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Automatic rear spoiler project

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BibaResto

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I have to admit what reading I've done, this group doesn't seem to be car folks, but hopefully wrong.

I'm breaking all of the rules as a newbie, so please bear with me.

I admit I know nothing about electronics. But I'm looking for someone who is interested and feel's they could come up with a more elegant solution to my spoiler problem.

Chrysler Crossfire's (XF) Base and Limited cars (made by Mercedes Benz) all have electronic spoilers. The top of the line SRT-6 gets a static bulky Spoiler.

I just bought a XF SRT-6 which I'd like to switch out the spoilers. Apparently a fairly simple fix can be made to the spoiler to make it go up and back down by holding down on a SPDT switch for several seconds. What concerns me is in the service manual it talks about 5V. The 'simple fix' would have 12V going directly to the motor.

On the electronic spoilers they automatically raise at 62 mph and retract at 39 mph. There is a switch on the dash which will raise and lower the switch if going less than 63 mph.

I'd be happy if I could use an original spoiler dash switch which I'm told only sends signals (no heavy lifting, so to speak). My absolute ideal would be to have the spoiler function just as the Ltd/Base cars do. Along with a functional original dash switch that raises and lowers the spoiler.

I could live with just the switch providing it is an original one and goes up automatically, though it needs to be held down to lower.

I'm fully aware that this post is very arrogant but hopefully someone very knowledgeable in automotive electronics, would be willing to 'take this project on'. I have a complete spoiler and dash switch for starters.

Yes, of course, I will pay you for your efforts.
 

ClydeCrashKop

Well-Known Member
Most Helpful Member
Welcome BibaResto

Your project is not out of line here. In fact, it is very similar to the many threads here on automatically opening and closing chicken coop doors. (HaHa) You should search here for that.

The DPDT switch on the dash is no problem. You need limit switches to stop the motors at the ends of their travel.

DPDT switch.jpg
As for the 5 volts, post any wiring diagrams you have. Do you know how you are going to detect 62 MPH and 39 MPH? We can do that but we need more info.

Edited to replace a wrong switch wiring picture.
 
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RODALCO

Well-Known Member
Recheck that drawing, that one will not work as both motor terminals are on the positive.
 

spec

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Hy BibaResto,

There are quite a few petrol heads on ETO- your post is fine.

I see you are from the US- which State?


Any chance of some images of your car and the spoiler?

spec
 

dr pepper

Well-Known Member
Most Helpful Member
Also beware that depending how big this thing is at 60mph the force might be substantial, you'd need something way more powerfull than a wiper motor to shift it, more along the lines of a power jack.

I share rodalco's opinion on the schematic, however the pictogram looks correct, at least on dpco switches I've used before.
An electric window switch might do the trick, some have an auto position, usually just a circuit breaker, when the window hits the top amd stalls the motor the circuit breaker in the switch clicks back to the central position.

Oh yes welcome here.
 

ClydeCrashKop

Well-Known Member
Most Helpful Member
Sorry guys. That drawing was wrong. I found a better one.
 

BibaResto

Member
Wow! I really appreciate all of these replies. I have the 2007 Chrysler Crossfire service manuals (three volumes) which total five inches high of very thin paper. There are various locations for the spoiler information - none that I've found that even mention 62 mph up and 39 mph down. And I believe there is only one voltage given of 5 volts - most everything disappearing into the black hole of the BCM. I'd say that there are roughly 28 or so pages that the spoiler is mentioned or is the sole item on the page. Regarding the limit switch it says, "Rear Limit Switch - Rear of Vehicle." Pretty helpful, eh? I assume that it is located in the PTC which is in the trunk floor. Unfortunately my scanner, which is two inches from the computer, can not be located. So I'll use my digital camera and send a few photos. Regarding the underside of the loose spoiler you'll notice it is quite small - 29 inches wide. The yellow item is the motor, to the right is the gear-box. I do want to point out that even though I'm sending information regarding the BCM, I'm quite sure this 'project' has to be a completely separate unit. IF it could be made small enough to fit on/in the area next to the gear-box that would be very helpful. I have no idea if the images I've included are helpful or not. Titles of diagrams: A - Rear Spoiler Inoperative; B - Rear Spoiler Switch Sense Circuit; C - Spoiler Limit Switch Failure; D - Spoiler Switch Led Circuit Short To Voltage (the latter asks if the voltage is above 5 volts).
 

