What connector is missing (1992 instrument cluster)

[MartinThomassen]

Hi,

I have this semi running project 940 (1992 SE sedan) sitting in long time storage at a friend. The car has been engine and transmission swapped by the previous owner. From the factory it was a NA 2.3 automatic, but has since gotten a B230FK engine and M90 transmission.
It has the classic intermittent/non working speedometer and fuel gauge, so I pulled the instrument out as I either wanted to try and fix it myself or have it done by a professional I know, but never really got around to it
I then had to move the car last weekend for the first time in a couple of years the, and I didn´t bother to install the instrument cluster. The car fired up and was running half decent, but when it was time to move it, it lost all power, would stall, and I could barely move it from one spot to another. I instantly thought it might be due to a clogged fuel filter as the fuel is a couple of years old.
I then found that one of the pressure hoses going to the intercooler had popped off (for some reason the clamp was missing), and after putting it back on the engine was once again running decently

While researching possible causes of the above poor running I read that the alternator won´t charge if the instrument isn´t connected, and after "fixing" the problem I could also verified this with my DMM.
My intention was therefore to plug the instrument back in, as I guess the ignition system will have a hard time doing its job when only being powered by the battery, to see if this would fix some of slight misfiring the engine still got.
But when reattaching the instrument I got in doubt regarding two of the connectors, one being a black one pin connector which could seemingly be placed on two adjacent spots on the instrument cluster (one being marked with an X)
The other one just seemingly didn´t fit at all.
I´m not entirely sure that this cluster originates from this specific car, but at least the dates on the cluster (1992 05 15) and the first registration date of the car matches (1992 09 17) somewhat.
But I still don´t understand why one of the connector don´t seem to fit, and which of the two pins the black connector should be plugged into.
Can anybody here help to shed some light on what this connector is supposed to do (everything in the instrument did seem to work with the rest of the connectors in place)?

I have marked the connectors with yellow in the attached photos.

Thanks

[MartinThomassen]

So, for some reason it seems like the wiring harness behind the instrument cluster isn´t factory. I found a wiring diagram of a 1991 940:
http://www.v8volvo.se/mekartips/volv...%20Michell.pdf
and it seems like the missing 4 pin connector (G) is for the rheostat/instrument dimming switch and the clock adjuster. The 1 pin connector (E) is for the fuel injection ECU and O/D relay - being a automatic from the factory this seems plausible (white/violet wires).
The 6 pin connector on the wiring loom seems to be part of the ambient temperature sensor gauge according to a 1994 wiring diagram I found:
https://www.scribd.com/document/5479...Wiring-Diagram
So I might be able to ignore these after all

[MartinThomassen]

Double post

[Laird Scooby]

You need to find a wiring diagram for thw 1992 940, they used a unique instrument cluster and there are things in places on them that won't connect from other years. In other words, if you can't fix your instrument cluster, you'll need a good one from a 1992 car.

If memory serves, those two male connectors are linked internally but check with your DMM first.

[Forrest]

The early instrument clusters did vary a bit between model years and weren't necessarily compatible. I think one of the FAQ files has some information about interchangeability of clusters/instruments.

The purple/white single connector can go on either of those outputs from the speedometer. It provides a speed signal back to the ECU. The other one is only connected if the car has cruise control.

The attached picture is of a 1994 cluster with ambient temperature gauge installed. It does not show the 4-pin connector you cannot find, so you really need the wiring diagram specific to your model. On cars with ambient temperature sensor wiring but without the gauge installed the connector is left taped-up and unconnected behind the cluster.

If you have transferred parts/sensors from another model year you may find some of the signals incompatible with your cluster.

Good luck getting it working.