Fuse 7 and 14 tested ok.fuse 111 and 114 are maxi fuses and I don't see test points on them, but they don't look burned out. I also saw an earlier thread showing how to check the resistor. I have continuity on the rear resistor. Around 3.5 ohms on each test. I also tried the jump test for the blower and got nothing. The jump test post I saw was for front blower though, I believe, so I'm not sure if it would be different for the rear
No rear heat or ac
- Thread starter rjr71
- Start date
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Bedrck47
Full Access Members
Measure the resistance between the auxiliary blower motor resistor terminals shown on the chart.
Terminal To Terminal Resistance
3 to 4 0.5-0.7 ohm
3 to 1 2.5-4.0 ohms
3 to 2 5.5-8.5 ohms
Look at the connector for the blower motor resistor
Pin 3 will have the OG/RD wire
Pin 4 will have the DB/WH wire
Pin 1 will have the LB/OG wire
Pin 2 will have the RD/PK wire
disconnect the connector and read the above terminal to terminal values
Also check fuse #23 in the central junction box
wpatters1229
Well-Known Member
I have a 2000 and the controlling of the vents etc is all done with vacuum. There is a line that goes through the firewall and behind the dash. Be the guy who put in the radio knocked it loose. i had the line break on the side of the engine and nothing worked but air through the vents for the defrosters. Fixed the vacuum line and all worked.
Bedrck47
Full Access Members
This may be good advice for the front vents etc But there is no vacuum controls/vents for the rear heat or A/C
I pulled out the dash area by the radio and I don't see anything that seems to be unplugged. I'm not sure what the readings at the rear resistor should be but I'm assuming that if there is continuity I would be getting something. Is there a way to test if I'm getting power to the resistor plug for sure. Can I test for power at the plug? And if there is power at the plug would it just be the blower motor is dead?
I did notice when I pulled the main climate control unit out that it looks like it has 6 connections for vacuum hoses but only 5 are plugged in but when I look I don't see any that look to be unplugged and the 5 that are plugged in are all tied together like they are the only ones that should be.
Bedrck47
Full Access Members
Symptom Chart
Condition Possible Sources Action
Condition Possible Sources Action
- No communication with the electronic automatic temperature control module
- Circuitry short/open.
- EATC module communication network.
- The EATC system is inoperative, intermittent or incorrect operation
- Circuitry short/open.
- Input sensor(s)/erratic input signals.
- Charging system.
- Automatic temperature control sensor hose and elbow.
- Incorrect/Erratic direction of airflow from outlet—Manual Climate Control
- Function selector switch.
- A/C vacuum check valve.
- Vacuum hose.
- A/C vacuum reservoir tank and bracket.
- Vacuum control motor.
- Vacuum actuator arm.
- Incorrect/Erratic direction of airflow from outlet—EATC
- No vacuum to the A/C control.
- A/C control leaks vacuum.
- Vacuum hose kinked or pinched.
- Airflow door binding or stuck.
- Vacuum control motor.
- A/C vacuum check valve.
- A/C vacuum reservoir tank and bracket.
- Vacuum actuator arm not connected to the door crank.
- The air conditioning (A/C) is inoperative/does not operate correctly
- Open fuse.
- Circuitry short/open.
- A/C cycling switch.
- A/C system discharged/low charge.
- A/C pressure cutoff switch.
- A/C control.
- The air conditioning (A/C) is always on
- Circuitry short/open.
- A/C cycling switch.
- A/C control.
- No operation in all temperature settings—Manual Climate Control
- Temperature blend door.
- Temperature blend door actuator control.
- A/C electronic blend door actuator motor.
- Circuitry short/open.
- The blower motor is inoperative—Manual Climate Control
- Fuse(s).
- Circuitry short/open.
- A/C blower motor switch.
- A/C blower motor resistor.
- A/C blower motor.
- The blower motor is inoperative—EATC
- Circuitry short/open.
- A/C blower motor.
- A/C blower motor speed control.
- Blower motor relay.
- No operation in high blower setting—Manual Climate Control
- A/C blower motor resistor.
