mercedes 2003 sl500 r230

Need to install a keyless entry system as the factory remote keyless system is broken and very $$$$ to repair (think $2000+)

Locking pump exists in left rear of trunk, but need to know:

1) Wire colors for lock & unlock (and common if necessary)
2) What type of system is this (rev. polarity, negative, positive, etc.)

Also, I understand that arming/disarming the factory alarm happens by locking/unlocking with the factory key. Want to ensure that whatever I install does not change the state of the alarm if possible (just simple locking, no arming/unarming)

Want to make sure I don't arm the factory alarm as there is no way to disarm it (due to aforementioned factory keyless entry issues). If this gets armed, the car gets bricked and becomes a worthless lump of steel :( :(

Can't I just tap the lock/unlock buttons at either the existing interior switch (on the dash) or at the lock/unlock pneumatic pump in the trunk?

Thanks!

Far as I know it's data and the only way to control the locking is to get inside the vacuum pump and 5 wire the pumps motor wires.
Enjoy.

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Amateurs assume, don't test and have problems; pros test first. I am not a free install service.
Read the installation manual, do a search here or online for your vehicle wiring before posting.

Can anybody sum up in as few words as possible, why Mercedes uses a vacuum pump to control door lock actuators?

In high school I remember reading some of my first remote start install manuals and coming across Vacuum Actuated Door Locks and thought to myself "WTH?????????" 13 years later I am finally curious enough to ask and stop assuming. (I never worked with them)

Thanks
Sorry for the Sidetrack.

Oooh I actually know the answer to that! :)

I have lots of MB experience, but not a lot of 12v wiring experience. So since you guys are helping me out, I can answer the MB questions.

MB's logic was:
1. Completely quiet (pump is in trunk, can't hear it from the car)
2. Security (if you break into the car, you can't open the trunk)
3. Safer in an accident without a metal actuator, wiring, and other metal parts inside the door. They used a plastic plunger and a few "bendable" brass rods. The idea is that in an accident everything would collapse rather than injuring the occupants.

I suspect #1 was the primary reason, but knowing MB, #3 would have played a part somewhat also.

It has always seemed odd to me to run vacuum lines into doors and through a car etc. for that purpose. I agree with #1 but I think #3 is a bit of a stretch.

My last car had the windshield wiper fluid reservoir in the trunk for both the front and rear wipers and that surprised me enough they would run washer solvent that far. I guess its not too far off from vacuum door locks...

Thanks for clarifying though and mostly satisfying my curiosity.

Not a problem with running air lines through a car, the only problem being body shops doing poor repairs and leaving the pipes off!
Remember the actuators were simply valves and rarely went wrong. I've only ever changed one.
Audi and some VW used the system as well.
The only problem with a KE is of course you won't be unlocking the trunk.
Ref: The pump, when you take it apart the motor and its wiring are in the flat base, DO NOT remove any air pipes unless you tag them!
Oh the joys on pre 95 setting alarm lock and unlock times to 3.5 seconds.

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Amateurs assume, don't test and have problems; pros test first. I am not a free install service.
Read the installation manual, do a search here or online for your vehicle wiring before posting.

Silly me, why didn't I check, Audiovox lists ORANGE lock, BLACK/ BLUE unlock, both NEG.
If that's the case after testing, I bet if you extend the lock time, say 10 seconds you will also close the windows.

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Amateurs assume, don't test and have problems; pros test first. I am not a free install service.
Read the installation manual, do a search here or online for your vehicle wiring before posting.

Most hatches and estates have one in the front with 2 pumps.
Placing it in the rear is probably better, less chance of damage. I've had at least one Japanese car and one C240 Benz where the front unit (beneath the inner wing behind h/lamp and in front of the wheel arch) had pump failure from corrosion or road damage.

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Amateurs assume, don't test and have problems; pros test first. I am not a free install service.
Read the installation manual, do a search here or online for your vehicle wiring before posting.

howie ll wrote:

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Silly me, why didn't I check, Audiovox lists ORANGE lock, BLACK/ BLUE unlock, both NEG.
If that's the case after testing, I bet if you extend the lock time, say 10 seconds you will also close the windows.

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Howie, where are those wires located that you're referring to?

At the central locking switch (in the dash) or at the pump itself (in the trunk)

Thanks!

Obviously at the pump, otherwise in the floor loom joining it in front of the front seats?

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Amateurs assume, don't test and have problems; pros test first. I am not a free install service.
Read the installation manual, do a search here or online for your vehicle wiring before posting.