tma

Got a similar issue here. The two options I\'ve figured are: * Attempt to clean up the audio on the way to the amp via a group-loop isolator. This is a bit of a cludge job, will work somewhat and may reduce a bit of audio quality - but it\'s braindead simple to throw in. * Clean the 12VDC+ line coming to the head unit (tablet in my case) via a car noise filter. You can buy them or build your own.

Totally, that\'s what I presume too. Higher-pitched noise that occurs that starts while on / pre-ignition. That\'s what led me to believe the aftermarket TV installation "birds nest" was the culprit, rather than potentially the alternator (am I wrong about this?). Noise does increase with revs however, so I might be chasing two sources for all I know. I\'ll go the ground loop isolator if I need to. I\'d prefer to do this cleanly and properly and possibly negate the bit of sound quality loss through using an isolator. While I was doing a bit of reading on this before I started attacking the car, some people have pointing out that ferrite cores (usually come with TVs and the like) have sometimes been shown to reduce noise to a similar level of a ground-loop isolator. Could be BS, but they presumably exist for a reason.. Edit: Bleh.. it ended up being the secondary cig lighter socket I wired up. Serves me right for using something that was pretty poor quality. This project has made me feel like an idiot every step of the way. At least I\'ve learnt a lot..

My saga of installing a tablet in the 250T continues. After finding out that my original clean wiring was almost perfect _after_ feverishly splicing cables to track down noise coming through the ground, I started removing all the old cabling from the aftermarket TV set. 5 hours later, I have a truly ridiculous mass of wires which have come out which were threaded all over the damn car. It was a damn joke. Noise is/was coming through the USB charging cable and through the audio output of the tablet - even when using the stock cigarette lighter socket rather than my wired-up secondary.. Putting all shrouds, trim and carpet back this lunch and wrapping the USB charging cable through a ferrite core. Hopefully the noise won\'t be there, or else I guess I\'m going over the ground wires in the engine bay which probably need to be done anyway. So tempting to do a hack-job with a ground loop isolator, but I want to do it cleanly...

It might be worth trying to find another phone with a broken screen (should be pretty cheap). It should still charge the battery, so just hook it up and keep the backplate off for you to drop a battery in to charge. Try and find out which phones use the same battery to increase the odds of finding one.

I have so many dumb questions, so I\'ll post just a few... 1) If an ignition lead has a mismatched resistance to the rest of them (fairly significantly, but well within spec) would this have any impact within an NA engine? 2) Anti-seize on spark plug threads? I\'ve read both yay and nay... 3) ECU mapping is regarded as something you don\'t fiddle with yourself if you don\'t know what you\'re doing. I completely understand why. How do you start learning and what prerequisite knowledge should you have? Thank you kindly