Will a cluster from a 1987 740 turbo wagon work on a 1988 non turbo 740 wagon ?? Not sure if I will swap cluster for cluster or just gauges from the one to the other. My main need is a correctly functioning tachometer. My tach in the '88 cluster reads too high & is erratic.Also I notice that '87 has battery/amperage gauge which the '88 does not. How do I go about getting just that gauge to work on my '88 cluster ? Thanks Very Much.

If you already have the 87 Turbo cluster, it's worth a try swapping the whole unit. The only thing that is likely to be different is the speedometer, and if they both have the same connector (they should both be the 3 pin type---they changed to 4 pin for 89 or 90 models) the only thing that can happen is that it may read incorrectly. All the other gauges should be the same. I don't believe there is any risk of damaging anything, as all the connectors can only go on one way, though, if I remember correctly, there are a couple of single wires, which it is very important to connect to the correct terminals. If you get one of these wrong, you can burn something up, but that is a risk whether you are removing and reinstalling the original cluster, or swapping in a different one.

If you want to install the voltmeter in your original cluster, that's easy. There is a blanking plate, held in by two screws. Remove it, and replace it with the gauge. Connect the wires to the same terminals as they were on the original cluster, which should be there on all of them.