u cut ur ISO plugs off from the car side? thus leavin you with open ended wires? Oh dear...i certainly wouldnt have done that. it causes a faff when puttin other radios in or performing tests like u want to now. If its because the radio you have came with a loom with open ended wires not compatible wih str8 plug in, you should have repaired that with a female block to do so rather than cutting off the oem wiring loom off the car.
The aerial booster cable you have purchased is very much on the shelf at halfords...theyr usually £14.99 from their..(confession.......i work there...lol)
You will probably find that the original radio's signal will be better anyway. The booster is only otherwise recommended when aftermarket radios are installed because the signal level with aftermarket radios arent strong enuf with the VW's and Audi's n nethin else within the group of motors. Many have been ok without em of course...however, yours is one of the ones that otherwise requires a means of signal boosting.
now IF you managed to temporarily test ANOTHER aftermarket radio besides your current one in their against radio signal and find it is ok with that one....then it will be that the TUNER built into your new radio that your intending to install is knackered or faulty or generally poor craftsmenship.
