Lower two gauges -- fuel/temp both dead

Greetings, all..

This might have been addressed already, but I haven't found it, so my apologies if it has.

1994 Caprice wagon.  Speedo, odometer, voltmeter and oil pressure all work fine; the lower two gauges, fuel and coolant temp, both quit.  I've not only had the gauge cluster out and replaced, but also tested professionally; the original cluster tested fine, and the new cluster (since sold) made no difference.  Apparently, the trouble is in the car itself.  

Possible items of interest, could be meaninglessly coincidental:  they first went out nearly a year ago; at around the same time, a new stereo was installed, the climate control was moved down into the lower slot (where it belongs if you ask me, thanks to theDetailSS for the bracket), and a few months after that, LEDs were installed.

Many thanks in advance to anyone able to point me in the right direction!

A few thought, not sure if any will help, but here goes.

I would change the temperature gauge sending unit on the passenger head and check the wiring. I think it is one green wire. I would also check the ground and wiring that goes to the gas tank. It located driver side by rear bumper.

Also, the digital display units are a pain. When you change radios many times that effects the dimming of everything on the dash.

Good Luck

Tom

I would agree with the ground check. I do not have the schematics for the cluster, but the two gauges may use the same ground. The chances of both gauges losing their inputs at the same time is low. You may have even bent a pin on a connector (I did that with LED headlight connectors...they did not work).