I can't get the radio out of the dash of my 1990 740 turbo sta wa

A Toyota Avalon radio is bolted in place in the dashboard in order to prevent theft. If you want to replace the radio with a more updated stereo or an in-dash DVD player, you'll need to unbolt the old radio. The bolts are concealed by the dashboard's trim panels, and there can be one or two other objects you'll need to temporarily remove as well.
Step 1 Shut off the power to the Avalon by disconnecting the negative battery cable.
Step 2 Pry off the central register panel above the radio on the dash. Use a trim stick or a flathead screwdriver with tape wrapped around the blade. With the register panel gone, pry off the dash trim panel that surrounds the radio. Disconnect the electrical connector to the clock.
Step 3 Remove the control panel for the air conditioner if it is blocking your way to the radio's mounting screws. Remove the front console trim over the air conditioning console, disconnect the mounting screws and remove the control panel.
Step 4 Disconnect the mounting screws to the radio using a small hex wrench. Put the screws aside in case you can use them to install the new stereo or other device. Pull the radio out of its space to find the electrical connector and antenna lead in the rear of the unit.
Unplug the electrical connector and antenna lead, and remove the radio. These connectors will be used with any new radio or stereo that you'll install in the old radio's place.

problem is usually the resistor, but switch may be going bad too. The resistor is next to the blower motor, above the passenger's feet. You may have to take the glove box out to get to it. See picture below. Also, please see my tip at http://www.fixya.com/cars/r6234839-doesn_t_heater_or_air_conditioner_blow for additional diagnostic info. Please get back to me if you have any questions.

REMOVAL & INSTALLATION, Climate Control Panel

1. Remove the center console trim fascia.
2. Remove the radio to allow access to reach behind the control panel.
3. Remove the control panel attaching screws.
4. Remove the center console bracket, if necessary, to allow for easier removal.
5. Separate the control panel from the trim panel.
6. Unplug the harness connectors and vacuum lines from the control panel.

To install:

1. Plug in the harness connectors and vacuum lines from the control panel.
2. Install the control panel into the trim panel.
3. Install the center console bracket, if removed.
4. Install the control panel attaching screws. Do not overtighten them, as they are screwed into plastic.
5. Install the radio.
6. Install the center console trim fascia.
7. Operate the climate controls and check for proper operation.

The trim is held in by sprung clips. Pry gently at the edge/corner with a small screwdriver until you can get your fingers behind it. Pull straight out. Here are instructions from autozone.com:

REMOVAL & INSTALLATION

Radio Control Assembly

1. Disconenct the negative battery cable.
2. Remvoe the shift lever knob.
3. Remove the console trim plate.
4. Remvoe the center air duct.
5. Remove the instrument panel accessory trim plate.
6. Unfasten the upper right corner console right hand trim pad-to-carrier screw.

1. Unfasten the bolts/screws securing the radio control assembly. Pull the radio partially for access to the electrical connectors, then unplug the connectors and remove the radio control assembly from the vehicle.

See Figure 1

Fig. Fig. 1: Exploded view of the radio control assembly

1. Installation is the reverse of the removal procedure.

Have your radio code before you pull it out with the right radio tool. This pull would involve removing this parts.

1. Glove compartment
2. Driver side panel
3. Center top dash board
4. Defrost switch carrier
5. Radio unit
6. Center lower half of dash

So I'd suggest go to your local public library and look for your car manual. It would be either Chiltons or Clymers manual, it's not as precise a Bentley VW Official factory repair manual. Yes it really involves taking all those parts out just to get to the rotary switch.

Radio & Tape Player

1. Disconnect the negative battery cable. If so equipped, disable the Supplemental Restraint System (SRS).
   
2. Remove the floor console and the front console panel. On 1984-85 cars, if access to the back of the radio may be gained through other means, such as removing the "pocket" from the console, the console need not be removed.
   

Radio mounting on 1986-89 Accords

1. Remove the ashtray and ashtray holder.
   

1. On 1986-89 cars:
2. Remove the coin box, air vents and ashtray lighting bracket.
   
3. Remove the dashboard switches on the left and right of the steering wheel.
   
4. Lower the steering wheel to its lowest position. Remove the dash visor. This is a large, one-piece assembly which includes the center dash trim. It's plastic; don't break it.
   
