2 wire door actuator

Hi,
I need some advice about the keyless entry on my car.
The system uses a -ve pluse 2 wire system.
The relays work ie fire when the arm disarm
The wires see - ve pluse then +ve pluse or -ve on both if probes are swapped.
One the door actuator failed so I swapped for new one. Which failed within one day!
Ok swapped old working to fault side and fitted another one actutor which has also stopped this after only 1 hour of testing and adjustment.
Any ideas?

Are your relays firing when they stop working?

Have you tested the actuators by hooking them up directly to a car battery?

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No question is stupid or not worth asking. You were once a noob, right? :)

Where are you getting these actuators?

Hi,
Yes the relays are firing - They Bosch 20A units the outputs go high - fuse OK etc.

Bought them in Maplins (equivalent to Radio Shack in the US).
They are a pistol type with 6kg torque.
The old ones have heavier cable otherwise they look identical.
I should be able to get them replaced free of charge.
I was wondering if need to add a ballast resistor to limit the current?

ninjasta wrote:

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Hi,
Yes the relays are firing - They Bosch 20A units the outputs go high - fuse OK etc.

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They are high relative to the car earth.
Between outputs relay its goes -ve The pulse length is probably around 0.5 secs. Long for meter to momentarily register - 12.57V (Batt Voltage) then fall to zero.

The Maplin units are shall we say entry level.
Make sure they have an easy mechanical run, something impeding them will burn them our.

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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.

The car is a 1977 Triumph TR7.
Having played with door locks door have mechical interlock that prevents the door locking unless it is either closed or the door open handle is lifted.
i not sure whether one or more doors. However the push rod was not tightened meaning it would slid up and down unimpeded. I was firing the locks to the movement range when I the second failed. So that shouldn't have been a problem.

That's the standard European door lock interface so you can't lock yourself out.
The way to test is to throw over the catch or pawl at the lock then you've emulated a closed door.
What you've done is to give your motors a tight run and that's why you're burning out the motors. Set it up so the action is free and easy then you'll have no problems. You've done nothing wrong electrically.

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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.

How long and how often are you firing these actuators for. They should be robust enough for any kind of typical usage even if they can't move e.g. lock a door that's already locked. Excessive use i.e. testing can burn them up much like a starter. Starter is great under normal conditions, short bursts to start the engine but if you use it abnormally like when your car won't start and you keep cranking it it'll live a very short life.

I seem both sides working now. The original instsall in mid 1990's was done with the alarm. They put actuators vertical with rods at -30 dregs or so to actual latch rod from the button. Although this worked it hozontal force on the when firing.
So having googled how they should be mounted. I have relocated them to suitable position push/pull at the angle as the buttons. Added some heat shrink tubing onto the the button potentially catching on edge it's hole. Refitted a clip thingy I found in bottom of the door that secures the bottom latch rod to lock lever