There is a good chance that someone installed a gauge cluster into a vehicle that only came with warning lights on the assumption that the wiring was the same. It is similar and easy to correct, but I'd say you need to start with a factory shop manual. It will show you the correct wiring. If it was a warning light car, the oil pressure and temp sender are switches, not variable resistance senders. The shop manual for a Malibu will work just fine. The tach gets its signal directly off a terminal on the distributor. In theory, you need a little in line filter to go between the tach and the distributor, but I've seen cars without the filter that work just fine.
The classic answer to any question that includes a lot of unexplained electrical phenomena is "check your grounds." There is one large ground for the dashboard, running to a lug on the left side, just above the parking brake pedal. If someone disconnected that for some reason and didn't reconnect it, your gauges are going to act very strange.
Welcome to the site, Eugene. Check the ground that Mike mentioned above. Also check to see if the body ground wires were hooked back up after the engine swap ( common mistake). They run from the back of the head to the firewall. Look for a braided wire. If that doesn't help, push in on the lower right corner of the gauge pod- that's where the connector is and it can get loose. If pushing in helps, even for one of the gauges, then it indicates that the connection is weak and needs to be cleaned/tightened. Let us know, and we'll get you info on how to fix it.
Temp gauge might just be that it is not hooked up. Look for a single green wire between the #1 and #3 spark plugs ( on the driver's side). Gas gauge could be a bad sender or bad ground by the gas tank. Speedo is mechanical, so no electrical gremlins here. Could be it's not hooked up ( check rear driver's side of the trans), cable broken, speedo gear stripped.
You'll probably have to end up tackling each of these as a separate problem. That's part of the fun of owning an old car- learning new stuff, getting the satisfaction of finding and fixing the problem, and having the knowledge to fix it or similar problems in the future. Enjoy the adventure:nanawrench:
thanks for your help this isn't my first time at the rodeo will look for grounds and loose connections first,then check engine sensors to see if there switches or resistors can any body give me exact location of oil and temp sending units engine loaded with pollution junk and extra wires under dash THANKS AGAIN
I had the same problem no oil pressure no volt no fuel no temp. Once i opened the dash n messed with the gauges i realized the wire socket that attaches to the rear of the clusteer wasnt attaching good.