5. Remove the two screws holding the radio at the rear of the unit.
   
6. Carefully push the unit out the front of the dash. When access is gained, disconnect the multi-pin connector and the antenna cable from the unit. Remove the unit.
   
7. Reinstall in the reverse order. Take great care not to damage the dash trim and instrument visor. Make certain the connectors are firmly and squarely installed. If applicable, be sure to enable the SRS.
   

If you are talking about the pigtail for plugging in the brake controller, it is towards the left hand side of the center console trim panel ( the trim around the radio and HVAC ), just up under the dash.

This is almost in line with the gas pedal.

Remove the heater and A/C control and radio bracket fasteners.

Partially remove the radio and A/C control assembly.

Disconnect the electrical connectors from the radio and A/C control assembly.

Remove the radio and A/C control assembly.

Remove the radio retaining nuts.

Remove the radio from the radio bracket.

Installation Procedure Install the radio to the radio bracket.

Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.

Install the radio retaining nuts.

Tighten
Tighten the radio retaining nuts to 10 N·m (88 lb in).

Partially install the radio and A/C control assembly.
Connect the electrical connectors to the radio and A/C control assembly.
Install the radio and A/C control assembly.
Install the heater and A/C control and radio bracket fasteners.
Install the console trim plate. Refer to Console Trim Plate Replacement in Instrument Panel, Gauges and Console.
Install the instrument panel center trim plate. Refer to Instrument Panel Center Trim Panel Replacement in Instrument Panel, Gauges and Console.

The easiest way to remove the radio from a 1997 Acura TL is from the front. Assuming you know your anti-theft radio code, disconnect the negative side of your battery. See the last paragraph if you have lost your anti-theft radio code.
Next, remove the plastic wood trim from the dashboard surrounding the radio. To do this open the glove box, reach up inside and push out on one of clips holding the wood trim, as it comes loose grasp the trim from the front and carefully pull the trim until each clip unsnaps from the dash. The attached Heater/AC control panel above the radio comes off with the wood trim, so just unclip the 2 wire harnesses from the back and set trim panel aside.
Next, using a phillips screw driver, remove the 4 screws holding the black plastic radio frame into the dash, then pull the radio forward to remove it. Disconnect the 2 wire harnesses and antenna cable from the back of the radio to complete the removal. If you are putting in a replacement radio, just loosen the two small bolts holding the radio on the back of the frame, and then slide the radio out of the frame.

Set parking brake.
Place tranny in nuetral.
Disconnect Negative battery cable.
Open center storage compartment.
Gently pry handbrake trim panel up starting at cup holders.
Gently pry shifter trim panel up and rearward.
Pull receiver trim panel away from dash.
Disconnect electrical connections.
Avoid Large YELLOW cables, these are the airbag cables.

1. Disconnect the negative battery cable.

CAUTIONOn models with an airbag, wait at least 90 seconds from the time that the ignition switch is turned to the LOCK position and the battery is disconnected before performing any further work.

1. Remove the attaching screws from the trim panel.
2. Remove the trim panel, being careful of the concealed spring clips behind the panel.
3. Disconnect the wiring from the switches if so equipped mounted in the trim panel.
4. Remove the mounting screws from the radio.

Remove the upper and lower screws from both sides of the radio brackets

1. Remove the radio from the dash until the wiring connectors are exposed.

Extract the radio with brackets and ashtray out of the dash

1. Disconnect the electrical harness and the antenna cable from the body of the radio and remove the radio from the car.

Disconnect the wiring harness from the back of the radio, along with the antenna leadTo install:

1. Reconnect all the wiring and antenna cable first, then place the radio in position within the dash.
2. Install the attaching screws.
3. Reconnect the wiring harnesses to the switches if so equipped in the trim panel and make sure the switches if so equipped are secure in the panel.
4. Install the trim panel (make sure all the spring clips engage) and install the screws.
5. Connect the negative battery cable.
6. Check radio system for proper operation.

Good luck....