Scottyp

So basically i need to continuity check the speed input signal from the connector in the back of the cluster, to the speed sensor on the transmission? If that all checks out then pull the sensor with the green dust cover out in (the photo attached) and check with a multimeter while spinning it? Looking in the R34 Manual I cant seem to find a pin number or wire colour for the speed signal input into the cluster connector or any wiring info On the speed sensor on the box? There is a small earth strap looking connector on my Diff nose is this the signal wire on the diff you were refering to? Its likely ABS was never working then ... i do have the module/pump under the bonnet which is all plugged in. But dont seem to have any ABS function i honestly cant remember using my brakes enough to trigger ABS when the car was NA, nor can i recall an ABS light in the self test on start up.

i dont have this module in the photo (E) TCS/ABS module...or any wires under the glove box leading to a module other than the ECU seems like it is something i should have... that would explain the no ABS

So i have been trying to study the wiring diagrams, im thinking of starting from scratch... as i think i have gone in guns blazing and missed vital checks.. so i will start again this week . Obviousy firstly checking the power to the speed sensor itself, and checking for continuity on pin 29 ( Vehicle speed signal ) ? Followed by checking the wires in the back of the cluster. Could the fault be caused by a malfunctioning ABS System?, or is my ABS system malfunctioning because of the Speedo fault.. One thing i have noticed just today is there is ABS light on the dash when the vehicle does its normal self check, after noticing this i went for a slow drive down and road to see if the ABS was still functional, and the wheels indeed locked up, pedal doesnt pulse at all. So theres no ABS either is there an easier way of starting the diagnostic process over again? As i now have to work out if the ABS issue is related

So i have had another look underneath and found the second plug you are talking about i was looking at the first one closest to the engine... further back i noticed the second one with a green dust cover over it unplugged it and gave it a clean, re connected it and the only thing i can find with it, is the sensor doesnt click in i can just pull it out theres no release tab for it? However it still seems to plug in fine just thinking back to what you’re saying about the dash, is it worth trying another cluster? Or even another loom? Maybe its something so simple ? Is it possible the clocks on the back in the cluster have gone? and how about ABS side of things? Like i said The loom seems okay no crushing or cuts breaks etc but if there was a short somewhere? I get motivated to fix it and then give up to easily and then try again and repeat haha. And this has been going on since september 2016.. ( i was wrong on my time since the conversion) Would be a great accomplishment to find the problem after all this time but i dont think my skill level is enough. Yet not many places out there that could do it either..

Thanks heaps for the information ! Appreciate it I might have another look today and double check. I do recall a small plug on the diff, but maybe i am looking at the incorrect sensor on the box. There are a few sensors on the loom in the engine bay that dont match up to anything but im sure they are unrelated to the speedo as nothing runs into the engine bay for the speedo function. And ABS has nothing to do with the Speedo on these do they? I mean im sure the ABS is all plugged in as it was before. But that doesnt seem like my issue sounds like a cluster or speed sensor problem its still on standard boost and i drive it like a baby. Box still feels great! again appreciate the help! Probably the most help i have had with the issue. I was willing to pay someone to fix it as im terrible at electrical faults but i cant seem to find anyone in Melbourne that can pin point the issue i will have another look underneath this afternoon and give that another go Cheers!

Thats the strangest thing the only thing existing is the Chasis everything else supports the motor has had me stumped for months

Yeah had the loom out and checked it, all looks okay put it back in and ran it back through the car and all seems fine. Sensor seems fine. All clean inside pins are all straight sprayed electrical cleaner and all seems well there... I envy good auto elecs mechanic by trade but this stuff just baffles me!

Sorry probably should of mentioned that its factory manual has RB20 box in it

Hey all new to the forum, just wanted to see if anyone had had a similar issue when doing this conversion, i have put an RB25DET into an R34 GT, it was a complete motor loom and computer.. only thing thats the same is the car itself..completed it last september, car runs drives fine no issues with boost or any driveability issues however i have lost my speedo and odometer. Everything else on the cluster works fuel, temp, oil pressure etc but no speedo or Kms has anyone got any insight on this? i have been using a temporary GPS speedometer in the mean time but i would really like to get the original speedo working again Appreciate any help i can get! Cheers