Put an ABF into your MK2 and can't get the rev counter working........? here's how...... Pin 12 on Plug G1 in the fusebox is where the dash clocks take the rev counter reading from. On a mk2 loom, pin 12 on plug G1 is red/black and goes straight to the coil. on an ABF loom, pin 12 on Plug G1 is Green/Black and goes to the ECU (pictured bottom left on this plug) cut this green/black wire and join another wire to it (this new wire will go to the ABF coil).... route the new wire through the bulk head and connect it to pin 1 on the ABF coil (pin 1 is located behind the flap under the normal coil plug) .... Start the car up and check the rev counter......
nice writeup! when I do abf conversions I siumply leave the MK2 coil & loom in place, you then chop the plug off the MK3 coilpack and join the red/green wire to the green wire to the TCI-H unit (pin 6) That way you dont have to mess with the dash loom, and you dont have to use the crappy MK3 coil!
Surely snipping that wire at the ECU end and attaching it at pin 1 on the coil would be neater and would work the same? Would save you soldering wires together and would save you looking for a length of wire?
Unfortunately I only thought of it after I'd popped pin G12 out and stuck in a length of wire from a scrap loom and run it up to the coil's negative terminal...
if so, here are pre/post-90 MK2 wiring diagrams for wiring in the MK2 coil & TCI-H unit to a MK3 ECU: pre-90: post-90:
Plus mk3 rev counter signal isn't compatible with mk2 clocks. Can open the mk3 coil and splice to a terminal inside to get a mk2 signal, but imo its a bit of a bodge
Sorry to bring this up again Mk2 abf swap running mk3 coil, do I cut the wire before the ecu or after ecu? Can the wire go straight from fuse box all the way to coil just one long length, or cut after ecu to then have a wire from ecu to coil Thanks
you need to cut/remove the ecu wire to the fusebox, then run the fusebox pin to the coil. if the loom is already in the car and wrapped then you can unwrap a section near the mk3 coil, find the ecu rev counter signal wire, then cut it and run the fusebox end to the coil -ve terminal under the flap
Ah makes sense. So run a wire from the fusebox to the coil. So mines already in the car and wired up, so I just cut the wire after and connect it to the coil that way! So really it's all about just finding the wire and making sure it's in the right plug and just connecting it to the coil haha. Thanks!
exactly, the mk3 has the revo wire to the ecu, which is no good for a mk2 cluster, so you need to cut/replace the wire so it goes to the coil -ve. alternatively you could use one of those revo adaptors the mk4 conversion guys use, MSD 8920 or similar inline with tyhe ecu wire.
I know this is an old thread but my G1 pin 12 is a Green/White wire not Green/Black. Does that mean I have a M3 Fusebox in mine as I think that has a Green/White going to ECU pin 22. In a Mk3 CE2 F9 is a Rev counter signal. If this is the case can I use this to get my rev counter woking?
green/black is usually the vr6 wire colour, for 4 cylinder mostly green/white. the mk2 ce2 fusebox is the same as the mk3 so it just means whoever converted the loom didnt touch the rev counter to g1/12 thats all. F/9 is only used for diesels which take rev counter signal from the W terminal on alternator. Both pins are common inside the fusebox, so you can use either pin but regardless you need to de-pin the green/white in G1/12 before running the MK2 rev counter wire from the mk2 coil or the negative terminal under the flap in the side of the mk3 coil.
Thanks for the explanation. I've traced the green/white to the loom next to the coil, split it and connected to -ve terminal under the flap on the coil.So I have coil negative running to G1/12 now. What I think I'm missing is the 'de-pin the green/white in G1/12' bit. Please excuse me if Im being an idiot but what do you mean by this? I know you've written reams explaining this already but I must be doing something wrong cause I'm having no success. Thanks
if you cut the green/white and put it to the coil negative then you're done, you only de-pin it at g1/12 if you're running your own wire from there to the coil, say if you took the mk2 golf coil wire out and were swapping it over
Well I did this so I have continuity from the back of the clocks to the coil negative and still no joy so I'm guessing something must be broken. I bought set of 16v clocks but didn't realise they're CE1 so when I find some CE! plugs I'll convert it and see if it works.
