Immobiliser Issues

[R11ysf]

My Mk1 Golf has just come back from the garage and its dyno run and the immobiliser has stopped working.

It was a very basic 90's one which required a long cylindrical key to be pushed into a hole for it to start. Before this was done there was a small flashing red LED and without the key turning it off it would not let anything electrical work - wipers, indicators, etc were all stopped. So i can presume this is between the ignition and the main fuse box.

My Golf has been converted to a 1.8t and so now has a second ECU and wiring loom but all this was spliced in without a problem. The car got VERY hot on the dyno but apparently it was still working when it came off.

Now the immobiliser has not got power so the LED does not flash and it does not stop the fuse box getting power. Rather than the immobiliser stopping the car from starting (which I presumed it would do if it lost power) it now allows the car to start freely as if the immobiliser was not even there.

As an aside, which may not be related, the brake lights also lost its permanent live at the same time.

Any suggestions please folks?

[R11ysf]

Bump for the daytime crowd please

[The Jolly Todger]

Dodgy earth strap somewhere?

Have you checked all fuses?

Also what did you get on the dyno?

[R11ysf]

Earth strap replaced, all fuses checked.

and 1.8t AGU with megasquirt was 186bhp and 240ft/lbs but 'my man' said it is being severely restricted by the Mk1 standard exhaust at 1.5" whereas the downpipe is 2.5" so I need to cut the mid pipe box out or put a bigger mid system in place.