keyless by Hornet doesn't unlock

[nariusb]

Dear Narius,

Sorry to miss your quest for help in the forum. I've attached a copy of
the
pdf for 1989 on Central locking so you can check my suggestion.

Power to the key switch in the driver's door comes from Fuse F30 trough
a
Red/Green wire. It is the source you should use to power the inputs in
the GM.

To unlock, this Red/Green wire is connected to the Blue/Brown/Yellow
wire
coming from the key switch (it is Blue/Brown inside the door).

To double lock, the key travel first connect the Red/Green wire to the
White/Red/Yellow wire, and finally, ALSO connects to the Red/Green wire
the
Blue/Brown/Yellow wire.

As you are using relays to interface, you should energize the coils
from a
fused 12Vdc at your election, preferably, the same source feeding the
Keyless module. The dry contacts of the relays, should do the bridge
(connection) from the said Red/Green wire to the intended operation
circuit, so for example:

For the unlock operation, your relay pin 30 should go to Red/Green,
relay
pin 86 should go to your 12 Vdc source, relay pin 85 should go to the
grounding contact of your keyless module, and relay pin 87 should go to
Blue/Brown/Yellow wire.

For the simple lock operation, your relay pin 30 should go to
Red/Green,
relay pin 86 should go to your 12 Vdc source, relay pin 85 should go to
the
grounding contact of your keyless module, and relay pin 87 should go to
White/Red/Yellow wire.

For the double lock (Central arrest) I would say that you should first
apply a lock, wile doing so you should apply the unlock. Not sure how
will
the system behaves if you first apply the unlock or last remove the
unlock,
but as in any case you will have to use a third relay to prevent mixing
signals, I would do the following:

For the double lock, relay1 pin 30 should go to Red/Green, relay1 pin
86
should go to your 12 Vdc source, relay1 pin 85 should go to the
grounding
contact of your keyless module, and relay1 pin 87 should go to
White/Red/Yellow wire, AND relay2 pin 30, AND relay2 pin 86, relay2 pin
85
should also go to the grounding contact of your keyless module, and
finally, relay2 pin 87 should go to Blue/Brown/Yellow wire. This way,
the
grounding contact will first energize the lock, and will de-energize
both
simultaneously. That's the best we could do without sophisticated
timing
relays. Of course, if you got your double lock already working (which
means
the sequence is not important) or simply accept the normal lock only,
this
last paragraph can be ignored.

Good lock and do ot hesitate to write me if nay doubt.

Javier



> Thanks for your indept reply. I read it very carefully and reconected according your instruction with the same end
> result, even with double locking connection, where all three 30, 85, 86 pins went to module ground. The same result
> locking no unlocking.
> SO I also tested the relay ping where module connects and the one that should unlock doesn't go to ground - it always at
> 12V. The locking one drops to 0 when locking and back to 12v at rest.
>
> So I guess this proves the fauly module. I could try and look for another like this on the web ( I bought mine on ebay)
> or maybee repair but not sure with transistors to replace, because there's no burn marks. Any ideas Javier?
> And again I'm gratefull for your time.
> Cheers
> Narius
>

OK Narius,

first, check the system is OK by grounding manually the relay pin corresponding to unlock, confirm unlocking is applied correctly to the car system.

Then, I would verify the module specifications on the outputs. Are you sure there are two dry contacts intended to close to ground when the corresponding operation request is issued? May be one of them rise to 12 Vdc?. Do you have a drawing of the module internals? at least, related to the outputs?

Any debug should start from identifying the pin destined to unlocking, the one you are using to operate the relay, and follow in the conductive pads, it should lead you straight to the driving component for that output, either a micro relay or a transistor.

Javier

OK Narius,

I would start from the principle that similar outputs should use the same circuitry. I mean, the Locking output should have the same components than the unlocking output.

The component you surrounded with a pink circle seems to be out of place, if you look at the printed circuit component mask, there is a white rectangle aligned with the rest three Marked 100 components (R29, R30, and R31), that I guess, are limiting resistors.

If you asked me, what I see in the pink circle is one half of a rectangular component (as the ones marked 100) and the other half is out of the circle in the other extreme of the white rectangle. If my perception is OK, the output is opened as the connecting component is broken. Please consider I can not see in detail from this picture.

We are talking of component R28, that should be identical to R29, R30 and R31. (I would say they are 10 ohm resistors, you can verify with an ohm meter).

You can test what is going on reading the voltage at the copper hole slightly down to the left of R28. As this point should go to ground when Unlocking.

Please let me know you findings.

Javier

labusas wrote:

> Javier, Sir, I've got to report a success! :-) :-) :-)
> Your observation from a bad pic was just amazing and spot on. I ran to the store got a SMD resistor 68R and smaller in size (that is all they had and this thing was barely visible), soldered it in and the unlocking came alive. So now I've got fully functional system and thanks to you Sir my ordeal is now over. Thanks again!

Narius

I'm very happy to hear that. Though you may want to measure the actual value of the resistors (I believe they are 10 ohms) and replace it whenever you get one (It does not have to be SMD).

68 ohms may be high and leave a very low voltage for the relay coil, making the system tricky when the car battery is low.

Javier

[genphreak]

That's the best we could do without sophisticated
timing relays. Of course, if you got your double lock already working (which
means the sequence is not important) or simply accept the normal lock only,
this last paragraph can be ignored.

So did you get double-locking working too? Any such discoveries with how it is best influenced? Nick

[nariusb]

So did you get double-locking working too? Any such discoveries with how it is best influenced? Nick

Yes Javier's double locking worked but I chose to stick with just normal locking so I haven't testeted it fully to say if there's any consequences.