Community Forums

tboss619 · 02-24-2018, 03:06 PM

What do they cool and what makes them activate. I have a 2002 35U wbago..

BFlinn181 · 02-24-2018, 03:34 PM

Does the engine have a fan driven fan for the radiator? If so, the electrical fans are most likely supplemental fans to increase cooling of the radiator and any other items sandwiched with the radiator, perhaps transmission cooler, A/C condenser, oil cooler, etc. You'll have to trace the wires to see what turns them on.

hawkeye1995 · 02-24-2018, 06:35 PM

Turn on A/C, they should come on. They are there for extra cooling. Especially during hot days when A/C is used.

Soppy · 02-24-2018, 07:46 PM

They are for auxiliary cooling and can be turned on a number of ways. They can be turned on by engine coolant temperature , transmission temperature , air conditioner condenser pressure , or by turning on the air conditioner. You will have to get a wiring diagram to be sure. Tracing the wires may be next to impossible.

Full-Timers · 02-24-2018, 08:39 PM

From the manual.

The electric condenser fan(s) also assists with engine
cooling. The condenser fan(s) are mounted either on the
air conditioning condenser or on the transmission
external oil cooler. Both the condenser and external
transmission oil cooler are mounted in front of the
radiator. One large electronic fan was utilized on all
chassis prior to 2001 model year, and all chassis 15,000 lb.
GVWR or lower, or if equipped with a 6.5L diesel engine
regardless of model year. All other chassis 2001 model
year or newer will be equipped with two smaller electric
fans, see adjacent diagram. These fan(s) are controlled by
the Powertrain Control Module (PCM) and operate
whenever the dash air conditioning compressor is
operating or if the engine temperature is above 221
degrees F.

udid · 03-02-2018, 04:23 PM

Quote:

Originally Posted by Full-Timers

From the manual.

The electric condenser fan(s) also assists with engine
cooling. The condenser fan(s) are mounted either on the
air conditioning condenser or on the transmission
external oil cooler. Both the condenser and external
transmission oil cooler are mounted in front of the
radiator. One large electronic fan was utilized on all
chassis prior to 2001 model year, and all chassis 15,000 lb.
GVWR or lower, or if equipped with a 6.5L diesel engine
regardless of model year. All other chassis 2001 model
year or newer will be equipped with two smaller electric
fans, see adjacent diagram. These fan(s) are controlled by
the Powertrain Control Module (PCM) and operate
whenever the dash air conditioning compressor is
operating or if the engine temperature is above 221
degrees F.

What's is the easiest method to use/do to ensure the fan/s are working correctly?

Podivin · 03-02-2018, 04:36 PM

These fan(s) are controlled by
the Powertrain Control Module (PCM) and operate
whenever the dash air conditioning compressor is
operating or if the engine temperature is above 221
degrees F.

That sentence makes me think that if you turn on the air conditioner, and set it low enough that it needs to cool, that the fans will turn on.

Soppy · 03-02-2018, 04:40 PM

Quote:

Originally Posted by udidwht

What's is the easiest method to use/do to ensure the fan/s are working correctly?

On your P30 the fans are controlled from a relay which is energized from the PCM . The temperature sensor that sends the signal to the PCM is located on the right cylinder head close to the center. It will have 1 wire connected to it. You could remove the wire and ground it to test the fan. The ignition may have to be on and the engine may have to be running.
It is also controlled by a pressure switch on the air conditioner high pressure line.

BFlinn181 · 03-02-2018, 05:12 PM

Quote:

Originally Posted by udidwht

What's is the easiest method to use/do to ensure the fan/s are working correctly?

Jumper wires from the battery to the fan motors directly, or turn on the A/C and see if they come on. Being in FL, I'd think temperatures would allow A/C operation.

udid · 03-02-2018, 05:16 PM

Quote:

Originally Posted by Soppy

On your P30 the fans are controlled from a relay which is energized from the PCM . The temperature sensor that sends the signal to the PCM is located on the right cylinder head close to the center. It will have 1 wire connected to it. You could remove the wire and ground it to test the fan. The ignition may have to be on and the engine may have to be running.
It is also controlled by a pressure switch on the air conditioner high pressure line.

I have 1 big fan on the front of the A/C condenser (front of radiator). I'm going to replace the sensors and I believe there are (3) one on each manifold and one up top near the T stat. Which sensors do I need? Are the (2) on the manifolds the same?

Location of relay?

On Rockauto under 'Cooling system' I see...Temperature sender/sensor...(1994 Chevy P-30)

Standard replacement -

ACDELCO 213928 {#15326386} Sensor; GM Original Equipment Info

IN WATER CROSS-over; ECM; 2-WAY MALE; USE TOGETHER WITH MATING CONNECTOR PT1798

ACDELCO 2134396 {#19187357} Sensor; Professional

ACDELCO 12554145 Sensor; GM Original Equipment

Stripped Chassis

Daily driver -

ACDELCO 1551107 {#19189478} Sensor; Professional

Soppy · 03-03-2018, 07:02 AM

Quote:

Originally Posted by udidwht

I have 1 big fan on the front of the A/C condenser (front of radiator). I'm going to replace the sensors and I believe there are (3) one on each manifold and one up top near the T stat. Which sensors do I need? Are the (2) on the manifolds the same?

Location of relay?

On Rockauto under 'Cooling system' I see...Temperature sender/sensor...(1994 Chevy P-30)

Standard replacement -

ACDELCO 213928 {#15326386} Sensor; GM Original Equipment Info

IN WATER CROSS-over; ECM; 2-WAY MALE; USE TOGETHER WITH MATING CONNECTOR PT1798

ACDELCO 2134396 {#19187357} Sensor; Professional

ACDELCO 12554145 Sensor; GM Original Equipment

Stripped Chassis

Daily driver -

ACDELCO 1551107 {#19189478} Sensor; Professional

I have the AC Delco / GM part # for the sensors on mine , which should be the same as yours , but no guarantees .

10096147 , fan temp sw . located on RH cylinder head
15326386 , ECM temperature sender (controls fuel /air ratio)
25037333 , Temperature gauge sender (for gauge only)
The 2 senders can be checked with an ohm meter and should have a specific resistance depending on temperature. There should be a chart in the service manual.

The fan relay should be located under the dash near the fuse block.

udid · 03-06-2018, 12:51 PM

Quote:

Originally Posted by Soppy

I have the AC Delco / GM part # for the sensors on mine , which should be the same as yours , but no guarantees .

10096147 , fan temp sw . located on RH cylinder head
15326386 , ECM temperature sender (controls fuel /air ratio)
25037333 , Temperature gauge sender (for gauge only)
The 2 senders can be checked with an ohm meter and should have a specific resistance depending on temperature. There should be a chart in the service manual.

The fan relay should be located under the dash near the fuse block.

No manual on my end. You wouldn't happen to have the values handy eh? Much appreciated. 1994 Chevy P30 Fleetwood Southwind Storm