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BibaResto

Member
By the lack of any responses, I'm guessing that this project might not sound as fun as you imagined

I have to admit that the automatic opening and closing part for the spoiler might be difficult. Would a Hall Effect wheel sensor work?

I live in SoCal and restore vintage Alfa Romeos for a living (www.BibaRestorations.com). The two client cars in the shop at this time each have eight fuses and two relays. A few less than on the XF. I'll send photos later today of the both types of spoilers.
 

spec

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Hy BibaResto,

Not lack of interest I wouldn't say- we just need some thinking time. :)

spec
 

ClydeCrashKop

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If that is the whole unit, it looks like it doesn't move very far.
Do either one of those labels say what voltage the motor is?
Are limit switches part of that assembly?
Does it look like there are any circuit boards on it or just motor, wires & switches?
 

ClydeCrashKop

Well-Known Member
Most Helpful Member
To avoid getting too complicated with microcontrollers...
A Yanmar magnetic tach sender is mounted close to the teeth on the flywheel ring gear. It puts out an AC voltage that increases with speed. At high RPM, I think it was 18 volts.
If your car has anti-lock breaks, there is a disk on each wheel that looks like a gear. If you mount a magnetic tach sender close to the teeth on that gear you will get a AC voltage that increases with speed. If you make it DC with a rectifier and smooth it with a capacitor, a comparator can turn on when your signal matches a reference voltage. BUT, the signal can't go above your 12 volt supply voltage. That ABS disk won't pulse as fast as a flywheel but you need to test it.
If when reducing your speed, the spoiler retracts before you want it to, then you will need a "window" comparator.
This little module will make things easier for you.

Comparator module.jpg

http://www.ebay.com/itm/DC-12V-30MA-1-Channel-Voltage-Comparator-Module-LM393N-LM339-IC-Chip/182046038204?_trksid=p2047675.c100005.m1851&_trkparms=aid=222007&algo=SIC.MBE&ao=1&asc=20131003132420&meid=aa7ff85a74af4be4919761d528f18cfd&pid=100005&rk=5&rkt=5&sd=251766796824

DC 12V 30MA 1 Channel Voltage Comparator Module LM393N LM339 IC Chip

Function:

1. Enter a voltage and the reference voltage contrast on the module (The reference voltage can be set by an adjustable electrical overcast), When the input voltage is greater than the reference voltage, Relay closed. When the input voltage is less than the reference voltage, Relay does not operate
2. Respectively inputted two special Compare Voltage signal 10 and 12, When the voltage signal 12 is greater than voltage signal 10, Relay closed. When the voltage signal 12 is less than voltage signal 10, Relay does not operate
3. Enter a voltage and the reference voltage contrast on the module (The reference voltage can be set by an adjustable electrical overcast),When the input voltage is less than the reference voltage, Relay closed. When the input voltage is greater than the reference voltage, Relay does not operate (opposite with function 1)
The reference voltage: The reference voltage of the module is the input voltage obtained through precision resistor divider, It determines the range of input voltage reference voltage, For example, the input voltage is 12V, then the reference voltage can be set in the range of 0-12V.

Operating voltage: DC12V
Sender comparator.jpg

Spoiler control.jpg
When the comparator energizes the DPDT relay the motor raises the spoiler until the up limit switch opens, stopping the motor.
When the comparator de-energizes the DPDT relay the motor lowers the spoiler until the down limit switch opens, stopping the motor.
http://www.midtronics.com/shop/products-1/integrated-solutions/midtronics-magnetic-pick-up-sensors


Other members are welcome to critique / refine this.
 
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KeepItSimpleStupid

Well-Known Member
Most Helpful Member
Damn, I lost my post. Let's try again.

The pics don;t tell us much, Likely there are 5 wires. 2 for the motor and 3 for the switches and the switches are mechanical. You do need to determine how the switches are wired and if they are open or closed at each limit. So, the connector wiring would help. Two SPDT switches would be ideal.

The BCM sees logic inputs or low current inputs. The BCM COULD do independent over current protection if the limit switch failed. There could be a PTC mounted on the motor for failure protection as well.

This is very similar to the "chicken coop door" problem. In this case two SPDT relays are wired such that the C terminals are connected to the motor and the NC terminals are nals to pass.connected to ground. This effectively grounds the motor when the relays are off. The NO contacts go to +12. This gives you one relay that controls UP and one for DOWN.

