How to wire the fan to a switch?

[WopOnTour]

Originally Posted by max_boost

Wouldn't it just be easier to wait until there is access to the ECM and then use that to turn the fans on when ever you wanted? Hell you've got access to the equipment and software to do it, just need to figure out how.

Try it on Rice's car first, he seems to like being the guinea pig

The problem with J1850 bidirectional communication is generally a compliant scan tool can override the PCM and switch only one single device ON or OFF. So it's not very hard at all to turn on the Low speed or High speed fans via a scan tool (and potentially even the Interceptor) but then you would still have to have the pump on a switch. (or vice versa)

Sp00ner, If you're not into all this wiring you could do what we did on a couple of cars... We bought all 4 relays (Fan1, Fan2, SP, and CAC pump) carefully pryed them open and soldered in a small jumper wire between pins 30 and 87 (the switch contacts itself) effectively turning them ON even when commanded OFF. The relays are cheap (less than $10 each) It's a bit less convenient than a switch, but it doesnt hurt to leave the fans on FULL during your lap/run. So like I said we just used a battery isolator knife switch at the battery and a booster pack or inverter while in the pits to keep er cooling down between runs. You can even leave the KEY OFF!

Just be careful if your working under the hood
AND REMEMBER TO REMOVE THE BOOSTER PACK AND TURN ON THE KNIFE SWITCH BEFORE A RUN!! (and get the booster pack recharging)

We actually forgot to do disconnect ot ONCE and the booster pack got lauched around in the trunk breaking the B+ connection and immediately killing the car He had just got onto the N2O and when the car died it finished in a tremendous back-fire! But fortunately for us, nothing was damaged.
Stupid mistakes can be expensive!!!

Wop

EDIT> lol@daughtery - Yur a riot buddy... never change- Wop

EDIT- Latest revised diagrams for ION Redline and pic of knife switch

[jpapa]

Originally Posted by WopOnTour

So like I said we just used a battery isolator knife switch at the battery and a booster pack or inverter while in the pits to keep er cooling down between runs. You can even leave the KEY OFF!

Just be careful if your working under the hood
AND REMEMBER TO REMOVE THE BOOSTER PACK AND TURN ON THE KNIFE SWITCH BEFORE A RUN!! (and get the booster pack recharging)

We actually forgot to do disconnect ot ONCE and the booster pack got lauched around in the trunk breaking the B+ connection and immediately killing the car He had just got onto the N2O and when the car died it finished in a tremendous back-fire! But fortunately for us, nothing was damaged.
Stupid mistakes can be expensive!!!

Wop

EDIT> lol@daughtery - Yur a riot buddy... never change- Wop

I may have missed the day that Wop revealed exactly what he does or why he knows so much about everything. I hope I haven't, and if I haven't, he's definetely laying some big hints as of late. Can this be some type of game show or pictionary type game where we guess the reasons of your profound knowledge?

My guess is that you're either THE know all or one of them behind the Cobalt Cup Cars with these big hints here. You don't have to say if you're right or not, especially if we're technically not supposed to know any of the stuff you're telling us (copyrights and confidentiality of it all).

And daughtery, I have decided a few months ago that it is one of my life long quests to develop a functional easy button. I don't know how to go about doing it, but that is why it will take a life time in doing so. It may involve wiring a transmitter into Wop's brain that will reveal all the answers. But here at school, I have wished every semester that we could be given the easy button on any 1 test once a semester, because engineering can really make you crumble after awhile, especially at U of Mich. It's not normal to be able to get a B in a class when you average around 40% on exams, that kind of stuff just gets to your head...

Sorry that this has been way off topic, but I just wanted to point out my observations. Good luck on the wiring there Sp00ner, it looks like you got your work cut out for you. I don't know if I could ever brave such a project on my own.

[Batman]

One rheostadt in series with the ECT should be the easiest way to do it. Dial it up when you want and make the PCM think the engine temp is much higher that it really is.
-Would not be a good idea during normal running operations since the ECT input would affect the PCM computed engine load and other parameters. But you could dial it down to zero resistance when not in use.

[WopOnTour]

Originally Posted by Batman

One rheostadt in series with the ECT should be the easiest way to do it. Dial it up when you want and make the PCM think the engine temp is much higher that it really is.
-Would not be a good idea during normal running operations since the ECT input would affect the PCM computed engine load and other parameters. But you could dial it down to zero resistance when not in use.

