mk1 golf diesel

yeah basically same deal as wiring up any mk3 engine, if the mk1 is diesel fusebox this thread has you covered:
https://clubgti.com/forums/index.php?threads/249714/

with the ecu relay section its even easier as the mk3 diesel 109 relay only has 3 pins:
30 - live
85 - G1/7
87 - G1/10

if you wanted a standard 4 pin switched type relay instead of the 109 then same as above but loop pin 30 to pin 86

obviously ignore the rev counter part, for mk1/2 diesel rev counter you woudl need to swap the alternator for a n/a or td type mk3 one, then wire it to pin W. alternatively there is info out there on how to add a W terminal to an alternator without one, plus you can even modify mk1/2 diesel clocks to accept the low amp rev counter signal the mk3 tdi ecu puts out.

if you dont have a rev counter then you can leave it off, but note they still use the signal for the oil warning buzzer/light if pressure drops at around 2k+, so this will no longer work

edit: oh and instead of a fuel relay in slot 2 you would pop in the mk3 glow plug relay, and the mk3 glowplug wire Z/1 will fit straight in CE1 fusebox slot N once you trim the locking clip off the side (you'll see what i mean)

 

the original gearbox will fit fine, use a new 210mm cluch kit and you'll need to get a 210mm flywheel to go with it.

the mk3 tdi 02a gearbox is also a good option, though you'll need to get 100mm mk1 shafts, fit the mk3 cable gearstick & cables, then get hydro clutch setup or buy one of the SEAT cable clutch kit to get it all in there

 

dont need much really. for starters grab the 14 pin plug that connects to the main sensor harness and strip out as much length as you can. inside the car pull the clutch and brake switches with plugs and as much loom as you can. grab the accelerator pedal loom as well, dont cut any of the pedal wires just chase it all the way to the blue plug in the scuttle. grab the diagnostics plug and pull that out as well with a decent length of wire.

The MK4 diesel engines have an ecu relay above the relay carrier, this will be wired up thru the accelerator pedal loom. so chase the wire for that back to the relay and pull it all out as best you can, the red and blue wires on the relay are tapped off to the car harness grab a good length of both if you want to use the mk4 relay holder, if you want to use a mk1/2/3 relay holder then you dont really need any of the ecu relay wiring except for stocks of spare wire!

have a read of this:
https://clubgti.com/forums/index.ph...install-faq-now-with-added-dieselness.267196/

 

bare minimum you want the 2 looms back to the ecu, ideally grab the other bits I mention above. You dont need the main loom in the bay with all the headlight plugs etc on, only bit from it you need is the T14a plug I mention as then you can splice that to your conversion wiring loom and then the main ECU sensor harness with the smaller plug on it drops in with only some or no modification depending what you do about MK1 sensor wiring.

basically follow the loom from small ecu sensor down, you'll find the 14 pin plug I'm on about, you cut the matign plug for this off the donor car with a good length of wire which you then tap into your old engine loom. The more length on the wiring you get the better, if you go too short its going to need a few splices to get it to reach. If get enough to reach the fusebox direct you can even crimp new pins on have no spliced joints at all, though for that you need the pins and the crimp tools to do the job, up to you

 

On the later cars its near the battery, earlier models its inside the plastic loom channel about half way up the chassis leg

 

yeah the 2 looms that plug into the ecu will disconnect and come out easy peasy. The T14a looks like this:

 

sounds like the 3 pin plug into the back fo battery fusebox for the abs/fan? you dont need anything else from the main loom apart from the sections I mention. You can drag a load more mk4 wiring out if you like though its handy for spares

 

Nice a MK1 van, dont see too many of those about!