I will get this written up and included in the FAQ's when I can but work has me by the throat for a while...

I now have a 1992 745 that has a cluster from a 1994 940 and everything works. I reported not long ago that the work around that Karl Nitz shared with me did not result in a working fuel gauge. I had performed the work around which involves severing several traces, adding two jumpers to the circuit board, and adding a capacitor from the 90/91 circuit board to the 93/94 circuit board, but the fuel gauge always read full.

Steve Ringlee recently worked on comparing the wiring diagrams from the two "eras" of clusters. His efforts rekindled my interest. Emails passed back and forth and I once again contacted Karl. The result was sorting things out and we now have the solution.

The short story is that the work around Karl shared does work, but it also has to include the addition of the 91/92 fuel gauge to the work on the circuit board. It is not as easy as a simple addition of the 91/92 gauge to the 93/94 cluster.

The 91/92 fuel gauge has four connections the 93/94 has three. The 93/94 circuit board has the fourth position, but the white plastic of the cluster does not have the hole for the screw to pass through. You need to drill out the hole. I used a #21 drill bit but a 5/32" bit will work fine. You need to remove several components to peel up the board and then drill the plastic.

The early fuel gauge does not provide clearance for the later clock that is in the 93/94 cluster. So you need to transfer the clock from the 91/92 cluster to the 93/94 cluster.

Transfering the clock presents two problems. The first is that the clock has a harness attachment on the back that is not present on the 93/94 clock. You will need to cut off the plastic protrusions on the back of the 91/92 clock. I used a die cutter to remove the plastic flush with the back of the clock- leaving the three electrical spades the only thing protruding from the back.

The three connectors need to be accommodated on the cluster. This involves using a step drill on the white plastic behind the circuit board. The circuit boards are a different configuration in this area so you need to make a hole that will allow the connector clearance but not damage the the circuit board. The step drill works well- the hole ends up being about 3/4".

Of course the connector that attaches to the clock to enable you to adjust the setting is to large to be used so I used the die grinder or dremel to cut it down so that you have the two electrical females isolated. Once you cut it the orientation is lost so mark it for reference before you cut the excess.

I found the clock did not fit in the 93/94 cluster the way it did in the 91/92. There are only two screws that provide the power to the clock but the second hole ended up being about 3/32" off. Once again peel back the circuit board so that you can drill the second hole (the upper one) over size. The circuit board is still off about 3/32" so you need to scrape off the coating on the board and then cut a small section out so the board matches up with the oversized hole in the white plastic.

At this point you should be able to install the clock and fuel gauge from the 91/92 cluster in the 93/94 cluster.

You need to use the clear plastic and the gauge surround from the 91/92 cluster. It would be nice to not have the hole in the clear plastic that the manual clock adjustment stem went through but the 93/94 plastic does not have a filler in the area below the temperature gauge.

You should have an extra black rubber plug from the second cluster simply install it in the hole for the adjusting stem that is not there. Before putting the two cluster pieces together use something (I used black electrical tape) to cover the back side of the second hole through the black plastic so the white light from the gauge illumination does not leak through.

After connecting the cluster harnesses and before securing the cluster by the screws on each side be sure to check to see that all of the gauges are properly illuminated. Sometimes the bulb holders need to be moved to complete the circuit.

That pretty much is what is involved. Please, if you use the procedure described above let me know how I can make the intructions easier to follow. I hope to convert another cluster and do a step by step instructional submission for the FAQ's that includes photos. Your input would be valuable in that effort.

Thanks to Karl Nitz and Steve Ringlee for their efforts in making this happen.

Randy