Yes, but that defeats the purpose. What you are proposing wont work to run the fans and CAC pump with the engine and ignition OFF.
Wop

[littlebigss]

Cooling Fan - 1 (LSJ/2.0L)
Connector Part Information

OEM: 15383305
Service: 88988311
Description: 2-Way F Metri-Pack 480 Series Sealed (NA)

Terminal Part Information

Terminal/Tray: 12191448/3
Core/Insulation Crimp: F/3
Release Tool/Test Probe: 15315247/J-35616-40 (BU)

Cooling Fan - 1 (LSJ/2.0L) Pin Wire Color Circuit No. Function
1 L-BU 409 Cooling Fan Motor Supply Voltage 2 -- -- Not Available
3 WH 504 Cooling Fan Motor Low Reference


Cooling Fan - 2 (LSJ/2.0L)
Connector Part Information

OEM: 15383305
Service: 88988311
Description: 2-Way F Metri-Pack 480 Series Sealed (NA)

Terminal Part Information

Terminal/Tray: 12191448/3
Core/Insulation Crimp: F/3
Release Tool/Test Probe: 15315247/J-35616-40 (BU)

Cooling Fan - 2 (LSJ/2.0L) Pin Wire Color Circuit No. Function
1 GY 532 Cooling Fan Motor Supply Voltage
2 -- -- Not Available
3 BK 1050 Ground


hope this helps for part numbers and such sorry for the roughness

[WopOnTour]

If it was that simple... well, wouldnt it be nice
All PCM output drivers (low or high side) will ABSOLUTELY set DTCs if the voltage observed on the circuit does not match the existing logic level. ie. if it "sees" the relay circuit GROUNDED, when it "KNOWS" it isn't providing it... CEL (and vice versa when it IS pulling the circuit to ground)
What you see in the artwork of the schematic is only a SIMPLIFIED representation and only the output portion of the solid-state ODM (Output Driver Module) -there's an input element as well.
THEY ARE NOT MECHANICAL RELAYS OR SWITCHES THEY ARE SOLID-STATE DRIVER MODULES

So what you are proposing will not work...trust me
(but go ahead and prove it to yourself and wire your car up as you propose)
Wop

[dam718]

Alright... I found what you need to do the job right Sp00ner...

here we go...

You'll need one of these relays... It's a 12V Coil, 3PDT relay (3 Pole, Dual Throw). It's only rated at 10A, but that's plenty since all we're using it for is triggering the factory relays.

http://www.circuitspecialists.com/prod.itml/icOid/6111

You'll also need a SPDT toggle from Radio Shack.

Electrical connections as follows:

SPST Toggle:

Pin 1 - Ground
Pin 2 - Pin A of Relay

3PDT Relay:

Pin A - +12V
Pin B - Pin 1 of SPST Toggle
Pin 1 - ECU Side of Pin C1-51
Pin 2 - ECU Side of Pin C1-10
Pin 3 - ECU Side of Pin C1-34
Pin 4 - Ground
Pin 5 - Ground
Pin 6 - Ground
Pin 7 - Relay Side of Pin C1-51
Pin 8 - Relay Side of Pin C1-10
Pin 9 - Relay Side of Pin C1-34

So what you'll be doing is this... Find the wires that go to each of the ECU Pins listed in the engine compartment. Don't remove them from the plug unless you really want to, but you don't need to.

Once you find the three wires you'll need to cut them all. This will leave you with 6 wire ends... Three going to the three pins in the ECU, and three more going out to the fan and intercooler pump relays. You'll probably want to extend these 6 leads so you can locate the new relay wherever you want it... So extend them however far you need them to be extended... Then follow the pinouts listed above. 1, 2, and 3 go to the ecu pins, 7, 8, and 9 go to the factory relays.

Functionally it works like this: When the relay coil is not energized, the ecu pins are routed to the relay triggers. When the relay coil is energized (by turning the toggle switch on), the ecu pins are isolated completely and all three factory relays are triggered, turning both fans on in high speed as well as starting your intercooler pump.

Turn the toggle off, and everything is back to factory wiring.

