MES Central Locking System

Alright, I ran a search and didn't find any answers so I really hope that this isn't a duplicate thread.  If it is, please be kind enough to link me to the thread that has the correct answers.  To keep me outta hot water, the vehicle is a 1978 Ford F250, but I'm doing a complete re-wire.

Okay, first problem to tackle (and I think I got it figured out) is that I am rewiring my truck with the new ISIS multiplex wiring system.  Pretty cool system.  Anyways, one of its major limitations is that it can only output a positive signal.  For the "actuators/reverse polarity" system diagram, this doesn't work.  Quickest solution I can see is to just ground the coil terminals instead of feeding them +12V.

Which brings me to my first question.  Does anyone have a wiring diagram or pinout chart for an MES central locking module.  I'd like to know how that thing works inside because I thought of maybe just reversing the positive and negative leads that feed the module.  This would allow a positive pulse to actuate the system.  The only problem I see is that instead of having both actuator legs resting at ground, I believe they would be resting at +12V and one leg would be pulled to ground to actuate.  While this is a sound theory, I don't like the idea of having these constant hot +12V wires running through the truck, itching to start a fire.

So, this leaves me with using my own relays.  Which is fine.  Both actuators up front are of the 5-wire variety.  Can someone provide a pinout or wiring diagram for the actuator.  I know there are the two actuator control wires, but what do the other 3 do?  I know they somehow signal the system that a lock knob position has changed, and this makes them master actuators that control the slaves.  But how?  I'm serious, a wiring diagram would be the best.

I've scoured Google for countless hours trying to find a wiring diagram, but everything I find just says "plug into the provided harness".  That's swell and all, but what in the hell does the harness do?  Say I didn't have a harness, what would I do?

Thanks in advance for all the help.

Okay, I found this:

https://www.mycyclops.com.au/docs/4CL-001%20Installation.pdf

If you go to the last page, it has the wiring diagram.  It was kinda what I suspected.  However, this brings up another question for me.  Are the brown white and black wires all "tied" together?  For example, if you pull up on the lock switch, does it connect the white and black wires together?  The reason I ask is because, again, I have to use positive triggers to activate (ISIS wiring).  The diagram shown gives negative pulses when manually manipulating the lock knob.

Am I correct in assuming that if I were to hook the black wire to +12V, I would get positive lock and unlock pulses on the brown and white wires when using the lock knob?

howie ll wrote:

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The MES relay is negative triggering only. It's NOT two separate relays, it's a double with a timing device, I'll explain that further on. Unfortunately the way it's wired, you can only activate it with NEG switching. From your colours I don't think you're using MES actuators (they are the best) because you mentioned black brown and white. These colours are I think purple, brown and black with MES.  Simply these are the switching wires, the motors are blue and green. With MES the motor wires are blue and red.  Now with the switching wires, black is a constant ground and either the white or brown get connected when pushed or pulled.  Because they are constanlty connected in either state, that's why the MES relay shuts off after about 1-3 secs. The suggestion in your previous post is correct.  ISIS to 86, ground to 85 and 30, 87 to MES relay. That's the only way it will work.

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Howie:

Thanks for the info.  I do have an MES system, but I don't have it in front of me so I just used the wire colors on the diagram I had the link for.

Now, my question still remains tho.  Could you not just reverse the power and ground wires that feed into the MES central locking module?  From my research, this would basically just reverse the polarity of every wire in the whole system.  Thus, the black wire would constantly be connected to either the purple or brown wires.  But instead of constantly being connected at a ground state, it would be connected at a +12V state.  Also, both actuator legs (blue and red) would constantly be resting at +12V (a disadvantage for the aforementioned reasons) with a pull to ground on either motor leg to lock or unlock.  This would also allow the inputs from the ISIS (positive pulses) to actuate the locking module.

Unless the central locking module itself (or some sub-component therein) is polarity-sensitive, I don't see why merely reversing the power and ground wires wouldn't work.

Let me know your opinion on this, as I do value it.

hi,

if you just need the actuators to operate without any central locking, you can wire the isis module outputs to relays (bosch or equiv).  this will give you your reverse polarity, rest at ground setup.  connect relays as follows:

term 87 and  term 86 to isis output (lock or unlock)

term 87a and term 85 to ground,

term 30 to door actuator (lock or unlock output)

repeat again with another relay ...1st relay for lock, 2nd for unlock.

m

Ween]< wrote:

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>hi,

if you just need the actuators to operate without any central locking, you can wire the isis module outputs to relays (bosch or equiv).  this will give you your reverse polarity, rest at ground setup.  connect relays as follows:

term 87 and  term 86 to isis output (lock or unlock)

term 87a and term 85 to ground,

term 30 to door actuator (lock or unlock output)

repeat again with another relay ...1st relay for lock, 2nd for unlock.

m

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Ween:

I certainly thought about this.  The ISIS module is advanced enough that I figured it could handle the chore.

I think it could even be configured to handle central locking as well.  The inputs it takes are negative ground. What I could do is wire the purple and brown wires to the inputs of the ISIS system and set the lock and unlock outputs to output a half-second pulse when they receive the appropriate input.  It wouldn't matter that the purple or brown wire would be resting at ground all the time because the ISIS module can be set up to only pulse a momentary output even though it is getting a constant input.

It might be worth trying. Still gotta use two relays, but then again, there's no way to do it with less than two (if you count the MES module as two relays).

Comments?

having dealt a little with the ISIS pieces, i'd forgo the MES system.  still use the five wire actuators having the switch contacts trigger your inputs to the ISIS.  the ISIS then controls the outputs for 'x' amount of time.

m