C488ADO 0 Posted February 20, 2011 HELLO tryingto convert to obd2 and kinda hit a block, seen the posts on here but there is no real guide on how to do this , it says cut looms etc but what am i cutting out exactly??? whic loom do i use? the golf loom? or the corrado loom? which one do i add the bits to or cut bits off? and most importantly which bits do i cut off!! lol sorry this is vauge but i really need to get this finished as i need to move the car.... any help appreciated cheers Quote Share this post Link to post Share on other sites
Rams 0 Posted February 21, 2011 Im not the best person to reply but from what I understand is you can cut the excess loom out or leave it in? Depends how neat you want the loom. The loom that you use would be the golf loom that plugs directly into fuse board. From that hopefully you can read what the next stages are or pm one of the guys that have completed the task. Quote Share this post Link to post Share on other sites
C488ADO 0 Posted February 21, 2011 thanks rams, the golf loom seems to have two of those massive round multipin connectors on it do i need to use the fuel rail injectors and wiring from that also? or can i use my original fuel rail injectors and wiring and leave the big multi pin round block connected to the meal housing and just plug the golf one into it?? Quote Share this post Link to post Share on other sites
Rams 0 Posted February 21, 2011 I think you need to use the new fuel rail but perhaps change the pressure regulator as the golf's run at 3 bar and the corrado at 4 bar? I really am not 100 percent sure but I found that the inforamtion wasnt fast coming and was told to refer to how it was done on previous threads when I started asking questions. I would wait till someone of better knowledge has confirmed though. I hope once you master it that you can do a write up as I will be doing mine at some point. I never really got to the bottom of what was required for late rados when doing the conversion. Perhaps the fuel rail will be ok to use? I hope someone gets back to you. Come on OBD2 people, help the man out at time of need! Quote Share this post Link to post Share on other sites
mikkijayne 0 Posted February 21, 2011 If you are using a mk3 loom then you need to strip the lighting and ancillaries out of it, as the Corrado has a separate harness for those. Thats what one of the big multiplugs is for. You really need the mk3 loom and Corrado engine loom next to each other so you can see what to leave in the mk3 loom as you strip it. Thats what I did when I put a TDI in mine. The mk3 loom will be about 2 feet too long iirc, but you can wrap that up and tuck it on top of the fusebox, or wrap it round the strut tower with (I think) the lighting loom. I'm sure there is a good write up on this conversion on Vortex. I'll have a look for it later if I get a chance :) Quote Share this post Link to post Share on other sites
Kevin Bacon 5 Posted February 21, 2011 Yep, the OBD2 ECU harness needs 'bunching up' a bit to shorten it! The Golf loom is also too short in places as well, so some soldering and heat shrinking will be needed. The ECU harness bulkhead grommet is also completely different and won't fit the Corrado's hole, so I used the Corrado grommet, carefully snipped in half and glued back together again over the OBD2 wires. Or if you have a pin extractor tool, you could remove the ECU plug pins and feed them through the grommet properly, but it's time consuming and open to mistakes. The MK3 loom just plugs into the back of the fuse box. The main connectors are all the one way type, so you can't go wrong. Unclip the Corrado harnesses, plug the MK3 ones back in. The little single pin plugs at the top of the fuse box need more attention though, so don't wade in with your size 12s, try and plan it out a bit in advance and don't hack the old loom out - just in case! Quote Share this post Link to post Share on other sites
Purple Tom 0 Posted February 21, 2011 You'll also need to take a 12V live feed (IIRC) from the OBD2 loom somewhere near the fan control module in order to get your fans working properly as the Golf has a different way of operating the fans. I can't remember the colour of the wiring but it'll be in the Bentley manual. I used the Corrado fuel rail and injectors with the OBD2 engine harness. Everything in that respect is plug and play as obviously the OBD2 harness has the correct plug for the throttle body. Hope that helps, good luck! Tom Quote Share this post Link to post Share on other sites
swiftkid 1 Posted February 21, 2011 So is the conversion basically just replacing the obd1 wires with obd2? not sure why but for some reason i just assumed it would involve cutting and splicing into the obd1 wires? Quote Share this post Link to post Share on other sites
C488ADO 0 Posted February 21, 2011 hello guys thanks for te replys! il try and translate this when i get to the car tomorrow? or wednesday... yes it seem slike just a case of splicing the looms together but as i am a dick i just dont know which wires to get rid of... there are som many and what with the golf loom using slightly diffeent colours for bits and pieces plus i have no diagrams for the golf loom which makes it harder i guess.... has anyone got a diagram for the golf loom by any chance? Quote Share this post Link to post Share on other sites
swiftkid 1 Posted February 22, 2011 Hey, hoping to get cracking with this conversion soon myself so are you saying you need to splice the obd1 and 2 looms together or just get rid of headlight wiring on obd2 and plug it all in? Ideally I want everything ready to just swap so its a case of do i buy another loom or not. Quote Share this post Link to post Share on other sites
Rams 0 Posted February 25, 2011 how are you getting on? I picked up a complete obd2 loom today and keen to get mine in. Are there any advantages of running with the obd2 fuse board when converting? Quote Share this post Link to post Share on other sites
C488ADO 0 Posted February 25, 2011 Right hello bud Got it running on the key.... Bit rough bit lumpy??? Not sure why yet need to wire in the Obd port tommorrow need to find out what wire from the golf loom it is to connect yl tk the existing wires in the car..... I installed the obd2 engine wiring loom this was easy as you literally unplug the obd1 loom and replace with obd2 Thus gives you the right plugs for the throttle body etc Then I've cut out a load of wires from the golf loom Il write up some more in better detail probably tomorrow night bus if you get that far then your doing good! Quote Share this post Link to post Share on other sites
C488ADO 0 Posted February 25, 2011 Just started a how to in the wiki section started a write up and submitted got to wait for approval before I can carry on with it , I didn't want to loose te info I had started so I submitted early I can edit it as I go along Keep an eye out for it bud Quote Share this post Link to post Share on other sites
Kevin Bacon 5 Posted February 25, 2011 Got it running on the key.... Bit rough bit lumpy??? Not sure why yet need to wire in the Obd port tommorrow need to find out what wire from the golf loom it is to connect yl tk the existing wires in the car..... Did you hear the throttle body doing it's calibration check on Ignition 2? You should hear a high pitched whine and some clunks from the motor. Once you've got your K line hooked up, you can get in there with the VAG-COM and see what's going on. Clipped to the back of the centre console is a brown connector block with a couple of single pin connectors in it. One for the ABS ECU and one for the Engine ECU. You need to take the Engine ECU one, follow it back to the fuse board and then join it to the K line wire of the OBD2 harness. These wires are thin grey ones, or grey / white. Quote Share this post Link to post Share on other sites
C488ADO 0 Posted February 25, 2011 excellent cheers kev! il get right on it! Quote Share this post Link to post Share on other sites
VRTrickster 0 Posted February 26, 2011 As people have rightly said really. It's been quite a while now since I carried this out, so I'm not exactly sure what it was. I had to do something with the aux water pump wiring. I took a piece from the rado loom. You can obviously use some other wire if you come across this, so you don't wreck a perfectly good loom. Sorry for being vague. You may not come across this. Maybe there was something missing on the golf loom, who knows, eh. Good luck with it all. You'll really notice the difference! Quote Share this post Link to post Share on other sites
