Dynamic oil pressure system question

[33B]

1987 Passat 1.6 TD CY engine

So this never worked in my car. When someone dropped a NA 1.6 in this car they cut the yellow high pressure wire.
Since then I've reinstalled the turbo with all the original parts oil filter housing oil cooler etc.

I reconnected the yellow wire to the high pressure sender and it goes to the cluster, at first I thought there was no dynamic oil ... board in there but I discovered there is.
So could it be that the board is dead or is there a relay that controls this thing?

Also is there a difference between a gas and diesel Dynamic.. board (i have a suspicion that this is a gas board/kmh gauge)?

I've tried unhooking the yellow wire and holding it over 2k rpm, but like I said it was always disconnected.
And yes there is a signal from the W terminal from the alternator, also the low pressure sensor is working fine.

Thanks

[Tomoturbo55]

I think the board is fried, systems reads rpm either from coil od w terminal, if u Would cut yellow wire the systems Would Buzz all the time cause it has no ground it need ground to stop buzzing,

I dont know about the tacho diffrences and effect it might have gas vs diesel.