I am getting ready to install the JCW CAI, and want to put a manual override switch in, but I need some electrical help. There is a wiring harness attached to the new partition, which includes a control unit. There is a black ground wire, a red wire (with a 3 amp fuse in the middle) that goes to pin 8 of the 12 pin connector in the fuse box, and a yellow wire that you splice into the white/red wire from pin 112 of the connector with the big bundle-o-wires. This yellow wire supplies the tach signal to the control unit.

There is a wire pair with a two pin connector that comes from this harness and plugs into the electric valve mounted on the side of the airbox (which has a vacuum hose coming in, and a vacuum hose coming out that goes to the flap). This pair consists of a blue wire and an orange wire.

So, here is my plan: identify which of the two wires that goes to the valve is the +12v and cut it. Then put a diode on the side coming from controller. On the side still connected to the valve, I will splice a new wire that runs to a switch in the cockpit, and also reconnect it to the diode. I will then splice into the red wire from the control unit (on the load side of the fuse), and run it into the cockpit for the other side of the switch.

Does this make sense? Will it work? Any suggestion on the specs for the diode?

 

Anyone?

 

Are you wanting to basiclly put a opened, closed switch on? The flap is activated when a certain voltage, Amp is reached in the circuit it is connected to.

 

I'd do it a bit differently... Use a double pull double throw switch. The bring the control wire to one side of one of the pulls, and +12 to the other side. Send the signal out the center of that pull. Take the +12 to the center of the other pull, and you can use some 12V lights or whatever as an indicator of position for the unit (lights are cool). This will avoid the diode drop in your plan, and get an indicator as well! But the diode drop probably isn't a problem, so your plan should work. You can use a double pull switch in your method as well to switch and indiactor, or get a lighted switch.....

Matt

 

The flap is activated when the controller sees a 150hz 12v signal on the yellow wire that is tapped into the tach signal, then it sends +12v to the valve that allows vacuum to the flap.

 

When you say "bring the control wire" are you talking about the yellow wire that taps the tach signal? And when you say "+12 to the other side" do you mean from the +12 that is supplying the controller or taking it from a circuit inside the cabin? Why use a DPDT? Wouldn't that give three positions for the flap: 1) normal JCW flap function; 2) no flap activation; 3) always open flap? My plan was to use a lighted (when on) rocker in the knockout next to the e-brake, with only two postions: 1) normal JCW flap function; and 2) always open flap.

Forgive my many questions, I am an electrical newbie. Can you draw a diagram of what you are suggesting? Thanks for your help.

 

OK, can I just cut the +12v going to the valve and send the line side to the "A" terminal of a SPDT, send the load side to the COM terminal, and tap the +12v from the controller and send it to the "B" terminal of the SPDT?

Hmmm, would this switch be lighted in the "B" position, but only lighted in the "A" position when the flap is triggered by the controller? That might be cool or annoying.

 

SPDT is a single pull, double throw. This means there is only one item that is switched between two positions. So if you have three connections on it, A, B and C, you have A-B or A-C connections.

DPDT is a double pull double throw. Just the same as above, but with two circuits in parallel

So A1, B1, and C1, A2, B2 and C2. You can have A1-B1 with A2-B2 or A1-C1 with A2-C2. A lighted single pull switch will work just fine as well.

What you suggested (using a diode and a single pull single throw) will work as well, is just gets a voltage drop of about 0.3-0.7 volts across the diode. No big deal, but there.

Sorry, no sketches, my gallery is full.

Matt

ps, to learn more about electronics, get Horowitz and Hill, "the Art of Electronics" -M-

 

What? Did you mean SPDT? edit: you couldn't have meant SPDT, now that I re-read your post, so what do you mean?

 

I would just remove the flap altogether and not worry about connecting the activator. This is exactly what John Cooper Garages did and they even sold them this way on their website. So, in some sense, this is an "official" JCW mod.

They also made a little blanking plate to cover the hole at the top of the inlet. That site is no longer up so I don't have pictures or links handy.

 

really depends on the switch you choose. It's just another switch circuit in parallel with what you're doing. Read the documentation of the switch to see how it all works, but they also require a return to ground. So that's another wire.....

Matt

 

Thanks Dr O. When you were suggesting the DPDT switch, were you suggesting using one set of contacts to interrupt/activate the tach signal and the other set to activate/interrupt the "new" 12v supply? Thus, when the switch supplied the 12v, it also disconnected the tach signal, and vice versa?

And just a side note on the vocab: the "P" stands for "Pole" not "Pull."

 

I was suggesting one part of the switch to control the vacuum solenoid, and one to control external indicator lighting.

Matt
" ____________ from JCW Control
" /

" To Vac Solenoid___/


" \___________ +12 volts


" __________ Normal Operation indicator
" /

" +12 Volts________/


" \__________ Bypass indicator



These are the two halves of the linked switch


crap... this site took out all the leading blanks... I'll see if quotes fixes it.. Nope. Can't make a picture...

But if this doesn't make sense, just use your diode and a SPST switch to put the 12 volts in past the diode... It will work.

 

Ahhhhh, I see what you are saying: cut the 12v wire supplying the solenoid and run the line side to the top right contact in the the above drawing and run a new constant 12v to the second contact down, and run the top left contact to the solenoid (load). Then run 12v to the bottom right contact and wire a light to the bottom left contact. Cool.

Oh, I could run two lights, one for each position if I run 12v to the bottom left contact and one color light to the third contact down on the right, and another color light to the bottom right contact. Too blingy? LOL!

Or I could rely on a rocker with two lights on it:

 

That's it!

But really, all it does is avoid the diode drop and give you lighting options.

Matt

 

So, is the goal here.....
Switch Position 1: normal JCW flap operation, open only above 4500rpm
Switch Position 2: always open
That seems like a cool upgrade. Is someone going to piece together a how-to on this one? That would be most appreciated!

Thanks.........

 

That was the original goal. The options on the table now are as follows:

- Switch with three positions (Normal JCW/Always closed/Always open)
- Lighted switch that lights in Always Open position
- Lighted switch that lights in Always Open position and lights when flap opens under Normal mode
- Indicator light(s) to take the place of the lights on the switch

I am not sure if I can get to it this weekend, but I will document the mod when I do it and post the details/pics when done.

 

Thanks for taking the time to document with details and pics, awesome.

However, I am confused on the need or want for indicator lights to replace the light in the switch? Also, where are you planning to mount the switch and indictor lights.

I will be happy to compare notes, as this s a must have upgrade.

Thanks Again.........

 

Was unable to get to it this weekend, shooting for next weekend.

The indicator lights would be in lieu of a lighted switch if I can't find one that fits in the knockout to the left of the parking brake. I am hoping to find one that fits with little or no modification.

 

most lighted switches are too big for that location. And the knock out comes forward, so larger switch bodies won't work, as they don't fit through the hole.

For indicator, you can use a multi-color LED. They make bi- and tri-color LEDs, then you just have to remember what color is what!

Matt

 

Minut:
Did you complete the install and DIY write-up? Where did you finally mount the 3-position switch and the indicator lights?

 

Waiting for some warranty work to be completed before I do it.

 

Hey Minut:
How is that warranty work coming along? More importantly, how is that DIY write-up coming along?

Thanks.........

 

I drive more cars than Leno. Unfortunately the dealer doesn't rent or lend me any that look like they came from his collection. All mods on hold until I get my car back in working order from the dealer.