- A/C blower motor switch.
- No operation in lower speeds — Manual Climate Control
- Circuitry short/open.
- A/C blower motor resistor.
- A/C blower motor switch.
- The blower motor operates continuously in high speed — Manual Climate Control
- Circuitry short.
- A/C blower motor resistor.
- A/C blower motor switch.
- Blower motor relay.
- The blower motor operates continuously in high speed—EATC
- Circuitry short/open.
- A/C blower motor speed control.
- EATC module.
- No operation in some blower speeds—EATC
- A/C blower motor speed control.
- A/C blower motor.
- EATC module.
- One or more steering wheel control switch is inoperative
- Circuitry short/open.
- Steering wheel control switch.
- EATC module.
- Redundant steering control module.
- The temperature set point does not repeat after turning the ignition switch OFF — EATC
- Fuse(s).
- Circuitry short/open.
- EATC module.
- CHECK circuit 729 (RD/WH) for a short or open and repair as necessary. If okay, INSTALL a new EATC module.
- The temperature display will not switch between Celsius and Fahrenheit — EATC
- EATC module.
- PRESS the MAX A/C and DEFROST buttons simultaneously for at least 0.75 second. If the temperature display does not switch between Celsius and Fahrenheit, INSTALL a new EATC module.
- The auxiliary blower motor does not operate—EATC
- Fuse(s).
- Circuitry short/open.
- EATC.
- Auxiliary blower motor relay.
- Front/rear auxiliary blower motor switch.
- Auxiliary blower motor.
- Auxiliary blower motor resistor.
- The console blower motor does not operate—EATC
- Fuse(s).
- Circuitry short/open.
- Console blower motor.
- Console blower resistor.
- Rear integrated control panel.
- The auxiliary blower motor does not operate—Manual Climate Control
- Fuse(s).
- Circuitry short/open.
- Function selector switch.
- Auxiliary blower motor relay.
- Front/rear auxiliary blower motor switch.
- Auxiliary blower motor.
- Auxiliary blower motor resistor.
- The console blower motor does not operate—Manual Climate Control
- Fuse(s).
- Circuitry short/open.
- Console blower motor.
- Console blower resistor.
- Rear integrated control panel.
- Insufficient, erratic, or no heat
- Low engine coolant level.
- Engine overheating.
- Plugged or partially plugged heater core.
- Temperature blend door binding/stuck.
- A/C electric blend door actuator.
- The auxiliary blower motor does not operate correctly
- Circuitry short/open.
- Function selector switch.
- Front/rear auxiliary blower motor switch.
- Auxiliary blower motor resistor.
- Auxiliary blower motor relay.
- The auxiliary blower motor does not operate using the rear auxiliary blower motor switch
- Circuitry short/open.
- Rear auxiliary blower motor switch.
- The panel/floor control does not operate using the front/rear auxiliary climate controls
- Circuitry short/open.
- Front/rear auxiliary potentiometer.
- Auxiliary blend door actuator.
- Auxiliary climate control module.
- The temperature control does not operate using the front/rear auxiliary climate controls
- Circuitry short/open.
- Front/rear auxiliary mode potentiometer.
- Auxiliary mode actuator.
- Auxiliary climate control module.
- The panel/floor and cool/warm controls do not operate using the front/rear auxiliary controls
- Circuitry short/open.
- Auxiliary climate control module.
- The panel/floor switch does not operate, the console blower does operate
- Fuse(s).
- Circuitry short/open.
- Console door actuator.
- Rear integrated control panel.
- The auxiliary controls are operational with the function selector OFF
- Auxiliary blower motor relay.
- INSTALL a new auxiliary blower motor relay.
- The rear auxiliary blower motor switch operates only in HI
- Auxiliary blower motor resistor thermal limiter.
- INSTALL a new auxiliary blower motor resistor
I did some more troubleshooting last night. I have power all the way to the rear blower relay behind the panel but not getting anything at resistor or blower plugs. There are no other connections in between and not seeing any shorts on wiring and I tried changing the relay as well
