jss

in the efforts to finish my s2 into 951S swap. only problem I have is no tach. I have the 8 flat connector underdash by ecu not connected to anything. can i get some info on this connector

Teddy952

Just last week I got the tach working in my 89S using the flat 8 pin connector in passenger foot well. There are 3 wires connected to the tach within the gauge cluster. The attached diagram is what I used in mapping the wires from the tach to the 8 pin connector. The tach gets +12v, ground and a ground signal from the 'B' connector that is connected to the back of gauge cluster. The ground signal is what the tach uses to register RPM and that is term 3 (grn/blk) on the 'B' connector. Term 3 from 'B' connector in cluster, connects to term 2 within the 8 pin flat connector. Try connecting the tach output signal from the ECU to term 2 on the 8 pin connector. I don't know if you dash cluster is together or not but just to be sure you can check continuity between term 3 on clusters 'B' connector and term 2 on the flat 8 pin connection.

jss

i bought the car swapped already but with burnt motor i replaced everything with turbo s gear and engine harness. the car runs but the cluster has a weird acting volt gauge and no tach. when looking at cluster area someone added 3 wires from tach to the glove box area but not able to tell where they tapped into under the golve box. i did notice that the green/black wire of cluster connect to be cut and the loom side was soldered to one wire going to the glove box area..

also the plug on cluster most left when looking from seat there were 2 other wires cut and new wire ran to glove box area. those wires were brown and blue that were cut and soldered.

when i saw that i tossed out the home made wiring and re soldered the oem harness but now i releaze those were cut on perpose to get to the glove box area.

so lets take green with black wire . what i need to do is take a wire from cluster green/black and run wire to that 8 pin plug? do i do the same with the blue and brown wire?

jss

so after looking at my stock 89 turbo s it looks to be that all late 944 have the 8 pin plug part of the body harness. which is what my 89 s2 also has but i do not have the connecting section which is part of the engine harness which i find weird since i put a 90 turbo harness in there but i dont see the 8 pin connector.
so it seems that I should not have to mod any wiring into the cluster area harness i should just have to connect the body wiring harness 8 pin section and plug into the engine harness 8 pin connect but i dont have this so kinda lost now.

this picture shows on right the connector that is part of the 90 951s harness i installed (engine harness) and you can see how this plug is different when the connector cap on the left from the 89 951s is beside it.



this picture shows the s2 body harness with the 8 pin connector going no where since i cant find its partner.



here we have the 89s harness which its 2 sections which is what i need to make the s2 car correctly work



this is what i need from engine harness to complete the cluster to work but dont have for some reason

Teddy952

The 2 brown and blue wires coming from the 'A' plug (leftmost cluster connector) control the factory boost gauge. If you search for 'boost gauge wiring' you will find a nice writeup explaining how it works and its voltage requirements. Both of the brown and blue wires connect from the clusters boost gauge to the 8 pin flat connector. I don't believe there is any wire color change on the 8 pin plug so just look for the blue and brown.

The GN/BLK wire (tach signal) from the clusters 'B' connector should also go to the 8 pin plug.

Teddy952

I cant see the pics at work.
Quick and easy way to get your tach working....
From the 35 pin DME connector that connects to the ECU, term 21 should have 2 wires coming out on the harness side. One wire is green and that goes to term 9 on the KLR and the other wire is GN/BLK. The GN/BLK wire goes to pin 2 on the 8 pin flat connector and then terminates at pin 3 on the clusters 'B' plug. If you don't have a plug you could test by running a wire the entire length.

jss

the 8 pin plug looks to be only 7 wires in use so since I dont care for oem boost gauge( I am running a standalone vdo unit) that now leave me to 5 wires no connected.

just keep in mine the 8 pin plug I have is body harness only nothing from ecu side of things.

which means since I have the body section of harness this will travel if I am correct to the cluster plugs which means I dont need to tap into that area but to 8 pin its self .. am i correct to say that?

so lets now say if I have to go into the ecu loom I need to tap into the green black wire and then into the matching pin of the 8 pin correct? that leaves me 4 wires still connect which are for?

