TEST 5: Bypassing The High Speed Fan Motor Relay
If you've reached this point, you have:
- Tested the amperage draw of the fan motors (TEST 1 and TEST 2).
- Bypassed the low speed radiator fan motor relay (TEST 3).
In this section, we're gonna' bypass the high speed radiator fan motor relay and see if the fan motors run.
To be a bit more specific: We're gonna' jumper female terminals 77 and 79 of the high speed radiator fan relay socket in the Power Distribution Center.
The high speed radiator fan motor relay is located in the Power Distribution Box (see illustration 1 of 2 above).
IMPORTANT: Do not jumper any other terminals of the relay socket than the ones indicated! Jumpering any other female terminals can damage the fuel injection computer.
These are the test steps:
- 1
Remove the high speed radiator fan motor relay from the Power Distribution Center (see illustration 1 of 2).
- 2
Locate terminals 77 and 79 of the relay socket (see illustration 2 of 2).
- 3
Connect one end of the jumper wire to the terminal labeled with the number 77 (see illustration 2 of 2).
- 4
Connect the other end of the jumper to the terminal labeled with the number 79 (see illustration 2 of 2).
- 5
The both fan motors should run in high speed.
Let's analyze your test result:
CASE 1: Both fan motors ran. This is the correct and expected test result.
You can conclude that the high speed circuit of both fan motors is OK if you have confirmed that their amperage draw is less than 40 Amps in TEST 2.
Now, you can conclude that the radiator fan motor assembly is OK (not defective) if you have:
- Confirmed that the amperage draw of the low and high speed circuits are under 40 Amps (TEST 1 and TEST 2).
- Confirmed that fuse 12 and fuse 23 are not blown (TEST 1 and TEST 2).
- Confirmed that the fan motors ran when you bypassed the low and high speed fan relays (TEST 4 and TEST 5).
CASE 2: Both fan motors DID NOT run. With this test result you can usually conclude that the fan motors are bad and that the radiator fan assembly needs to be replaced.
But to be sure they're bad, you need to make sure that the fan motors are getting power and Ground. Your next step is to go to: TEST 7: Making Sure The Radiator Fan Assembly Is Getting Power From The High Speed Relay.
CASE 3: One fan motor ran but NOT both. The fan motor that did not run is bad. Replace the radiator fan assembly.
TEST 6: Making Sure The Radiator Fan Assembly Is Getting Power From The Low Speed Relay
If you've reached this point, you have:
- Tested the amperage draw of the fan motors (TEST 1 and TEST 2).
- Bypassed the low speed radiator fan motor relay (TEST 3) and both fan motors DID NOT run.
In this test section, we're gonna' make sure that the radiator fan motor connector is supplying battery power to the radiator fan assembly when the low speed radiator fan relay is bypassed.
The connector that we're gonna' test is the one with the female terminals (see photo above).
The terminal that we're gonna' test is the female terminal labeled with the number 3 in the photo above.
To check for battery power at female terminal number 3 we need to jumper terminals #72 and #74 of the low speed radiator fan motor relay socket.
NOTE: This test is done on the 4-wire connector with female terminals.
IMPORTANT: Do not jumper any other terminals of the relay socket than the ones indicated! Jumpering any other female terminals can damage the fuel injection computer.
These are the test steps:
- 1
Disconnect the radiator fan assembly's 4-wire connector.
- 2
Remove the low speed radiator fan motor relay from the Power Distribution Center.
- 3
Jumper together terminals #72 and #74 of the relay socket.
NOTE: The illustrations in TEST 3 will help you locate terminals #72 and #74 of the low speed radiator fan relay socket. - 4
Place your multimeter in Volts DC mode.
- 5
Probe female terminal #3 with the red multimeter test lead.
The DK GRN wire connects to female terminal #3. - 6
Connect the black multimeter test lead to the battery negative access point on the left strut tower.
- 7
Your multimeter should read 10 to 12 Volts DC.
Let's analyze your test result:
CASE 1: 10 to 12 Volts are present. This is the correct and expected test result.
Your next step is to make sure that Ground is present at female terminal number 1. For this test go to: TEST 8: Making Sure Ground Is Present At Female Terminal #1.
CASE 2: 10 to 12 Volts ARE NOT present. This test result lets you know that there is a problem with the dark green (DK GRN) wire between the connector and the Power Distribution Center.
The most likely cause of these missing 12 Volts is an open-circuit problem in the DK GRN wire.
Your next step is to check the continuity of the DK GRN wire between the Power Distribution Center and the 4-wire connector. The following wiring diagram will help you: Radiator Fan Circuit Wiring Diagram (2001-2006 2.4L DOHC Chrysler Sebring And Dodge Stratus).
