Oil Filter Housing Wiring

Afternoon Folks,

Sorry for yet again another wiring issue. I have spent the afternoon trawling through hundreds of threads and posts looking for images of peoples engine bays lol before posting as this is an ongoing project which has been off the road a year.

Basically I've found a broken yellow and black wiring in my engine bay which I'm lead to believe is the oil pressure wire for the sensor on top of my oil filter housing. However there is a blue and black wire connected to the 1.8bar sensor. I'm now really confused as every time the engine revs past 2000rpm the pressure buzzer and light goes off. Could it be that the previous owner has confused the two wires?

I now need to make this a little more complicated as I have now taken off the original oil filter housing and replace it with the housing required to fit an oil cooler. I'm also wanting to fit VDO gauges which I have already got from and A4 (92) and want to make sure the wiring is right before I start messing on with the wiring for them.

Would it be any help if I supplied images of the wires and my oil filter housing?

Cheers Richard

Here are a couple of images of the housing and wiring, couldn't help but sneak a photo of the car in as well.

wiring looks ok to me, unsure what the yelow/black wire does but its not for oil pressure. maybe the white switch is the wrong rating for your car, it certainly looks non-standard. it should be a 1.8bar switch there so whip it out (when stone cold) and have a look at the markings on it if any

So the blue wire is definitely for the oil pressure? I'm guessing then that the mk1's never came with a temp sensor unless they had mfa?

I know the sensors are the right ones as I recently replaced them! Thanks for your help so far.

yeah exactly, unless it has the mfa you dont have oil temp wire. if its there usually wire would be green/black.

is the car a carby? if so it might be for that

Yeh the cars a carb, according to the log book its a DX but I thought a DX was an injection GTI lump. However its currently sporting a weber 32/34 with a KnN top filter. I believe I have all the connection points correct for that but just cannot decide what the yellow and black wire is for. Looks like its been there a while tho.

One other question I have is do I 100% need a pressure sender to get the gauge to work or will the current sensor do the job?

dx is injection, so that would suggest someone has swapped in a carb lump for some reason!

you wont get your pressure gauge to work unless you fit a proper oil pressure sensor. VDO gauges run a dual pole sensor which replaces one of the existing sensors. you run 1 wire to the gauge, and the other connection is for the old pressure wire.

if its had the full carby engine loom fitted and the carb was changed to a webber this will probably explain the spare wire, the 2e2 carb the engine would originally come with has a couple of thermoswitches which are redundant when you fit a webber. this wire was probably for one of those switches