the issues I am having is no tach or volt meter working correctly

Tom M'Guinn

It sounds like someone hacked up the harness before you got to it and removed the connector with the tach signal. As such, you are probably best advised to forget about which connector you have and don't have and concentrate on making the necessary wiring connections as Teddy has outlined above. When mixing harnesses like this, there is a risk that physically compatible connectors will not be wired to work properly anyway. Sounds like somebody wired in the tach to work as per Teddy's directions, and you unwittingly undid that. If some theory will help, see the link below with details on the tach signal. We don't have a 90 turbo in the US, so I can't confirm for sure it's harness had the 8-pin flat connector, but all the needed signals are on the main DME harness -- you just need to tap into them. By the way, are you sure it's a 1990 harness? Earlier versions of the 951 engine harness had a 4-wire square red plastic connector in lieu of the flat 8-pin connector. Do you have the red one instead?

https://rennlist.com/forums/944-turb...achometer.html

And here are details on the boost gauge. Even if not accurate, it's nice to have operational gauges...

https://rennlist.com/forums/944-turb...e-control.html

I believe the flat 8-pin connector carries the oil level warning sensor too....

jss

the engine has a coding that confirms its from 1990. the engine had this harness on it when i did the swap. it was clearly not taken apart it had all factory hockey tape just like it should.. i will check on red connector if it has or not.

so from all your posting guys the buttonline is that the cluster wiring should be left alone. and all repairs should be done at the ecu harness taping. so if i am correct from what your saying since I i have a spare 951 harness maybe best for me to do clean install is to remove the missing 8pin from that with some wiring and solder those. at which point I can just plug in the new 8 pin from ecu harness into the body 8 pin that I already have.

if i am correct I don't understand why someone cut the cluster area and ran wires from that to the glove box area. would it have not been easier just to tap into the ecu harness and the body 8pin connect that is in close area to each other?

Tom M'Guinn

I just wouldn't make any assumptions about the flat 8 pin connector on the dash harness. Be sure to trace each wire back to the cluster as outlined in Teddy's posts. Otherwise you might end up perfectly replicating the 951 connector on the engine harness side only to find out it is not pin compatible with the dash harness on your car.

As for the wires going toward the glove box, its hard to comment without knowing what those wires were connected to...

jss

i did try them out with meter and they make connection to cluster harness so all is correct there

Teddy952

Ok... so the BK/GN wire from the 8 pin connector shows continuity all the way to the cluster? If so this is the wire you will use to connect your ECU's tach signal output to.
You are using a standalone VDO boost gauge so no need to hook anything up to the blue and brown wires on the 8 pin plug.
There is also a white/yellow wire on the 8 pin plug that connects to the dash's oil level warning light. The other end of the WH/YL wire connects to the oil level sender on the side of the oil pan.
There are 2 black wires on the same term within the 8 pin plug. One wire goes to the factory diagnosis plug and the other goes to the knock control diagnosis plug.
The white/green wire connects to the factory DME at pin 11 and is for 'economy control' not sure what this is but Id guess its for the NA's MPG gauge.
I don't know how close to factory you would like to be but it sounds like you just need to use 2 wires on that 8 pin plug. The BK/GN for the tach and WH/YL for the oil level.

jss

oil level floater is deleted from pan. didnt care for it so will not use that. so looks like the green.black is my new goal to connect. any thought to volt gauge issues?

when the 3 home made wires were tapped into the cluster the volts was at 12 when car running. which is not correct when i reconnected the tapped wires at the cluster harnesses like oem volt went up to 14. which is still not working correctly i think this may be some kind of cluster issue because no other wires are modded. and from what you say there looks to be no wire in the 8pin connector to help with this issue.

Teddy952

It looks as if the voltage gauge has 2 wires connected to it.
Terminal 5 in the 'C' plug (rightmost connector on the back of the cluster viewing from drivers seat) is a BK/RD wire. This wire connects the voltage gauge to the same connection point that the tach gets its +12v from. Check term 5 on the 'C' plug for a voltage reading with key on.

The second wire from the voltage gauge looks to be ground. Terminal 8 on the same 'C' plug should be BR/YL. I don't know for sure if this is the ground for the voltage gauge but it appears to connect to the gauge according to the clusters wiring schematics. Check term 8 for ground.

What does the voltage gauge do that indicated something was wrong with it?

jss

its just locked on to 14v compared to when the 2 boost wires and single grn.black wire were not connected it would be 12.