[kermit1302]

Hi,

I have a weird problem with my car. When driving the immobilizer warning light comes on when driving. It doesn't come on properly, more fades in gradually and is very dim. To make it weirder it will disappear when I turn the a/c on. The car starts and runs fine.

Any ideas??

Thanks

[The Gonz]

When unrelated lighting plays up like that, it's most commonly due to poor earthing, forcing residual current flow through another lighting path which presents as lower resistance than the intended earth. This is easily seen in some older cars when their tail or headlights blink in unison with their turn indicators.

I would be checking the integrity of connections behind your instrument cluster.