Fuse not getting voltage

Looking at the power distribution schematic, it shows that fuse 43 is fed from the main buss bar in the fuse box directly from the battery on it's feed side and then powers the cluster and the OBD sockets power pin as well. I would use the voltmeter to check the power with fuse 43 removed, one side of the socket should then be battery voltage and the other should have zero. If you still only see the 1.7 volts on the power feed with the fuse pulled there is an internal fault in the fuse panel and replacing it would repair it. If however you remove the fuse and have battery voltage now on the feed side then there is a problem in either the cluster or the ALDL socket causing the voltage drop. If you get battery voltage with the fuse removed then I would remove the cluster again and test for voltage at the power wire with it unplugged. That would be terminal 4 and the red/orange and white wire. If with the cluster unplugged you get battery voltage then it is an internal cluster issue.

If you test the first time with the fuse removed and only find the low voltage on the fuse socket feed side I would probably try a test to see if there were other problems. To do the test I would get one of the plug in fuse taps that allow you to add a circuit like the second image. Nor remove the fuse 44 and plug the fuse tap into it. Then plug the 5 amp fuse from position 43 into it and then use the open wire from the add a circuit to power the terminals of fuse 43 and see if the cluster now works. If it does then you could leave that installed or install an inline fuse holder to bypass the fuse socket in the panel.