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Discussion Starter #1
Ok.

I was seeing what it would take to add a “Cooling Fans On” switch to my 06 Elise. (I know if I turn on the AC it will turn on the fans but I don’t always want to do that)

I looked at the wiring diagram, page 11 “A/C Control Module” (http://www.kold-fire.com/images/EliseWiring.pdf), and think I would need to add a switch to connect wire 363 to ground.

I think I found the unit in the car, passenger side front under the access panel near the fuse box (part number YWB 100800).

Now I need some help calibrating my decoder ring.

On the wiring diagram wire 363 is labeled 363, US, 0.5. I am not sure if US is the color code and if it is what color US would be.

On the 100800 unit it has two connectors. One has 7 heaver gauge wires (bigger wire)(on a 8 pin connector) and the other one has 5 lighter gauge wires (on a six pin connector)

Is 100800 the “A/C Control Module”? Search on this site makes me think so.

Does it make sense that grounding wire 363 would energize the Cont. Relay 3. Sending 12 V’s through the fans.
I am assuming that 363 is one of the light gauge wires but….
Is it the Green, Blue, Blue/Yellow, Green, Blue/Black?

Any ideas?
 

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The fans are arranged in such a way that they can run slow (in series) or fast (in parallel). Presumably you are looking to have them run fast.

You would ground circuits 364 and 363. These wires are available at the A/C Control Module or at the ECU vehicle side connector on pins LJ2 and LJ3.

U = Blue
Y = Yellow
S = Grey (Slate?)

So that would be Blue/Yellow and Blue/Grey
 

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Discussion Starter #3
WhatsADSM, you are it!

U=Blue. Makes me like the Porsche's wiring diagrams better.
 

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May I ask why you want an override? The fans are controlled by temperature in the non AC mode which is initiated by the ECU. What purpose is there in having the fans on when the ECU (temperature) does not call for them to run?
Michael
 

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Discussion Starter #5
I occasionally drive the car at the Golden Super Cruse, The Golden Super Cruise, and it would be nice to be able to be preemptive and turn the fans on early, in stop and go traffic.

Grounding the Blue/Slate (black) wire didnt turn the fans on.
 

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I occasionally drive the car at the Golden Super Cruse, The Golden Super Cruise, and it would be nice to be able to be preemptive and turn the fans on early, in stop and go traffic.

Grounding the Blue/Slate (black) wire didnt turn the fans on.
Slate is Grey (at least according to Lotus).

You need to ground the Blue wire with a grey stripe.

That would cause the fans to operate in the slower setting.

If you ground the blue/grey wire AND the blue/yellow wire they will then go into the fast setting.
 

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This is good stuff since my fans do not work at all,not even when I turn theAC unit on. I have replaced the relay with a new one and no joy, so this is very helpful for me to trouble shoot the problem
 

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Discussion Starter #8
OK, seems like a good time to ask

WhatsADSM

Do you have a list of all of Lotus's wire color codes?

the u = Blue, s = Gray is just not intuitive
 

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B = Black
G = Green
K = Pink
LG = Light Green
N = Brown
O = Orange
P = Purple
R = Red
S = Slate
U = Blue
W = White
Michael
 

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Discussion Starter #11
Thanks Michael -aka SirLotus -aka Viper -aka Good Guy
 

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Discussion Starter #13
I was thinking just wire 363 as all I am doing is using it for stop and go air flow.

If I just use this wire, the ecu will decide if it needs to be low speed, (default because Control Rely 1 & 2 in the non energized state so the fans will run in series) or high speed (because CR 1&2 are energized and the fans run in parallel).
 

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A single pole(SP) switch for low speed or a double pole (DP) for high speed is required.
Michael
Agreed.

I was thinking just wire 363 as all I am doing is using it for stop and go air flow.

If I just use this wire, the ecu will decide if it needs to be low speed, (default because Control Rely 1 & 2 in the non energized state so the fans will run in series) or high speed (because CR 1&2 are energized and the fans run in parallel).
The ECU outputs are open collector.

If you wire just the slow speed signal to a switch. Whenever you have your switch on it will run slow speed no matter if the ECU wants slow speed or no speed. When the ECU wants high speed (i.e. when the temps get much higher) then the ECU will ground the other wire on its own and it will automatically switch to high speed.

When your switch is off in that arrangement it will work as it did stock.

Though I do agree with Sir Lotus in that there really shouldn't be a need to do this. The ECU will deal with turning them on and off as needed and doesn't really need help. If you really have a system were you know it is going to get too hot and this is going to buy you a little extra time I would assume you want to run the full speed mode right away.
 

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Discussion Starter #15 (Edited)
Very delayed update.

I never found the correct jumpers to do the override, but I did find that:

Only one of the two fans would come on! This was because one of the wires in the fan connector in the front access area had came loose (See Pict).


Got it so both fans come on and let the car idle for 15 min and.... the heat never rose above 185. With only one fan working it would have been at 210+ and rising.

I am going to call this done... for now.
 

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Discussion Starter #17
If I remember correctly its like 205 on low and like 220 on high. (may be wrong).

The fans should come on if you turn on the AC.
 

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Discussion Starter #20
Never did do this. Found one fan was unplugged and that was my temp issue. Plugged them both in and temps with the stock rad were good.

Last weekend upgraded to a wizard "big" radiator so should be even better!
 
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