By isolating the ECU pins when the relay coil gets energized you'll prevent the DTC's Wop mentioned because the pins from the ECU will never see a ground signal.

Heh... It sounds more complex than it is I'm sure... If you have any questions shoot me a PM.

Should cost you no more than $20 in parts. Oh yeah, I hope you know how to solder...

Wop? What say you about this? Will it work if the ECU pins never see the ground signal being sent to the factory relays?

[Batman]

Originally Posted by WopOnTour

Yes, but that defeats the purpose. What you are proposing wont work to run the fans and CAC pump with the engine and ignition OFF.
Wop

You are obviously very knowledgable on this system and the whole solid state driver portion of the PCM that actuates the cooling system. I don't know about the CAC pump portion of what I am about to talk about since the control system for the CAC pump seems to not be mentioned in the FSM basic schematics.

In the system description though (page 6-572 for the 2.0L engine) it says "After the vehicle is shut off if the engine coolant temperature at key-off is greater than 284F and system voltage is more than 12V the fans will stay on for approximately 3 minutes".

I would use a rheostat in series with the ECT. The reason-
-it is a simple mod to make.
-It would only cool for 3 minutes if the vehicle was off and be a reasonable drain on the battery and not need an additional power source. In summer whether (85F assumed) with no CAC pump energized (although I am not sure this would help any thing any way). Temperatures should lower from a real value of 220 to 190F (actual calculated on is 176 but the thermostadt would start to close so 190F is a swag).
-If the engine were running it would work to cool the system just fine.

Bottom line it would really depend on the end user and what he would want but if it were me I would't want the additional weight of a battery or power source or the hassle of remembering to turn it off and not drain my battery down.

I am curious now about the CAC control system.

[WopOnTour]

Originally Posted by Batman

You are obviously very knowledgable on this system and the whole solid state driver portion of the PCM that actuates the cooling system. I don't know about the CAC pump portion of what I am about to talk about since the control system for the CAC pump seems to not be mentioned in the FSM basic schematics.

In the system description though (page 6-572 for the 2.0L engine) it says "After the vehicle is shut off if the engine coolant temperature at key-off is greater than 284F and system voltage is more than 12V the fans will stay on for approximately 3 minutes".

I would use a rheostat in series with the ECT. The reason-
-it is a simple mod to make.
-It would only cool for 3 minutes if the vehicle was off and be a reasonable drain on the battery and not need an additional power source. In summer whether (85F assumed) with no CAC pump energized (although I am not sure this would help any thing any way). Temperatures should lower from a real value of 220 to 190F (actual calculated on is 176 but the thermostadt would start to close so 190F is a swag).
-If the engine were running it would work to cool the system just fine.

Bottom line it would really depend on the end user and what he would want but if it were me I would't want the additional weight of a battery or power source or the hassle of remembering to turn it off and not drain my battery down.

I am curious now about the CAC control system.

Batman, what you are proposing isnt a bad idea- however the 3 minute "hot soak" fan cycle just isnt long enough to do enough to bring down the temps of the engine and CAC coolant. Last couple years we've PRAYED for at least 15-20 minutes between rounds so we could get temps down and stabilized prior to. I mean every bit helps, and what you are proposing HAS been done... it just doesnt last long enough to really help.

PS> The schematic for the CAC pump is in my post above. In the FSM it's located in the ENGINE CONTROLS 2.0 section. Check out "Description and Operation" in that section
Wop

[Batman]

Originally Posted by WopOnTour

Batman, what you are proposing isnt a bad idea- however the 3 minute "hot soak" fan cycle just isnt long enough to do enough to bring down the temps of the engine and CAC coolant. Last couple years we've PRAYED for at least 15-20 minutes between rounds so we could get temps down and stabilized prior to. I mean every bit helps, and what you are proposing HAS been done... it just doesnt last long enough to really help.

PS> The schematic for the CAC pump is in my post above. In the FSM it's located in the ENGINE CONTROLS 2.0 section. Check out "Description and Operation" in that section
Wop

Thanks. I have not been fortunate enough (yet) to be able to get this kind of experience.
Specific fan control system aside why can't you run the engine (idle) to 1 help cooling by running the coolant pump 2) provide air flow past the intercooler? It just seems like an extra battery to help the cooling would be more weight. Is it a fuel issue? Or do you have to shut down the engine for some other reason?