NG 900/9-3 Radiator Fan Test - Revision history

Mbcullen at 08:48, 19 November 2009

2009-11-19T08:48:43Z

Mbcullen at 08:48, 19 November 2009

2009-11-19T08:48:05Z

Mbcullen at 08:47, 19 November 2009

2009-11-19T08:47:21Z

Mbcullen at 08:34, 19 November 2009

2009-11-19T08:34:58Z

Mbcullen: Created page with '==Overview== The two-speed cooling fan is controlled from the Integrated Central Electronic Module (ICE). It runs at Low or High speed depending on the coolant temperature. …'

2009-11-19T08:34:35Z

Created page with '==Overview== The two-speed cooling fan is controlled from the Integrated Central Electronic Module (ICE). It runs at Low or High speed depending on the coolant temperature. …'

New page

==Overview==
The two-speed cooling fan is controlled from the Integrated Central Electronic Module (ICE). It runs at Low or High speed depending on the coolant temperature. There is no warning light for a faulty fan. The ICE module also controls the temperature gauge in the instrument panel. Regardless of whether the fan is cycling on low or high, the gauge will stay at 9 o'clock.

The cooling fan runs on Low when the coolant temperature is over 100C, and High when over 113C. It also runs on Low to cool the condenser whenever the A/C compressor turns on. If the fan low speed fails, the condenser will overheat. The most common reason is a burned out fan resistor. In warm weather, the fan should run briefly after engine is shut off. If the fan never comes on after the engine is shut off, the low speed circuit may not be working.

* Thermostat opening temp: 89 +/- 2C
* Fan Low speed turn on: 100 +/- 2C
* Fan High speed turn on: 113 +/- 2C
* AC disabled at: 126 +/- 2C
* Temp gauge at mid point (9 o'clock) 85-115C

If the fan resistor burns out, or if the low fan speed circuit fails for other reasons, the fan will continue to cycle on the high setting to cool the engine, but the coolant (and engine) temperature will run about 10-15 degrees C high. The fan may not run after the engine is shut off, and will not come on to cool the condenser. A/C will blow warm air or shut off completely at idle or in start/stop traffic. If the fan is not repaired and the condenser continues to overheat, refrigerant may start to leak, or the A/C compressor may fail.

===Cooling Fan Relays and Fuses===
The Low and High fan control circuits are separate from the ICE module all the way to the fan motor. The cooling fan Low (20-amp) and High (30-amp) relays are located in the engine compartment relay tray, and labeled on the lid of the box. The two fan fuses (30A and 40A) are in the same location.

===Testing===
The fan can be tested with the engine on or off (but preferrably off), by removing first the "Fan Low" relay, and putting a test lead, or a heavy wire jumper between relay socket contacts #30 and 87. A heavier than normal wire or test lead is required due to the large fan current. The fan should now run on low speed even with engine off. The same test can be repeated with the "Fan High" relay. Use Fuse Taps (from RadioShack etc.) or similar flat contacts in the relay socket to avoid damage to the socket.

===Fan Current===
To measure the fan current, put a meter set to a 20-amp range in series with the test leads, across contacts 30 and 87. It is safer to test the fan curent with engine off:

Fan Low Fan High
Engine Off (12V) 12 Amps 16 Amps
Engine On (14V) 14 Amps 19 Amps

===Fan Wires===
The fan connectors are close to the fan shroud near the battery tray. The picture at left is with the turbo BPV removed. Wire colors are as follows:
* White - fan High
* Green - fan Low
* Black - ground
* Wht/Grn - fan resistor to motor terminal

===Fan Resistor===
The fan resistor is inside a copper color tube, attached to the fan shroud, below the connectors. The resistor is a cheaply made wire-wound, ceramic-insulated type, about 0.20-0.25 ohms. The resistor is not sold as a separate part by Saab, but it can be easily replaced by a generic 50-75 watt resistor of a similar value.

[[NG 900/9-3 Fan_Resistor Replacement|Fan Resistor Replacement]]

===Simplified Wiring Diagram===

===References===
* Saab EPC 2-1770
* Haynes Ch 3, Section 5
* Haynes Ch 12, Diagram 2

