960 heater not working

[Finnvolvo]

I have a 97 960, and it has the blinking light from the ac. All the controls work fine, but no heat.

The lines to and from the heater core are hot. But no heat... can anyone help?

I don’t really want to run the codes at the dealership for $100 before trying to fix it myself.

[Finnvolvo]

Need to fix this! My wife’s car, and she’s freezing!!!

[RickHaleParker]

The blinking light means the EEC has detected a fault.

SELF-DIAGNOSTIC SYSTEM

The EEC system incorporates a self-diagnostic function that indicates system faults through a series of trouble codes. The presence of fault(s) is indicated by flashing A/C OFF button. The control panel is programmed to enter a pre-programmed mode when a fault is detected. Under fault condition, control panel ignores the faulty signal, selects an alternative pre-programmed value and prevents delivery of faulty output signals.


To enter Self-Diagnostics mode:

• 1. Ensure engine is running.
  2. Shine a non-fluorescent, bright light on solar sensor (LED on the dash).
  3. Place blower fan control knob in AUT position
  4. Function selector knob in vent position.
  5. Place temperature control knob to maximum cooling (pointing straight down).
  6. Ensure recirculated air switch is depressed.
  7. A/C OFF button is released.

Self-Diagnostics mode is enabled.

8. Request a code:

• Depress and release A/C OFF button within 5 seconds to start self-diagnostic mode.

Each fault code consists of 3 digits. For example, Code 132 is displayed by a single flash of the A/C OFF button for the first digit (number 1). After a pause, the second digit of code (number 3) is indicated by 3 flashes. After another pause, the third digit of code (number 2) is indicated by 2 flashes. See TROUBLE CODE IDENTIFICATION table.

Three different fault codes may be stored in memory. However, only one code may be displayed upon request. It may be necessary to request display of fault codes a number of times to ensure all fault codes are displayed (Step 8 above).

Exiting Self-Diagnostics & Clearing Codes

To exit self-diagnostics, turn ignition off. All codes are cleared when ignition is turned off. Fault codes are not stored in memory. Even if a code has occurred several times during a period of time, code will only be stored until ignition is turned off.

TROUBLE CODE IDENTIFICATION TABLE

Affected Circuit/Sensor Code

• 111 = Fault Free System

Outside Temperature Sensor

• 121 = Short Circuit To Ground
  122 = Open Circuit Or Short Circuit To 12 Volts

In-Vehicle Temperature Sensor

• 131 = Short Circuit To Ground
  132 = Open Circuit Or Short Circuit To 12 Volts

Water (Coolant) Temperature Sensor

• 141 = Short Circuit To Ground
  142 = Open Circuit Or Short Circuit To 12 Volts

151 = Alternator (D+ Signal Fault)

161 = Solar Sensor

Servomotor/Potentiometer

• 211 = Open Circuit Or Short Circuit To Ground
  212 = Short Circuit To 12 Volts

Servomotor

• 213 = Incorrect 12-Volt Supply To Pins No. 17 & 18
  214 = Fails To Operate Within 10 Seconds

ECC Control Panel

• 231=Faulty Temperature Control
  233 = Fan Motor Excessive Starting Current

Power Unit – Incorrect 12-Volt Supply Affected Output:

• 241 = Coolant Valve
  242 = Bi-Level
  243 = Vent
  244 = Recirculated Air
  245 = Defrost
  246 = Floor
  247 = Fan (Maximum Speed Relay)
  248 = A/C Compressor
  249 = Radiator Fan Relay

[Finnvolvo]

Thanks for replying, I wasn’t asking for the code info, but more if anyone has had the same issue as do, and how they dealt with it. Thanks

[lummert]

Is the blower motor not running? If not, the blower motor isn't necessarily the problem. The code about the blower motor starting voltage is related to the ECC power stage. More than likely the ECC Power Stage has gone bad. I installed a ballast resistor and switch to power the blower motor on my 1988 760 with ECC. Without the ballast resistor the fan ran at full speed.