View Full Version : Please help me fix a fan problem


bboyferal
02-17-2012, 01:00 PM
Sup guys, as usual, all my problems are electrical, shit that I'll just seemingly never get! :bang:

The issue is a pair of front pusher fans that rest on the front of my AC condenser. I spent a weekend with a bud trying to test my fans (have to dump and remove my whole meth-injection reservoir, dump oil remove oil cooler, all just to remove the front fans). When I test the front fans with a car battery, they work perfectly. When installed, they don't. They've been installed working perfectly for over 3 years. They work off the factory wiring harness. One wire turns a rear puller, and then when the fans go to switch to "high speed" after 180 degrees (tuned that way), the front ones turn on from the other wire (they are one unit, but with two fans). I have extra fan relays brand new lying around and I switched them all to test. Nothing changed. They will not work in the car now for some reason. They will work perfectly when tested outside the car. The car will overheat without them since the one puller is not enough so I can't even take the car to a local shop.

Do you guys mind helping me troubleshoot this? Please, tell me what to do next! :(

Thanks guys.

bboyferal
02-22-2012, 03:55 PM
I was hoping I would get more responses. :(

Anyone?

I'm going to check the PCM signal to the fans one last time as best I can, but if I can't figure it out, are there any downsides to wiring the fan directly to the ignition so that they're on only when the car's on???

Homer's Uncle
02-22-2012, 05:22 PM
I was hoping I would get more responses. :(

Anyone?

I'm going to check the PCM signal to the fans one last time as best I can, but if I can't figure it out, are there any downsides to wiring the fan directly to the ignition so that they're on only when the car's on???

Here's description and operation from Alldata on how fan's work OE, before you directly wire them to your ignition you had mentioned taking car to local shop? You can remove one of fan relays and install fused jumper wire to get fans to come on long enough to drive your vehicle to local shop.

Cooling System Description and Operation

Cooling Fan Control
The engine cooling fan system consists of two electrical cooling fans and three fan relays. The relays are arranged in a series/parallel configuration that allows the Powertrain Control Module (PCM) to operate both fans together at low or high speeds. The cooling fans and fan relays receive battery positive voltage, from the underhood fuse block. The ground path is provided at G106.
During low speed operation, the PCM supplies the ground path for the low speed fan relay through the low speed cooling fan relay control circuit. This energizes the cooling fan 1 relay coil, closes the relay contacts, and supplies battery positive voltage through the cooling fan motor supply voltage circuit to the left cooling fan. The ground path for the left cooling fan is through the cooling fan 3 relay and the right cooling fan. The result is a series circuit with both fans running at low speed.
During high speed operation the PCM supplies the ground path for the cooling fan 1 relay through the low speed cooling fan relay control circuit. After a 3-second delay, the PCM supplies a ground path for the cooling fan 3 relay and the cooling fan 3 relay through the high speed cooling fan relay control circuit. This energizes the cooling fan 3 relay coil, closes the relay contacts, and provides a ground path for the left cooling fan. At the same time the cooling fan 3 relay coil is energized closing the relay contacts and provides battery positive voltage on the cooling fan motor supply voltage circuit to the right cooling fan. During high speed fan operation, both engine cooling fans have there own ground path. The result is a parallel circuit with both fans running at high speed.

L36
The PCM commands low speed fans on under the following conditions:


Engine coolant temperature exceeds approximately 105C (221F) .
When A/C is requested and the ambient temperature is greater than 10C (50F) .
A/C refrigerant pressure exceeds 1310 kPa (190 psi) .
After the vehicle is shut off if the engine coolant temperature at key-off is greater than 140C (284F) and system voltage is more than 12 volts. The fans will stay on for approximately 3 minutes. The PCM commands high speed fans on under the following conditions:
Engine coolant temperature reaches 113C (235F) .
A/C refrigerant pressure exceeds 1896 kPa (275 psi) .
When certain DTCs set.
LS1
The PCM commands low speed fans on under the following conditions:


Engine coolant temperature exceeds approximately 108C (226F) .
When A/C is requested and the ambient temperature is greater than 10C (50F) .
A/C refrigerant pressure exceeds 1482 kPa (215 psi) .
After the vehicle is shut off if the engine coolant temperature at key-off is greater than 140C (284F) and system voltage is more than 12 volts. The fans will stay on for approximately 3 minutes. The PCM commands High Speed Fans on under the following conditions:
Engine coolant temperature reaches 112C (234F) .
A/C refrigerant pressure exceeds 1710 kPa (248 psi) .
When certain DTCs set.

Good luck, Chris

LS6427
02-22-2012, 06:42 PM
I know a guy thats a wiring genius who works at a Pontiac dealership in Lauderdale. If you want his info let me know.


.

bboyferal
02-24-2012, 01:57 PM
Here's description and operation from Alldata on how fan's work OE, before you directly wire them to your ignition you had mentioned taking car to local shop? You can remove one of fan relays and install fused jumper wire to get fans to come on long enough to drive your vehicle to local shop.

