Central locking (another one)

[myfirstcar]

So, since we've owned the old L we have unlocked the doors manually from inside once the drivers door was open.

Talking to the previous owner, he told me it had central locking. It definitely wasn't working.

I trawled the net and this forum and read about dodgy conversions, dodgy wiring, dodgy motors, dodgy switches, dodgy controller units and dodgy fuses.

First I check the fuses, 12 & 17. Both good.
Next I take a visual at the plugs in the drivers door, all appear in good condition and connected.
Then the control unit, looks dry and in good condition. Just to be sure I swap it for another (random and untested) unit from another car. Still nothing.

At this point I have had enough and decide to live with it. A year or so goes by.

After meeting the guys at the 13th Southern meet I decide it needs to be sorted.

Back out with the multi-meter and I start with the Haynes wiring diagram, a magnifying glass (my eyesight isn't what it used to be) and some time. Door cards off and I bell out all the wiring and at the same time learn all the pin numbers in the door connectors and the control unit. These are not described in the manual.
Everything looks good, so out comes the fuse box.

For some reason, the live side of fuse 17 has zero volts. How?
This, according to the Haynes diagram, is connected directly to the battery.

The fix? I know it's a bit gash but I just linked fuse 16 out side (unused in my 1.6L but with permanent 12v) to the out side of fuse 17 and stuck the fuse into 16.

The result? All good, boot, fuel filler and all 4 doors lock unlock and deadlock.

Now I have some questions, is there a distribution block for the live feeds somewhere behind the dash between the battery and the fuse box?

Does anyone have a proper schematic for the control unit? The Haynes manual doesn't show enough detail and I can't figure out how it works. It looks like there is a 1 second pulse generator in there which controls either one of two relays for lock/unlock.

Lastly, does anyone have a schematic for the main 16 pin SOP IC used in my unit, a U2555B?
I have trawled many sites and can't come up with any useful info.

I did think way back that it would just be easier to junk the original unit and mate an aftermarket remote system to my motors and create my own dodgy conversion, but I never take the easy way out for anything.

[Robsey]

I have not heard of that one before.
No feed to fuse 17.?.. how odd.

I have seen other systems where fuses have been omitted from the main fuse board and fitted in the engine bay, such as the blower motor for cars with air con.
But I cannot see why a central locking fuse would be missing or moved.

I know that there were three wiring changes in the cavalier, but major fuses should be more or less the same across the model range. As said though, some idiosincracies exist for higher spec models with V6 engines or air-con. Oh and ex-police / ambulance cars can be a wiring mine-field.

For info, the wiring changes occured as follows: -
Start of production in 1989.
Minor changes in 1991.
And final "facelift" changes in 1992.

As for wiring diagrams, I can only think of two sources of information.
Haynes (as you mention) and AutoData.

Sadly Vauxhall's Technical Info System (TIS2000) did not include wiring diagrams for vehicles manufactured before 1999.

I will have a look on my AutoData software later to see what it tells me. I will then report back later.

As for semi-conductor information, I can only recommend seeing if RS components or the original component manufacturer have a data sheet in their data bases.

http://www.kynix.com/Detail/40578/U2555B.html

[myfirstcar]

Cheers Robsey,

the last owner said it worked. So the original fuse must have been correct.


All I can think is that the original feed has been severed somehow.

Do you know how the battery feed is split between battery and fuse box. In the Haynes manual is just shows line 30, direct from battery.

[Robsey]

Like I said, I shall have a look at AutoData 3.45 later... and browse my own Haynes manuals.
And then report back.

As for that IC link... it seems to go to a useless web page.
Sorry about that...

[myfirstcar]

The last owner said it worked. Perhaps some corrosion or an age related broken wire?
This car has a Piranha alarm fitted, simple thing with a concealed switch. Don't think it will affect central locking.
Like you I still cant find any good gen on the IC, Kiekert have many patents, maybe this is a custom chip?