Is the black w/ red stripe wire for the blower motor suppost to have battery voltage all the time? This is another thing I am checking into after we put the car back together. Whenever the wire is connected to the motor, it cuts on and makes a loud noise with key off or on.

 

No - not with the key off. If it's electronic air, the control panel sends a low voltage signal to the blower module mounted on the evaporator case. That signal should be a tan wire. At 1 - it should have 2.5 volts. At 10 - 6 volts. The Module amplifies the voltage and the output on the red/black should be 4 volts at 1; 12 volts at 10. Dash Controls monitors the actual voltage and the red/black wire is spliced back to the firewall, through a 5 amp fuse, and onto the controls. If that fuse opens, you can get battery voltage at all times and with the key off. If the fuse is good, usually it's because the module has an internal short. It's powered up at all times through the red wire which uses a fusible link to protect it. If you need to replace the module, it's used across the line, so any GM dealer should have it or NAPA has a stocking number. In light of the noise, you probably need a need a new blower motor too or the squirrel cage is falling apart.

If you have manual air, battery voltage is applied to a resistor pod mounted on the evaporator case. The resistors then vary the output so that blower speed matches whatever you have on the dial. Still shouldn't have any voltage with the key off. Check the red/black wire for a short to voltage in the engine compartment or it might be a funky blower relay.

 

Sun, Yes, but wanted to add that this is true except for High on the dial. On High the Blower Relay or High Blower Relay on later years energizes and routes battery voltage from the fusible link to the Blower Motor, bypassing the resistor pack. If this Relay sticks (the funky blower relay, as you metion), you'll get the constant Blower with ignition off on the Manual Air cars.

 

Thank you SunCr and Ray. I have the C68 electronic A/C control. It the actual unit does not work and just flashes a lot of numbers. I will need to replace this or check the connections behind it. The black with red stripe wire that connects to the blower motor always has battery voltage.....if the battery is connected, that wire is hot. I have a spare blower motor and squirrel cage. I will need to study and search a little more in the FSM. Thanks again.

 

Anyone know if the blower module off a 91 will fit an 86? Like to know before I make a 2 hr drive to pull it from my wrecked 91.

 

No - '91 uses the ECM to ground the compressor relay. Your '86 includes that ground circuit (along with Blower Control) and there isn't a relay. You can look up you part at www.acdelco.com and then cross-reference for all the Years and GM models it works on. (Hopefully it's still a stocking number).

 

http://members.shaw.ca/dankai/AC%20Electronic.pdf

 

SunCr, thank you for taking your time to answer my question. After more searches, looks like it will fit 86-89. I'm looking for the module as it seems it needs replacing. Also, thank you Dan for the link.