Cooling System Description and Operation

Cooling Fan Control
The engine cooling fan system consists of two electrical cooling fans and three fan relays. The relays are arranged in a series/parallel configuration that allows the Powertrain Control Module (PCM) to operate both fans together at low or high speeds. The cooling fans and fan relays receive battery positive voltage, from the underhood fuse block. The ground path is provided at G106.
During low speed operation, the PCM supplies the ground path for the low speed fan relay through the low speed cooling fan relay control circuit. This energizes the cooling fan 1 relay coil, closes the relay contacts, and supplies battery positive voltage through the cooling fan motor supply voltage circuit to the left cooling fan. The ground path for the left cooling fan is through the cooling fan 3 relay and the right cooling fan. The result is a series circuit with both fans running at low speed.
During high speed operation the PCM supplies the ground path for the cooling fan 1 relay through the low speed cooling fan relay control circuit. After a 3-second delay, the PCM supplies a ground path for the cooling fan 3 relay and the cooling fan 3 relay through the high speed cooling fan relay control circuit. This energizes the cooling fan 3 relay coil, closes the relay contacts, and provides a ground path for the left cooling fan. At the same time the cooling fan 3 relay coil is energized closing the relay contacts and provides battery positive voltage on the cooling fan motor supply voltage circuit to the right cooling fan. During high speed fan operation, both engine cooling fans have there own ground path. The result is a parallel circuit with both fans running at high speed.

L36
The PCM commands low speed fans on under the following conditions:


Engine coolant temperature exceeds approximately 105C (221F) .
When A/C is requested and the ambient temperature is greater than 10C (50F) .
A/C refrigerant pressure exceeds 1310 kPa (190 psi) .
After the vehicle is shut off if the engine coolant temperature at key-off is greater than 140C (284F) and system voltage is more than 12 volts. The fans will stay on for approximately 3 minutes. The PCM commands high speed fans on under the following conditions:
Engine coolant temperature reaches 113C (235F) .
A/C refrigerant pressure exceeds 1896 kPa (275 psi) .
When certain DTCs set.
LS1
The PCM commands low speed fans on under the following conditions:


Engine coolant temperature exceeds approximately 108C (226F) .
When A/C is requested and the ambient temperature is greater than 10C (50F) .
A/C refrigerant pressure exceeds 1482 kPa (215 psi) .
After the vehicle is shut off if the engine coolant temperature at key-off is greater than 140C (284F) and system voltage is more than 12 volts. The fans will stay on for approximately 3 minutes. The PCM commands High Speed Fans on under the following conditions:
Engine coolant temperature reaches 112C (234F) .
A/C refrigerant pressure exceeds 1710 kPa (248 psi) .
When certain DTCs set.

Good luck, Chris

Thanks.

Through HP Tuners, my fans are both (the puller and the dual pusher) set to turn on high speed only at 180 degrees.

No DTC's, ECT sensor works great (monitored by a hanheld Diablosport, not the dummy gauge), this is all gonna have to be wiring... Something I HATE.

I will try my best. Thanks for the info.

bboyferal
02-24-2012, 02:04 PM
I know a guy thats a wiring genius who works at a Pontiac dealership in Lauderdale. If you want his info let me know.


.

Bro, I don't know how I'd get my car to him, since my car will start overheating at idle after about 15 minutes. :(

PM me his info anyway, please, whenever you have the time. I have a feeling I might need it just in case. lol Thank you.


Oh, is there any disadvantage to wiring the fans to just always be on? If it's only the life of the fans that are in question, then that doesn't matter since my car reaches 180 degrees RIGHT AWAY and would turn on all the time anyway and since I rarely drive the car since it's not a dd. What do you think?

LS6427
02-24-2012, 07:20 PM
Bro, I don't know how I'd get my car to him, since my car will start overheating at idle after about 15 minutes. :(

PM me his info anyway, please, whenever you have the time. I have a feeling I might need it just in case. lol Thank you.


Oh, is there any disadvantage to wiring the fans to just always be on? If it's only the life of the fans that are in question, then that doesn't matter since my car reaches 180 degrees RIGHT AWAY and would turn on all the time anyway and since I rarely drive the car since it's not a dd. What do you think?

15 minutes...holy shit......my temp needle won't even move for the first 10-15 minutes.

There's nothing wrong with them running all the time.....as long as you're system provides enough energy for spark at all rpm's.....

Were you on LeJuene road today, inbetween MIA and Opa Locka, heading south? I saw a blue T/A with an IC in the front bumper.....

.

RARON455
02-24-2012, 11:14 PM
heres the diagram straight from the GM manual,,,it helped me solve my problems..
http://i296.photobucket.com/albums/mm162/raron455/fans.jpg

bboyferal
02-26-2012, 01:30 PM
Finally got it.

Traced power throughout the fan wires, and it would always show power, line and ground...

So I started messing with the relays grounding them with a test light and wire to turn the fans on without PCM signal.

Though the fan was getting full power, it wasn't getting back to the relay since by grounding direct with a wire by the relay the fan still wouldn't turn on.

Took apart the wires and made a huge mess. I found that a connection has been connected incorrectly for like 6 years!!! It's hard to explain, but the male went in at a weird angle on the top of the female, not in the metal. So there was still current, but after years the plastic tips melted finally and though the wires TO the fans all showed full power, it wasn't making it back to the relays properly grounded.

Finally!

I hate wiring with a passion! Thanks for all the tips guys!

bboyferal
02-26-2012, 01:32 PM
15 minutes...holy shit......my temp needle won't even move for the first 10-15 minutes.

There's nothing wrong with them running all the time.....as long as you're system provides enough energy for spark at all rpm's.....

Were you on LeJuene road today, inbetween MIA and Opa Locka, heading south? I saw a blue T/A with an IC in the front bumper.....

.

I WISH my car could keep cool like that... 10 -15 minutes and I am at 180 at idle, but at least now it will stay there!!!

Nah, that definitely wasn't me or anyone I know, but what had you down this far south?