Cobalt SS 2.0 Fan Questions.

[redhotjamedjimi]

A) First of all whats with the Fan 1 Fan 2 control?
do they work indepently at all?
i removed my fan2 relay and both fans still worked.

B) Also how would i set my tables so the fan would turn on as quick as possible and still be able to turn itself off. My fans no longer shut off once they start. Thank you.

[1290ss]

just adjust the percentage in the fan tabel to your desired speed at what ever temp you want the to come on and shut off.

[redhotjamedjimi]

Apparently that isn't entirely true. Look at my picture. Shouldnt my fans turn on at 196 then turn off between 196-192 once fans come on? My fans will continue to be on even once the ECT is inthe 170's. So what should i put my numbers at?

[PSYKOSTEVO]

This might be the table you are looking for.

[redhotjamedjimi]

that table for me is stock. At 0 there are no fans on. whats the best method fo ron at 196 and off at 192.

[PSYKOSTEVO]

Do you have the A/C on while this is happening, because that will turn fans on in its own right.

[redhotjamedjimi]

i have the ac pressure unplugged so its not from that.

no one i sanswering my questions of why there is 2 fan relays when only one is used.?

[imphat0260]

no one is answering my questions of why there is 2 fan relays when only one is used.?

Straight from SI2000. Hope this helps explain things better...

The powertrain control module (PCM) commands the fans on in either high speed or low speed, depending on cooling requirements. In low speed, both fans are turned on at a reduced speed. High speed has both fans turned on at a higher speed.

In low speed operation, the PCM applies ground to the coil side of the COOL/FAN Relay 1. This energizes the coil and applies voltage to the left cooling fan through the switch side of the relay, which is fed by the COOL/FAN 1 fuse. After voltage has passed through the cooling fan 1, it continues through the COOLSER/PAR Relay, which acts as a series/parallel relay, controlling fan speed, a ground path is given through G101. In low speed, the COOLSER/PAR Relay passes voltage to the cooling fan 2, effectively operating both fans in a series circuit. From the cooling fan 2, a ground path is given through G111.

In high speed operation, the PCM applies a ground to the coil side of the COOL/FAN Relay 1, COOL/FAN Relay 2, and COOLSER/PAR Relay. On the COOL/FAN Relay 2, the energized coil closes the switch side of the relay and applies voltage to the cooling fan 2. The energized COOLSER/PAR pulls the switch side over, providing a direct path to ground for the cooling fan 1, which has voltage applied through the energized COOL/FAN Relay 1. In high speed mode, the fans are operated as a parallel circuit with full voltage applied to each.

[redhotjamedjimi]

Wow. finally a great answer. Thank Phatness. I was searching the internet for so long trying to figure that out. Where can i read about how my electrical system is set up. I am having grounding problems somewheres or something which is making my idle voltage drop especially when fans are on with headlights. I am considering putting my capacitor 1F under the hood to help but it may just be a bad ground with my fusebox.

[imphat0260]

Wow. finally a great answer. Thank Phatness. I was searching the internet for so long trying to figure that out. Where can i read about how my electrical system is set up. I am having grounding problems somewheres or something which is making my idle voltage drop especially when fans are on with headlights. I am considering putting my capacitor 1F under the hood to help but it may just be a bad ground with my fusebox.

Have you checked your charging system? Voltage drop test? How much of a voltage drop are you seeing?

[redhotjamedjimi]

im goign to do the voltage drop thing etc i appreciate it. should fix it somehow.

[redhotjamedjimi]

My fans will not shut off once they start no matter what the desired fan % is. I have switch relays around though with same result. Wtf someone please.

[imphat0260]

Since you are pretty sure your file is not your problem, here is copy of what the service manual procedures are. Not 100% sure if its going to help, because this is for fans on all the time(key off also)...

Fans Always ON
1. Ignition OFF, disconnect the COOL/FAN 2 Relay.
2. Ignition ON, verify that a test lamp does not illuminate between the relay coil B+ circuit terminal and the relay controlled output circuit terminal.
⇒ If the test lamp illuminates, test the relay controlled output circuit for a short to ground. If all circuits test normal, replace the PCM.

3. Reconnect the COOL/FAN 2 Relay.
4. Disconnect the harness connector at the cooling fan 1 motor.
5. Disconnect the COOL SER/PAR Relay.
6. Verify that a test lamp does not illuminate between the COOL SER/PAR Relay switch B+ circuit and the relay coil control circuit terminal.
⇒ If the test lamp illuminates, test the COOL SER/PAR Relay coil control circuit for a short to ground. If all circuits test normal, replace the PCM.

7. Verify that a test lamp does not illuminate between the COOL SER/PAR Relay coil control circuit terminal and ground.
⇒ If the test lamp illuminates, test the COOL SER/PAR Relay coil control circuit for a short to B+. If the circuit tests normal, replace the COOL/Fan 2 Relay.

8. Verify that a test lamp does not illuminate between the relay controlled output circuit and ground.
⇒ If the test light illuminates, test the relay controlled output circuit for a short to B+.

8. Disconnect the COOL/FAN 1 Relay.
9. Verify that a test lamp does not illuminate between the COOL/FAN 1 Relay coil B+ circuit terminal and the relay coil control circuit terminal.
⇒ If the test lamp illuminates, test the COOL/FAN 1 Relay coil control circuit for a short to ground. If all circuits test normal, replace the PCM.

10. Verify a test lamp does not illuminate between the COOL/FAN 1 Relay controlled output circuit terminal and ground.
⇒ If the test lamp illuminates, test the COOL/FAN 1 Relay controlled output circuit for a short to B+.

11. If all circuits test normal, test or replace the COOL/FAN 1 Relay.


Component Testing
1. Ignition OFF, disconnect the affected relay.
2. Test for 60-180 ohms of resistance between terminals 85 and 86.
⇒ If the resistance is not within the specified range, replace the relay.

3. Test for infinite resistance between the following terminals:
• 30 and 86

• 30 and 87

• 30 and 85

• 85 and 87

⇒ If less than infinite, replace the relay.

4. Install a 20-amp fused jumper wire between relay terminal 85 and 12 volts. Install a jumper wire between relay terminal 86 and ground. Test for less than 2.0 ohms of resistance between terminals 30 and 87.
⇒ If greater than 2.0 ohms, replace the relay.

[Pandion]

This might be the table you are looking for.

What is it doing when you add the 1's in the table?