Partyvan 
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Registered: 21st Feb 09
 Location: Nottinghamshire 
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Hi 
 
First off I realise the wiring is different on the 12v Corsa. Basically I've bolted the C20LET in yesterday and now want to tackle the wiring. 
 
Can I pull the old 12v loom back into the car, then just colour match the wires to the C20LET engine loom as per the other Corsa B's? I read somewhere there is more to it than that, ie the fuel pump relay is elsewhere?   
 
All advice appreciated. Best advice will be u2u'd some amazing porn  
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lee mitchell 
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Registered: 26th Jan 01
 Location: kent...drive's: eveyones conversion cars hard lol 
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fuel relay is behind the glovebox.its pin 8 or 9 i think on the relay for the thick red blue wire. u need to join the green rev counter wire from the let to the green wire on the eps if it has it. i run the coolant blue wire, the eml blue brown wire,the thin blue red straight up to the wiring behind the clocks. the brown yellow i leave by the footwell so if ur eml light comes on u can just earth that wire to flash the codes out. leave brown white dsconnected. ignition live werever is easiest to get too. 
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edd1.0 
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Registered: 17th Sep 08
 Location: kettering 
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have you still got the 1.0 ? if so can i buy ure egr valve ?
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Partyvan 
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Registered: 21st Feb 09
 Location: Nottinghamshire 
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quote: Originally posted by edd1.0 
have you still got the 1.0 ? if so can i buy ure egr valve ? 
   
 
No sorry I bought the car as a rolling shell
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pow 
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Registered: 11th Sep 06
 Location: Hazlemere, Buckinghamshire 
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Lee - sorry, explain that again? 
 
So you have the square 9 pin connector on the XE/LET loom, and you connect those pins to what?
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lee mitchell 
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Registered: 26th Jan 01
 Location: kent...drive's: eveyones conversion cars hard lol 
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green to eps in footwell.  black to ignition live, thick red/blue to relay pin 8 or 9 behind glovebox, brown/blue to wiring behind clocks along with the blue and the thin blue/red. brown white not used. brown yellow just left somewhere u can get too easy to earth it to flash codes up. red to permanant live
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john_c20xe 
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Registered: 10th Feb 08
 Location: Eastbourne, EastSussex 
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ecu is on the engine on the 1.0 12v, you will need to get a sport 16v of gsi 16v dash loom, this will come as a whole to wire in the engine, this will levae you the plugs you need in the drivers footwell, then simply get a wiring adapter from twag for a let into gsi and job done  
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Partyvan 
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Registered: 21st Feb 09
 Location: Nottinghamshire 
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Cheers Lee 
 
quote: Originally posted by john_c20xe 
ecu is on the engine on the 1.0 12v, you will need to get a sport 16v of gsi 16v dash loom, this will come as a whole to wire in the engine, this will levae you the plugs you need in the drivers footwell, then simply get a wiring adapter from twag for a let into gsi and job done   
   
 
Is it really worth taking the dash out for that?  
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john_c20xe 
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Registered: 10th Feb 08
 Location: Eastbourne, EastSussex 
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dont need to remove the dash mate, just an easier option imo
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Partyvan 
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quote: Originally posted by john_c20xe 
dont need to remove the dash mate, just an easier option imo 
   
 
So the loom I need to replace is the one that runs from the passenger footwell to the driver footwell and has all the stuff on it for heaters, stereo, indicators, speedo etc...? 
 
And thats easier than just pulling the 12v engine bay loom back into the car and matching it up to the LET loom? 
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lee mitchell 
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Registered: 26th Jan 01
 Location: kent...drive's: eveyones conversion cars hard lol 
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do the way ive said as is easier. plus the 16v loom wouldnt have eps wiring etc
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Partyvan 
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I think I'm gonna go with what you said Lee   Simply because it sounds quicker and I hate wiring  
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scottyp1989 
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Registered: 29th Jul 07
 Location: Warley, West Midlands 
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what is the brown/white wire for?? just out of intrest
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Partyvan 
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quote: Originally posted by scottyp1989 
what is the brown/white wire for?? just out of intrest 
   
 
Probably something un-used like the auto-box, air-con or something.
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Partyvan 
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Hang on a sec guys, on Vauxsport it says RED/WHITE is the autobox wire (unused in conversion) and BLACK/GREEN is aircon (also unused) 
 
http://www.vauxhall-sport-forum.com/phpBB2/20xe-c20let-conversion-guide-into-a-vauxhall-corsa-t106.html 
 
[Edited on 27-06-2009 by Partyvan]
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lee mitchell 
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Registered: 26th Jan 01
 Location: kent...drive's: eveyones conversion cars hard lol 
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brown white is for diagnostics i think but u dont need it. can still flash codes etc and managment light will work
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craig_s 
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Registered: 5th Mar 06
 Location: Birmingham         Drives: mk4 astra gsi 
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ive just done a 1.0 12v to red top conversion,connected all the wires as you have said lee,everrything is working fine apart from no ecu light,got voltage coming down the brown/yellow from the red top loom but nothing from the brown and blue any ideas? 
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Partyvan 
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 Location: Nottinghamshire 
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quote: Originally posted by craig_s 
ive just done a 1.0 12v to red top conversion,connected all the wires as you have said lee,everrything is working fine apart from no ecu light,got voltage coming down the brown/yellow from the red top loom but nothing from the brown and blue any ideas? 
 
   
 
When you say brown/yellow is that the thick wire in the engine bay to the battery positive?
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lee mitchell 
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Registered: 26th Jan 01
 Location: kent...drive's: eveyones conversion cars hard lol 
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fuel relay ok? because if it isnt the ecu light wont come on
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Partyvan 
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 Location: Nottinghamshire 
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Lee you're some sort of wiring god   
 
I'll be sticking up pics of mine tomorrow and would appreciate any more advice when the time comes!
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craig_s 
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Registered: 5th Mar 06
 Location: Birmingham         Drives: mk4 astra gsi 
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well the car runs,however i thought it might be the fuel pump rlelay as i traced the brown and blue to the relay,the relay its self is corroded so ive ordered a new one.ive tested the wire from the relay end to the other end and got no reading.do you know if thats right or do i have a possible broken wire in the loom?
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Partyvan 
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 Location: Nottinghamshire 
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quote: Originally posted by craig_s 
well the car runs,however i thought it might be the fuel pump rlelay as i traced the brown and blue to the relay,the relay its self is corroded so ive ordered a new one.ive tested the wire from the relay end to the other end and got no reading.do you know if thats right or do i have a possible broken wire in the loom? 
   
 
If the car is running then obviously the fuel pump is working, so I'd say your wiring is right   
 
Lee said pin 8 or 9 on the relay... can you confirm which?
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Partyvan 
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Ok so I've got the LET loom in the drivers footwell, and I'm running the wires up to behind the clocks (temp, rev counter, ecu light etc...), now when I cut the existing wire behind the clocks, am I then just joining the wires from the LET loom to the clocks themselves, OR do I tie all three bits together (so each wire is like a Y joint)
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lee mitchell 
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Registered: 26th Jan 01
 Location: kent...drive's: eveyones conversion cars hard lol 
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i always do them as a y
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Partyvan 
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Okay it looks like I'm getting there! 
 
In the engine bay I'm working on the three-wire plug from the Corsa starter/charger loom. There's a red/black (ign live?) and a blue/grey which I've joined to the 1.0 12v engine loom thats still in the bay. 
 
Only thing I think I've got left to do now is the ignition live on the C20LET loom in the engine bay (single pin plug under the dizzy, black wire). Where do people join this to?
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