Well I found mine relatively easy but the documentation was a lot more detailed. Ha.
Only issues I had with mine is I'm guessing due to age a wire snapped/pulled out of a factory crimp connector... spent a while trying to figure out why my indicators were stuffed and after triple checking my work I spotted it. Then I got one wire mixed up with another later on but that was easy enough to sort.
Anyway, I'll try and sort a few out for you but don't have time to answer them all, but heres a start.
-To start with, the relay on the schematic doesn't seem to make sense in theory. The numbers and what they do don't seem to work.
Well let's just ignore the numbers, as they may vary by manufacturer, type of relay etc. Plus I don't know them off the top of my head.
Basically what will be happening is if you know how relays work, the acc goes to one side of the relay coil, now the alarm sinks the other side if it has been disarmed so essentially, if the key is in the acc or ign position there will be +12v on one side of the relay coil, then if the alarm is armed it will be also +12v so no potential across coil, relay doesn't operate. Alarm is disarmed and so goes low (0v) now there is potential across the relay so relay closes and completes the circuit allowing ignition or starting or whatever circuit you'd killed. Now relay coils technically don't have polarity so doesn't matter which side is positive or negative, except some may have diodes or leds, so it will matter with those relays. Circuit you're killing should have the relay contacts wired in series, on the NO terminal I belive so that if someone starts disconnect the alarm or it's power the default state of the relay causes that circuit to be open.
Anyway there is the possibility though using this method that if the acc is off and the alarm is driving it high then the relay will close, however then in theory there is nothing completing the circuit as the switch for the ignition/starter is open. Unless the alarm detects the acc wire state and changes state accordingly... hard to say. Otherwise I could be wrong. But it may be causing dramas trying to kill other circuits that aren't reliant on the ign or starter positions on the key switch if my theory is true.
Although that just doesn't seem right... surely it would be better to have one side of the coil to constant +12v and the alarm trigger for the relay floating unless disarmed and then it will go low 0v, closing the contacts.
Dunno, may be a typo or incorrect diagram... best bet is to have the alarm running more or less and with a meter check what that relay output is doing in the armed and disarmed states. Unless someone can shed some light on it.
Dodgy as having the relay externally though anyway. If it's an easy to find location its as simple as tracing it back to the alarm and you could then make it useless pretty easily, easiest way would be to just disconnect off the contacts and short together, but you could also trigger the coil.
edit: Maybe the alarm leaves it floating... oh I dunno, I'm tired and my brain hurts from too much thinking.
-As its a diesel, without a coil, the wires that go to pin 86 and 30, we've cut into the Auto Inhibitor. What is alternative wire to use in a diesel, obviously there is no coil... Its the 'immobiliser' function of the alarm, so needs to stop the truck from starting.
No idea honestly how auto inhibitors work, as I've started to think though, if it is relying on the ign or start position on the switch to being open to completely kill it then this may be the source of problems... you can kill the starter, I did ignition and starter in the sierra. If your diesel isn't all mechanical may be able to kill some electronic element of the fuel system... like a fuel stop actuator or similar ?
- The white wire at the bottom says ACC, but doesn't have a power symbol like everything else, which makes us assume that that wire is left for added accessories like bonnet pins etc??
Most likely a connection to acc, but your other theory also has merit, I'd honestly just get everything else sorted and try it with and without.
- The blue wire above that says -ve and door, so that would by design mean that it simply needs an earth connected to it...?! And that can't work. We did make it do what we thought was the right thing, but I'll take suggestions on the matter..!
From memory door switches have one wire going to them, then by their design when you open a door the pin moves out contacts close and the switch body is connected to the chassis so the wire is pulled down to earth. If I'm making sense, so that input would be -ve / earth triggered to detect a door/boot/whatever open. All door and boot pin switches should be commonend together so it will detect any of them, although IIRC you need to watch for any interior lights that may be connected to them, some cars may be triggered differently and may need diodes etc. I cannot say as It's not something I've had a huge amount of experience with.
- And finally, the locks aren't tripping when the unit fires, but we think we've just tapped the wrong wire somewhere, so we should be able to sort that one out.
That and I'd double check the right wires and going to the right spots.
- The orange wire down bottom with the foot brake circuit, we've assumed that by not connecting it to anything, it should negate that function of the alarm. Or does it need to be connected according to the schematic??
Well what is it for I'm not actually seeing why the alarm needs anything to do with the brakes pedal ?
-Confusingly, its cracking 20amp fuses in the power outlet box, but then the 15amp on the red power in line is surviving, as are the rest of the 15amp fuses in the system. Seems very strange to pop one out of two fuses on the same line, and to pop the higher rated one...!?
So where is this fuse on the schematic ? If the 15 and 20A are both in series on the same wire, could be a short to earth/chassis located between the two... just thinking that if there is a short on the cable between the two fuses and ground. Path of least resistance and then essentially the alarm and 15A fuse will be in parallel to the short circiut, so should be okay and so doesn't blow, but the 20A is part of the circuit that is pulling huge amounts of current due to a short and so promptly blows.
I think, but I'm tired and I may be wrong. So am ready to be corrected.
Alarms suck - no wonder insurance companies reward owners to have them, they deserve it!
PS. I never said I was any good at this, just having a crack, so be nice
Maybe get a better one next time though with a bit more info and it really should be all black wiring... but it can make it a lot harder to wire.
Oh and I'm an alarm installer but not for cars, so some of it may be a bit off.
