Checking the Signal Cable To the Heater

WARNING: This page is about a different car, the 2002 Volvo C70, 2001 Volvo C70, 2000 Volvo C70, 1999 Volvo C70, and 1998 Volvo C70. However, it is still accessible from the selected car via links, so may be relevant.

Fig 1: Identifying Ignition OFF

Courtesy of VOLVO CARS OF NORTH AMERICA.

Ignition off.

Fig 2: Identifying 2-Pin Connectors And Wire Colors
Courtesy of VOLVO CARS OF NORTH AMERICA.

Fig 3: Identifying Voltage Display
Courtesy of VOLVO CARS OF NORTH AMERICA.
- Connect a voltmeter between the green cable and the black cable on the 2-pin connector to the blower fan.
- The voltmeter should read 0 V
- Start the heater by pressing the timer start/stop button (1).
Fig 4: Identifying Timer Start/Stop Button
Courtesy of VOLVO CARS OF NORTH AMERICA.

The voltmeter should read 11 V (slightly below battery voltage).

OK
Refer to Checking the Ground Lead For the Control Module .
NOT OK
Refer to Checking For An Open-Circuit

Fig 1: Identifying Ignition OFF

Courtesy of VOLVO CARS OF NORTH AMERICA.

Fig 2: Identifying Connector

Courtesy of VOLVO CARS OF NORTH AMERICA.

Ignition off
The 8-pin connector is disconnected from the control module.

Fig 3: Identifying Control Module Connector Terminals
Courtesy of VOLVO CARS OF NORTH AMERICA.

Fig 4: Identifying Voltage Display
Courtesy of VOLVO CARS OF NORTH AMERICA.
- Connect a voltmeter between terminal 5 (green cable) and terminal 8 (ground).
- The voltmeter should read 0 V
- Start the heater by pressing the timer start/stop button (1).
Fig 5: Identifying Timer Start/Stop Button
Courtesy of VOLVO CARS OF NORTH AMERICA.

The voltmeter should read 11 V (slightly below battery voltage).

OK
Refer to Checking the Fuel Pump Circuit (Including The Overheat Protection Thermostat)
NOT OK
Refer to Checking For An Open-Circuit