SteveW Posted April 14, 2010 Share Posted April 14, 2010 Hi Guys, Right I've been trying to do this mod for the last couple of days and I just can't get it to work. Basically I've followed Alex's excellent guide and got my cable soldered in, I tried it the first night and I couldn't get any sound to play. So tonight I removed the cable checked it works with my home amp which it does just to verify I didn't have a fubbared cable. So soldered back onto HU and checked continuity between channels with a multimeter. Set my multimeter to continuity mode and it shows a large one on the left of the display when no continuity is present and reduces to 0 for a 'perfect' connection. When the unit is in the car with the ignition off or on the table I get good connections between left channel on 3.5mm jack and left channel on tape deck board and no continiuty to other channels, same for earth and right channels. When checking against the correct channels i.e. left to left, ground to ground etc I get continuity readouts of 003/002. However when I turn on the ignition and check across channels I get a continuity readout of 548 left to earth or right to earth. I also get 548 if I check the left or right channels to the HU metal case. The HU case when checked against the earth shows a continuity of 003, Is this correct? I don't think I should be seeing any continuity between the left channel or right channel and the earth and I don't think the case should be an earth should it? Also tonight when I tried it and put the empty tape into the tape deck the unit played forwards for a few seconds then back then ejected the tape and said 'error' on the display. Tomorrow I'm gonna remove the cable and try the headunit on its own I hope it all works OK Whilst the HU has been out I've done the fix for the left channel on the CD player so hope I haven't knakered anything or put it together wrong . .. Hope this all makes sense, I think I've got a short circuit somewhere . . . . Quote Link to comment Share on other sites More sharing options...
pathfinder123 Posted April 15, 2010 Share Posted April 15, 2010 Hi Steve, From your measurements I would say that you have things wired up OK. You are seeing continuity on each cable end to end, and the earth is also connected. Yes, you should have continuity between the grounds on the plugs at the cable ends and the HU. If the tape is being ejected, then I think that is your problem. I believe that you need to have a tape (or a dummy cassette) in the HU to allow the Tape position to pass the audio. I made up a dummy cassette by removing all the tape from it. You need to find and cure the tape "Error" problem. Cheers S. Quote Link to comment Share on other sites More sharing options...
SteveW Posted April 15, 2010 Author Share Posted April 15, 2010 Thanks for your reply mate much appreciated. Right I have solved my issue!!!!! Problem was a few things: 1st and major problem was a small bit of solder ad dripped and was connecting two different parts of the tape deck board so I did have a short circuit but not from the cable was from elsewhere. 2nd and major problem was that the cable I have used is quite thick and when it was wedged between the HU base panel and tape unit it was stopping the tape from turning hence the 'error' message. Everyone be aware of this I just re-routed the cable and sandwiched it somewhere else to stop it getting pulled. 3rd and finally the IPhone is FAR too clever for its own good. Any other MP 3 player (I tried 2) work with the ghetto mod I have done however the iphone somehow knows its connected to the ghetto mod and decides it doesn't want to recognise there is anything plugged into the headphone port!!! So plays the music through its internal speaker. When my IPhone is connected to the hifi downstairs and the amp in my bedroom with the exact same cable that is now in the car it works fine! But not with the Ghetto mod. I have no idea why this is..... Has anyone got an IPhone working with theGhetto mod??? Thanks Steve Quote Link to comment Share on other sites More sharing options...
pathfinder123 Posted April 19, 2010 Share Posted April 19, 2010 Pleased that you have most of it going Steve. Solder in the wrong place will get you every time.... S. Quote Link to comment Share on other sites More sharing options...
shad0wca7 Posted April 21, 2010 Share Posted April 21, 2010 Hi Guys... this is my first post and I'll introduce myself later (thinking seriously about getting a 350).. anyway I was browsing around and noticed this. I think the problem you are having with the iPhone is that it isn't detecting enough impedance on the headphone port so assumes that nothing is connected. Try adding a resistor (~ 32 Ohm) to each channel. ... I havn't done analogue electronics for a while but I think this should work You can probably get the resistors from Maplin for 10p each Quote Link to comment Share on other sites More sharing options...
SteveW Posted April 21, 2010 Author Share Posted April 21, 2010 Hi Guys... this is my first post and I'll introduce myself later (thinking seriously about getting a 350).. anyway I was browsing around and noticed this. I think the problem you are having with the iPhone is that it isn't detecting enough impedance on the headphone port so assumes that nothing is connected. Try adding a resistor (~ 32 Ohm) to each channel. ... I havn't done analogue electronics for a while but I think this should work You can probably get the resistors from Maplin for 10p each Hi mate thanks very much I'll give that a go and see if it works, hope it does work I keep having a play and don't get nowhere. Cheers Quote Link to comment Share on other sites More sharing options...
Pimm Posted April 21, 2010 Share Posted April 21, 2010 Hi Guys... this is my first post and I'll introduce myself later (thinking seriously about getting a 350).. anyway I was browsing around and noticed this. I think the problem you are having with the iPhone is that it isn't detecting enough impedance on the headphone port so assumes that nothing is connected. Try adding a resistor (~ 32 Ohm) to each channel. ... I havn't done analogue electronics for a while but I think this should work You can probably get the resistors from Maplin for 10p each matey Quote Link to comment Share on other sites More sharing options...
elfman Posted April 26, 2010 Share Posted April 26, 2010 I had the same problem with my iphone! was so confused when it wouldnt work but my ipod would, i jsut got over it and used my ipod all the time, still a bugger though! Quote Link to comment Share on other sites More sharing options...
SteveW Posted April 30, 2010 Author Share Posted April 30, 2010 I had the same problem with my iphone! was so confused when it wouldnt work but my ipod would, i jsut got over it and used my ipod all the time, still a bugger though! thankfully its just not me, getting the resistors tomo so will feedback how I get on. Quote Link to comment Share on other sites More sharing options...
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