@@ Line 12: / Line 12: @@
 If the fan resistor burns out, or if the low fan speed circuit fails for other reasons, the fan will  continue to cycle on the high setting to cool the engine, but the coolant (and engine) temperature will run about 10-15 degrees C high. The fan may not run after the engine is shut off, and <U>will not come on to cool the condenser</U>.  A/C will blow warm air or shut off completely at idle or in start/stop traffic.  If the fan is not repaired and the condenser continues to overheat, refrigerant may start to leak, or the A/C compressor may fail.
 ===Cooling Fan Relays and Fuses===
 The Low and High fan control circuits are separate from the ICE module all the way to the fan motor.  The cooling fan Low (20-amp) and High (30-amp) relays are located in the engine compartment relay tray, and labeled on the lid of the box.  The two fan fuses (30A and 40A) are in the same location.
@@ Line 19: / Line 20: @@
 The fan can be tested with the engine on or off (but preferrably off), by removing first the "Fan Low" relay, and putting a test lead, or a heavy wire jumper between relay socket contacts #30 and 87.  A heavier than normal wire or test lead is required due to the large fan current. The fan should now run on low speed even with engine off.  The same test can be repeated with the "Fan High" relay.  Use Fuse Taps (from RadioShack etc.) or similar flat contacts  in the relay socket to avoid damage to the socket.
 [[file:900_9-3_Fan_Test_4.jpg|thumbnail|none|Fig. 2 - Low Fan Speed Relay Socket]]
 ===Fan Current===
@@ Line 44: / Line 50: @@
 ===Simplified Wiring Diagram===
 [[file:900_9-3_Fan_Test_2.gif|thumbnail|none|Fig. 6 - Simplified Radiator Cooling Fan Wiring Diagram]]

@@ Line 14: / Line 14: @@
 ===Cooling Fan Relays and Fuses===
 The Low and High fan control circuits are separate from the ICE module all the way to the fan motor.  The cooling fan Low (20-amp) and High (30-amp) relays are located in the engine compartment relay tray, and labeled on the lid of the box.  The two fan fuses (30A and 40A) are in the same location.
+[[file:900_9-3_Fan_Test_6.jpg|thumbnail|none|Fig. 1 - Radiator Cooling Fan Relays]]
 ===Testing===
 The fan can be tested with the engine on or off (but preferrably off), by removing first the "Fan Low" relay, and putting a test lead, or a heavy wire jumper between relay socket contacts #30 and 87.  A heavier than normal wire or test lead is required due to the large fan current. The fan should now run on low speed even with engine off.  The same test can be repeated with the "Fan High" relay.  Use Fuse Taps (from RadioShack etc.) or similar flat contacts  in the relay socket to avoid damage to the socket.
+[[file:900_9-3_Fan_Test_4.jpg|thumbnail|none|Fig. 2 - Low Fan Speed Relay Socket]]
 ===Fan Current===
@@ Line 27: / Line 27: @@
   Engine Off (12V)      12 Amps    16 Amps
   Engine On (14V)       14 Amps    19 Amps
+[[file:900_9-3_Fan_Test_5.jpg|thumbnail|none|Fig. 3 - Testing Fan Current]]
 ===Fan Wires===
@@ Line 35: / Line 35: @@
 * Black - ground
 * Wht/Grn - fan resistor to motor terminal
+[[file:900_9-3_Fan_Test_3.jpg|thumbnail|none|Fig. 4 - Low Fan Speed Relay Socket]]
 ===Fan Resistor===
@@ Line 41: / Line 41: @@
 [[NG 900/9-3 Fan_Resistor Replacement|Fan Resistor Replacement]]
+[[file:900_9-3_Fan_Test_1.jpg|thumbnail|none|Fig. 5 - Radiator Cooling Fan Resistor]]
 ===Simplified Wiring Diagram===
+[[file:900_9-3_Fan_Test_2.gif|thumbnail|none|Fig. 6 - Simplified Radiator Cooling Fan Wiring Diagram]]
 ===References===

@@ Line 4: / Line 4: @@
 The cooling fan runs on Low when the coolant temperature is over 100C, and High when over 113C.  It also runs on Low to cool the condenser whenever the A/C compressor turns on.  If the fan low speed fails, the condenser will overheat.  The most common reason is a burned out fan resistor. In warm weather, the fan should run briefly after engine is shut off.  If the fan never comes on after the engine is shut off, the low speed circuit may not be working.
-    * Thermostat opening temp: 89 +/- 2C
+* Thermostat opening temp: 89 +/- 2C
-    * Fan Low speed turn on: 100 +/- 2C
+* Fan Low speed turn on: 100 +/- 2C
-    * Fan High speed turn on: 113 +/- 2C
+* Fan High speed turn on: 113 +/- 2C
-    * AC disabled at: 126 +/- 2C
+* AC disabled at: 126 +/- 2C
-    * Temp gauge at mid point (9 o'clock) 85-115C
+* Temp gauge at mid point (9 o'clock) 85-115C
 If the fan resistor burns out, or if the low fan speed circuit fails for other reasons, the fan will  continue to cycle on the high setting to cool the engine, but the coolant (and engine) temperature will run about 10-15 degrees C high. The fan may not run after the engine is shut off, and <U>will not come on to cool the condenser</U>.  A/C will blow warm air or shut off completely at idle or in start/stop traffic.  If the fan is not repaired and the condenser continues to overheat, refrigerant may start to leak, or the A/C compressor may fail.