Quick question What do these black boxes do?

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KiwiPom
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Quick question What do these black boxes do?

Post by KiwiPom »

Found in drivers (rhd) footwell, is one an alarm? The smaller box was labelled “dave mk3”. There was a small siren under the bonnet which I removed before it caused trouble.

Larger box has 12 connections.

Three wires “fell out” of the small box connector strip and I have had to guess where to put them back.

I do not have a remote fob etc

I came across these 2 boxes after dropping a spanner down behind the fuse box, when working out how to reinforce the bulkhead behind the clutch master.
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AndyC
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Re: Quick question What do these black boxes do?

Post by AndyC »

They look aftermarket to me, so alarm system seems logical.

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Hawaiis0
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Re: Quick question What do these black boxes do?

Post by Hawaiis0 »

Looks like an immobiser set up.
Nothing is fool proof. Fools are clever!

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Excel SA
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Re: Quick question What do these black boxes do?

Post by Excel SA »

I've not seen any wiring with screw-in type connections in any car wiring I've looked at - always plugs, so pretty sure it's not standard. I don't have those items in my car either.

Neil.

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Alan_M
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Re: Quick question What do these black boxes do?

Post by Alan_M »

Something aftermarket - trace the wires and see where they lead.

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rbgosling
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Re: Quick question What do these black boxes do?

Post by rbgosling »

I have a (different) aftermarket immobiliser on my car. That uses a chip that slips into a slot on the dashboard. It works by the feed to the coil from the AB14 being diverted via the immobiliser. After it misbehaved, I simply reconnected the connection direct to the coil, avoiding the immobiliser diversion. It still operates on the starter motor, presumably in a similar manner, but for now that's still working OK so I haven't removed it.
"Farmer" Richard

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MetBlue
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Re: Quick question What do these black boxes do?

Post by MetBlue »

As others above say, definitely not factory fitment. Nothing remotely like that on my car.
Most likely an alarm / immobiliser.
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KiwiPom
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Re: Quick question What do these black boxes do?

Post by KiwiPom »

Thanks everyone, following the advice I quickly worked out the smaller box was an alarm with motion sensor, glass breakage sensor, plus connections to door lights and interior lights, so could be simply removed.

The bigger box is an immobilisor, connected to the alarm and which sadly on removal has stopped the engine starting (it still turns over). Fuel pump still ticks. Dash lights still come on. There were only two wires that I could not trace and I guess they were the wires connected to the “cut out” switch inside the immobiliser. They disappear into a thick harness behind the fuses in the drivers footwell.

I have managed to download a wiring diagram for pre ‘86 cars and will (eventually) work out how the immobiliser has (probably) disabled the ignition.

Related question……Anyone know where “splice D” is located? That looks like a “ignition switched” power supply terminal?

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Hawaiis0
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Re: Quick question What do these black boxes do?

Post by Hawaiis0 »

KiwiPom wrote:
Mon Jul 03, 2023 11:24

Related question……Anyone know where “splice D” is located? That looks like a “ignition switched” power supply terminal?
I would guess approx behind the dash as it feeds the wash wipe.

Note D is direct feed from A via White (W) wires, so look for W and you should find an ignition switched line if my plumbing is correct. Also, the W splice supplies are direct from power, unfused once the ignition relay is closed so be careful.
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KiwiPom
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Re: Quick question What do these black boxes do?

Post by KiwiPom »

I fixed the engine non starting, turns out a (white) wire had partially pulled out of a multi connector next to the fuse box, I must have disturbed it when looking for alarm wires hacked into the harness.

So, this made me realise the bigger black box with 12 connections is a central locking module of some sort, not an immobilisation unit, its possibly radio controlled as it has a black wire dangling out of it.

To confirm this I took the door cards off and yes the blue and green wires connect to a actuator inside the door, and these wires (LH and RH) were connected to the 12 pin box (until I took the door cards off I thought the blue and green wires were connected to the door lights….but could not work out why they were not powered up when the light came on).

So now I have a new issue of an unknown module, no remote key fob, and unknown actuators in the doors that prevent them being locked.

In addition I don’t know how the central locking is “supposed” to work……remotely? or just when a key is turned?

What is supposed to happen if you put 12v across the actuators? (Presumably for just a second).

Any suggestions gratefully received!

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bash
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Re: Quick question What do these black boxes do?

Post by bash »

I took my central locking off about 20 years ago and I dont miss it.

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MetBlue
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Re: Quick question What do these black boxes do?

Post by MetBlue »

A PO's "upgraded" the central locking to be remote. That is not standard.
Standard system works with actuators with a switch at each end. move one side by the key, it makes the switch and other side follows. Check out the electrical circuits. Think I have a picture of the standard actuator somewhere. If I find it I'll post later.
Tony
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rbgosling
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Re: Quick question What do these black boxes do?

Post by rbgosling »

bash wrote:
Tue Jul 04, 2023 05:46
I took my central locking off about 20 years ago and I dont miss it.

Bash
Is that because no-one will ride in your car with you?? :wink: :lol:
"Farmer" Richard

1990 Lotus Excel SE (Lilith)
2022 MG MG5 EV (not due to be a classic for quite a few years...)
2011 Nissan Leaf (Ragly - EV pioneer, must be due to be a classic one day)

KiwiPom
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Re: Quick question What do these black boxes do?

Post by KiwiPom »

MetBlue wrote:
Tue Jul 04, 2023 07:51
A PO's "upgraded" the central locking to be remote. That is not standard.
Standard system works with actuators with a switch at each end. move one side by the key, it makes the switch and other side follows. Check out the electrical circuits. Think I have a picture of the standard actuator somewhere. If I find it I'll post later.
Tony

Thanks Tony but like Bash and after managing to find a bit of info on CDL on here, includ8ngbthat it was not originally fitted (which surprised me) I am going to remove it, the actuators are only 2 wire type and effectively i dont have a control module as I have no remote fob.

The actuator on passenger side strains to lock the door (i put 12v onto it), and the driver side actuator is seized, which has caused the plastic handle to break around the lock, as someone i guess tried to force the key to lock the car.

The actuators put a little bit more strain on the door mechanism, which seem delicate enough anyway.

KiwiPom
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Re: Quick question What do these black boxes do?

Post by KiwiPom »

Just to add a little more mystery to this, now the CDL black box is removed, and the actuator levers removed so they dont rattle around after being disconnected from the unlocking rod….

The passenger side had red paint “overspray” on it, similarly to some other bits in the door, this indicates that maybe the CDL was fitted by the factory? Maybe as a “special” requirement?

My car is an ‘84 model year, export designated in vin, confusingly first registered in ‘86 in nz, it is unclear if it did some miles in the uk before being exported. Its no 1626 eg vin SCC089912EHG11626.

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