The limit switches directly allow the UP/DOWN signals to pass. We can convert the commoned limits to activate a tiny 12 V relay to re-create the independent SPDT contacts.

So, it could be as simple as 4 relays, 4 diodes and a switch. If you were doing multiple ones or wanted to miniaturize it with more protection, you could use an H-bridge IC and some logic.

The speed thing could get messy. Early speed sensors were a switch driven by the speedometer cable. All sorts of technologies can be used now from querring the OBD connector to whatever or adding your own independent sensor to the driveshaft,
 

shortbus=

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Most Helpful Member
The BCM sees logic inputs or low current inputs
Since his car didn't originally have this, I have my doubts that the BCM will be able to control this spoiler. And since the last Crossfire was model year 2008(build year 2007) the correct BCM is probably not easy to find.
 

KeepItSimpleStupid

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My point: Logic levels which basically means an interpretation of low currents, much lower than the motor.

When connected to the BCM, you are likely dealing with TTL logic levels.
 

KeepItSimpleStupid

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Info you need to find out:

Diagram C:
I can;t tell what the switches do at each extreme. Do they open or close at the extreme?

Diagram A
1. What's the value of the resistor?
2. I assume that this is the switch you want to use?
3. Is the switch momentary? Both positions?
4. How long does it take for the spoiler to move from one extreme to the other approximately?

So, what I see is it's easy to do with an UP/DOWN switch.
Harder to do if the switch in diagram A is two position.
Harder yet to do if the positions are momentary.

Automatic is harder yet.

I suspect that the OEM runs the motor for a specific time while monitoring the limit switch upon recept of a "pulse".
 

KeepItSimpleStupid

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Most Helpful Member
http://www.fuelairspark.com/fas/efi-components/xfi-driveshaft-speed-sensor-kitshtml

doesn't give you enough info to interface to the sensor directly. It would have to be a magnetic reluctance sensor or hall effect sensor. Hall effect requires a lot less interfacing.

The non magnetic ring would mount on the driveshaft (say 3 set screws) and a 2 pc collar with two magnets. The system has to be symetrical inertia wise.

A hall sensor could be this http://www.elensrl.it/en/products/s...l-effect-speed-and-direction-sensors-2/codes/ one as an example.

It's "a technology" used to obtain speed data. The native car sensor "might" be able to used.

You "could" possibly interrogate the car directly. See http://www.obdsol.com/knowledgebase/obd-software-development/reading-real-time-data/ and not interrogate it if the IGN power isn't activated or the hand brake is on.

So, right now, I'm feeling out options. It's not necessarily something I personally could do.
 

KeepItSimpleStupid

Well-Known Member
Most Helpful Member
 
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KeepItSimpleStupid

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Most Helpful Member
There is a very good chance that this module: https://racelogic.support/@api/deki/pages/book/Racelogic Limited Book 18 May 2015.pdf?origin=mt-web&stylesheet=default&showtoc=true&pageids=1563,1564,1566,1567,1569,1568 will do 90% of what has to be done.

Here's the modeule: https://racelogic.support/01VBOX_Automotive/04Modules_and_accessories/CAN_to_Analogue_Module


It can get the speed sensor data and output logic signals based on speed. I think stuff is missing, but it is a really good start if it would work for your vehicle.

A small micro like the PICAXE (www.picaxe.com) with some glue logic or direct logic in general.

The important thing, is that I researched the fundamental requirements: speed sensor and speed set points and ended up here.

I still need to understand the spoiler interface and switch arrangement.

So, you have automatic raise at 63 and lower at 39 MPH. That could be easy with the above box.

The ability to manually lower and raise below 63 MPH with a momentary OEM switch is probably harder. If, for safety, say the motor turns on for 10 seconds, then that could be harder yet. An H-bridge for the motor would eliminate relays.
 

bountyhunter

Well-Known Member
Welcome BibaResto

Your project is not out of line here. In fact, it is very similar to the many threads here on automatically opening and closing chicken coop doors. (HaHa) You should search here for that.

The DPDT switch on the dash is no problem. You need limit switches to stop the motors at the ends of their travel.
My old 1967 Dodge Charger had those to stop the headlight assemblies from rotating after they rolled up. Kind of risky, switches fail then the motors burn out because they don't cut off (just keep running). Better to have circuitry to monitor motor current (over time) and shut the power off if the current gets too high for a specific time interval. Might also use a 555 timer circuit to enable the power relay a specific time to raise the spoiler.
 
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