Howdy! Just a quick question! My jaguar xj8 at the time of purchase had an aftermarket stereo in it! The owner requested it not be sold with the car so I respectfully accepted and reinstalled the factory radio! The factory stereo harness had been sliced and hard wired! I re connected the wires and carried on my way! I've recently decided to install a stereo my self and decided to hardware it into the factory plug, as it had been previously! Sounds great accept when I step on the gas pedal it shuts off! Once I come to a stop, it turns back on! Wtf did I do lol

 

Sounds like a dodgy connection somewhere, either a wire is disconnecting, or something is moving and creating a short. Only real solution is to pull it all out and check everything, sorry

 

Don't be sorry! Any help is always appreciated! I just find it very weird once I touch the gas pedal it goes off! And Won't turn on till completely stopped! Will stay on at coast or very light gas then about 10km bam! She's off again! Could I hve missed a wire or should I have connected both yellow and red together from the stereo to my ign power wire on the harness!?

 

So I found that the source of the problem as a wire that couldn't hold the voltage on accelerating! Does anyone know what wire is the ignition wire and is there a good one for constant power? Can't find this info anywhere! Thank you

 

Sounds like you might have found the speed signal wire? Can't be certain without a wiring diagram though. Now I know there's one out there somewhere...

Found it!
http://www.gusglikas.com/images/Auto.../jagxj1999.pdf

If you're lucky enough to have wiring the same colour, your constant live is the Brown with Green tracer, and the switched Ignition wire is White with Yellow tracer

A quick check with a multimeter will tell you which one is constant live and which is ignition though

 

Great!! Thanks a tonne!