# Wiring Technicalities CE1 ABA



## mikes86lego (Apr 30, 2012)

I've been huntin for the past few hours, and maybe searching and drinking should be outlawed, I'm not entirely sure...

But I'm on a2resource, as well as a couple posts on here, trying to make sense of this. Taken from a member on here, so no copying was meant in a negative way.
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Color Gauge Description

Black 12 Coil output stage - 12v switched power 
Yellow/Blue 20 ECM T68/6 - Ground for Fuel Pump Relay(85) 
Red/Yellow 14 ECM T68/54 - Needs 12v power 
Blue/White 20 ECM T68/65 - Speed Input from Instruments (Is this necessary for running an A2 cluster?
Yellow 20 20 ECM T68/21 - Transmit to data link connector 
Grey/White 20 ECM T68/43 - Recieve from data link connector 
White/Yellow 20 ECM T68/28 - Ground terminal for O2 Relay(86) 
Red/Blue 20 Splice - to O2 Relay(85) 
Red/White 16 O2 Sensor - O2 Relay(87) 
Red/Yellow 16 Fuel Pump Relay 87 - O2 Relay(30) 
Red/Blue 12 ECM Power Supply Relay(87) (none of this really makes sense. Not sure why, but STUMPED)
Black/Brown 20 ECM T68/9 - ECM " "(85 as marked on relay) 
Blue/White 20 Coolant Sensor - Temperature Gauge 
Yellow 20 Oil Pressure F1 - Oil Pressure Warning Buzzer 
Blue/Black 20 Oil Pressure F22 - Oil Pressure Warning Light (I presume I run these to their individual descriptors, and a ground from those to the chassis?)
Brown/White 16 Engine Block GND 
Yellow/Black 20 ECM T68/5 - Check Engine Light 
White/Blue 20 VSS #2(signal) - to speedometer (if A3 cluster installed) 
Green/Black 20 ECM T68/22 - Tach output from ECM, to gauges. (Necessary if using A2 cluster?)
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Now then, from what I have gathered, those are the colors from the ABA harness, and where they need to be attached to a CE1. I'm trying to make this as painless as possible for me, and so hopefully can post it up for others. I'm trying to find what color wire to look for on the CE1 cars and running into some errors. 

The problems I have encountered, are in red italics, with my question in parenthesis.

EDIT:
Red/Blue 20 Splice - to O2 Relay(85) 
Red/Blue 12 ECM Power Supply Relay(87)
I presume that I splice a wire from the ECM relay to the O2 relay? Making it so the O2 is active whent he ECM is?


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## craigerk (Feb 4, 2009)

I finished my aba swap not too long ago and I kept all my pages book marked luckily. These pages were my savior for info, I read them all to make sure I got all the info I could and also made an excel spread sheet with the wires. 

CE1/Us built cluster wiring:
http://www.a2resource.com/electrical/CE1cluster.html

Minimul list of wires needed to run an ABA plus other info:
http://forums.fourtitude.com/showth...inimum-wires-needed-for-a-OBD1-ABA-2.0-to-run

DIY MK1 ABA swap:
http://forums.vwvortex.com/showthre...2.0-swap-2.0-into-A1-2.0-into-MK1-info-thread

Another DIY:
http://forums.vwvortex.com/showthre...into-MK2...-new-clean-thread...-list-of-parts

DIY MK2:
http://forums.vwvortex.com/showthread.php?3299652-DIY-2.0L-ABA-Swap!-New-and-Improved!

But to help answer your questions as best I can...

