immobiliser?
disable it
what have you changed? look here first

check for power to ign relay fuel pump relay ecu relay.rectify faults
check for power to start terminal on starter.rectify if faulty
dazza

Pulled the dash out to get a better look. Can see a black box with 2 wires from behind the ignition barrel (from the plug) going to it. One of the wires coming out of the box is sitting bare, it must have come out of something, maybe i knocked it accidently. Looks to be the earth, but im not sure. Black box has a patent pending number 640944 and a serial number but thats it. Says australian made. Not sure if this is some kind of ignition module??

The little light does not come from an alarm, it is just a flashing unit i think. There seems to be inline fuses everywhere i have checked as many as i can see. Im running an EMS dual sport, i was thinking that maybe there is something wrong with that, but i doubt it.`

Buy the sound of your dramas you did not originally wire the car which can be a pain when you are trying to diagnose a problem.

Not connecting a earth on the instrument cluster will not stop the car from running as the earth should be specifically for the instrument cluster only. Earth wires should be as short as possible and run direct to the chassis from their source.

You mentioned a red flashing light so I assume the vehicle has a alarm system or imobiliser. Chech the fuse for this. It should be a inline type and may have two. One is for constant power and the other will come from the key in acc or start position. So the security knows when the car is being used and wont arm.

Check the fuses with a multimeter as they may look fine but still be faulty and check you have not bumped any connections under the dash.

If you dont feel confident going completely through the electrics get someone qualified to take a look. The CA elecronics are not that complicated when you examine on a schematic but if the install into the car is a dogs breakfast then it may be a slow process.

Im having a few dramas with my car. 1200 ca18det, wiring is absolutely horrendous under the dash. A mismash of old and new loom, pathetic really! I made up a new dash plate and was installing the speedo/fuel gauge/temp gauge back but forgot to connect the earth wires to the back of the speedo unit. There is no click or crank on turning the key, nothing at all. I have a red light that constantly flashes as an alarm, it is flashing with the key in off, but it goes out when i turn the key to any position (acc etc). Im assuming the light is somehow wired to the ignition. I have checked power at the back of my ignition cylinder (the plug) it has 5 wires and 2 have power in off position (one over 12v the other under 11v). I need to get the damn thing rewired i guess, but would like to get her started before then, as i assume i have burnt out a fuse or something. All fuses seem ok. I accidently crossed two fuses and the fuel pump started working, this usually happens in acc. So im guessing there is some kind of power drain when i turn the key?? Any help appreciated.