 Astro the High relay and the resistor are built together. It should be mounted in the blower box real close to the blower motor.

Blower/Heater Switch Operation: This electrical switch, located in a fuse or breaker protected circuit, controls the rpm of the blower motor through a series of control relays and a rheostat. Sometimes the A/C compressor clutch is energized by this switch.