Blue/White 20 ECM T68/65 - Speed Input from Instruments (Is this necessary for running an A2 cluster? From one of the threads (btw, mine didnt need it, obd1, it runs fine without it):
VSS INFO

there's stories running around that if the vss is not connected the motor will cut fuel above 5k rpm in 4th and 5th gear...or it won't allow you to travel at high speeds on the freeway and that you need to connect it/ground it/run a certain cluster/etc...this seems to occur more randomly in obdII swaps. i personally have not be able to 100% confirm why certain obdII swaps will do it while others will not. however there are simple work arounds to this issue should it arise in your swap be it obdI or obdII. likewise these work arounds will work no matter how you chose to wire up your swap:

thanks to mozcar78 for this obdII solution:

vss TO ecu (connected to VSS wire @ pin 27)--/--(U2/2)------back to ecu through T28/27


thanks to B4S for this obdI solution:

OBD1 connector, the tach out pin is #22 (green/black), and the VSS pin is #65 (white/yellow). Connect them together and voila, a 12v pulse signal to fool the VSS


and lastly you can replace the chip with a TT performance chip and this will also solve the issue. however like i said you won't know if you have a problem until after you get your swap running. 

Red/Blue 20 Splice - to O2 Relay(85) 
Red/White 16 O2 Sensor - O2 Relay(87) 
Red/Yellow 16 Fuel Pump Relay 87 - O2 Relay(30) 
Red/Blue 12 ECM Power Supply Relay(87) (none of this really makes sense. Not sure why, but STUMPED) I beleive this should all ready be wired into a relay in the aba harness, atleast mine was, it's to preheat the o2 sensor until its up to temp

Yellow 20 Oil Pressure F1 - Oil Pressure Warning Buzzer 
Blue/Black 20 Oil Pressure F22 - Oil Pressure Warning Light (I presume I run these to their individual descriptors, and a ground from those to the chassis?) you only hook up the oil pressure warning light to your warning light, not the buzzer

Green/Black 20 ECM T68/22 - Tach output from ECM, to gauges. (Necessary if using A2 cluster?) you have to connect a tach wire from your coil to your tach in the dash, that wire doesn't work, this is in one of the threads I posted above though:

Ignition Coil
6) MK3 coil will require a ground wire to be run from the ground terminal to the tachometer wiring inside of the vehicle for MK2 gauge cluster.

a)The ground terminal is the bottom post under the cap 
(plugs facing passengers side)

You just pop off the cover and press a small connector onto the negative terminal. You have to spread it out a bit because 
the lug on the coil is kinda thick.

That didn't work for me for some reason, so I ended up just tapping onto one of the 3 wires coming off the coil plug, its either red/black or black/red


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## mikes86lego (Apr 30, 2012)

Thanks for the clarification good sir! I was wanting to do a diagram per the one that's around for megasquirt. How did the spreadsheet come along? cause that was my next thing on the list. 

once again, thanks man!:beer::thumbup:


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## craigerk (Feb 4, 2009)

It worked pretty well cause at least I had all the wire colors in one place. I'm actually going to make another page in it for wire to wire. So it would have something like; 

"aba harness wire color/ what it does ----- ce1 harness/cluster/ground/positive wire color, where it is" 

So if I do another swap I don't have to go back and forth between excel pages. I Aldo made a sheet on every part I could think of that would be needed for the swap so I had it all before hand. (Luckily I had a whole donor car, but it was obd2 so I had to get some obd1 parts)


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## craigerk (Feb 4, 2009)

Also, if you want shoot me a pm and I can get you my excel sheets if it helps. They're not perfect but helped me a lot.


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## Brad99 (Jun 29, 2011)

Awesome thread guys!! I'm so happy I found this thread. I'm doing this same swap into my 1987 GTI. The only catch is I only have a week to do it because this is my daily. I got the engine and accessories last weekend but no wiring harness or ecu :banghead:. So my question is should I go buy an obdII wiring harness and ecu or should I make my car ce2? I know the engine is obdII and I have a neuspeed cam and chip for it along with exhaust manifold. I need engine and trans mounts also. But I'm going to go get some kind of wiring harness this weekend from the junk yard I just need to know what to get. any and all help is appreciated.


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## InlinePerformance (Oct 25, 2008)

*Harness's*

I can build self contained easy to install aba harness's -you meed a battery hook up, and ignition switch power(old coil power works great) the lead to your fuel pump and well an aba and it will run. All relays are built in to my harness so its very easy. If anyone is interested or wants more details hit me up with an im or on ig @tdc_shop built many and so far everyone has been happy-done many aba swaps and every swap has started first try....im an aba guy


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