MattDon wrote:ITS THE WIRE, the only immobiliser is the factory unit and it seems to be working fine, the big question now is how do i disconnect the old wire coming out of the fusebox. its some sort of crimp on connector which id also need to source, can take a pic if it helps.
who would have thought it, guess i should try to find the problem but its a tricky job.
OK, IT'S THE WIRE. I have to disagreee with your desire to bypass the wire with a replacement that you will run some along other path.
If it is a solid (one length, not un-stranded) wire running from the fusebox to the inetia switch, then you have a real dilemma: How can that be? If you have one damaged wire, then you must assume you have several damaged wires so you must find the damage point and fix everything.
I would approach it in a different manner.
First, I would find out how far away from the fusebox and how far away from the inertia switch the problem is. HOW? There are tools, often called TDRs ( I don't know what the acronym means) that cable installers use to test their work. They measure the distance from a point where the signal meets with a gound or end of wire.
Computer network cable installers use them all the time (at least I did when I was a bit younger). See if you can't find someone that has a similar tool. You make up a simple adapter using a RJ11,12 or 45 plug with a short wire coming out and connect it to the suspect wire at each end - one end at a time. Hit the test button and the tester will tell you where the echo stops. If it close, follow the wire's path and investigate. If is a long distance, do the test from the other end. Again, trace the wiring to find the fault.
I have 2 testers laying around here that I use all the time - I last used it to find out where the sheet rock installers nailed through the garage door controller wire when he was building his new house. It was fully covered up and we didn't have a clue what path the electrician followed when he ran the 2 conductor, 18 gauge wire.
The reading from the controller was 27 feet. From the door opener it was 3 feet. We knew where the nearest joist was , so going in the direction toward the controller, we measured around 3 feer and opened a 6 inch hole and found the wire staple was actually the culprit, not the sheet rock installers. A lot less work than tearing the entire ceiling down.
My concern is that the wire you are looking for runs down the center tunnel area. To damage the wire, it would need to be cut or crushed to not deliver the power to the inertia switch. Cut? How? Did you have work done along that area? Crushed? Was something heavy laid on/in the console? Shoved between the seat and the console? Is it being cause by the harness running across a metal mounting instead of around it?
Any of those issues will result in other wires failing sooner than later.
Find AND FIX the cause so you know nothing else is going to jump up and surprise you.
One last thought. Did you remove the controlling fuse and make sure the contacts are nice and clean? How about the inertia switch? Are the connections of the switch and plug nice and clean?
Did you replace the fuse for good measure - even though it "looked fine"? Getting the wrong voltage at the end of an uninterupted wire run means one of several things: Damaged wire with a huge resistance in between or, more commonly, a dirty connection at either end which is reducing the voltage due to the high resistance at the connection. WIth no load, you might read full voltage at the wire at the bad end but once a load is applied, you will see the voltage drop as the connection can't handle the load.
You said you examined an old harness to see the route of the wire. Was it an S2 harness? From what I read, the S2 uses a different imobilizer than the SE and different connections to different wires.
Before jumping to any more conmclusions, I would first test to make absolutely sure the problem isn't in the FUSE/FUSEBOX or at the inertia switch/plug. Then, I would get the proper wiring diagram for the S2 imobilizer and carefully test the fuel cut-off feature. Now, you know it isn't a bad connection at the imobilizer that appears to be doing everything else correctly.
You are dealing with a GM designed harness. They love to make connections in the middle of the harness which often fail. If the imobilizer is capable of turning off the fuel pump, then there are 2 more connections you need to find and test or your bypassing wire might eliminate that feature from the design.
If I was in the UK, I would be more than happy to loan you my cable tester, but I am sure you can find someone over there that installs phone systems or network wiring and they should have one or know where to get one.
Good luck.
