These troubles could be a LOT of thngs
WIPERS
Could be a bad motor, bad connections in the BULKHEAD CONNECTOR, bad connection at the fuse panel, bad connections at or a bad switch Could be too much friction in the linkage and wiper shafts -- a common problem
GAUGES It's probably time to FIRST overhaul your cluster and then work from there.
My 67 has TWO circuit boards, and so some of the circuits have to "jump across" from one board to the other
Loose broken pins on the connectors
Poor grounds between the boards and the cluster
Poor ground between the cluster casting and the body
Poor connections at the limiter "socket"
Poor connections AT THE GAUGE STUDS
Take everything apart and clean the cluster casting. Take something like scotchbrite and buff clean the copper pads where connections are made, the gauge studs, lamp sockets, etc
Solder/ replace/ repair the connector pins. Mine were so bad I abandoned 'em. I just soldered wires to the copper traces and ran them off to a "Molex" style plug I bought from Radio Sh$$
The limiter socket. Mine has three brass fingers and NONE of them made reliable contact with the PC board. I soldered the brass to the board. You may want to do so by using short lengths of jumper wire.
And of course the limiter itself is suspect, either build yourself an electronic one (Google) or buy one of the aftermarket electronic replacements
Gauge studs. Replace the fake nuts with real nuts, probably would not hurt to use star washers. Clean the pads under the studs, and use a tight/ loosen /tight motion to "scrub" the connection clean.
Cluster ground. Put a pigtail wire under one of the cluster case screws, about, say a foot long. Put an eye on the other end, drill a hole in your colum bracing behind the cluster and ground it there.
Other problems with the gauges are poor connnections IN THE BULKHEAD CONNECTOR, bad connections at the sender end of the wire, and bad/ improper/ damaged senders.
You can ruin a temp sender by overtightening it.
The fuel gauge sender MAY NOT be grounded. Clamp or solder a wire to the fuel nipple coming out of the tank, and run a wire over to the body, grind it clean, apply some dielectric grease, and ground it. The factory "grounded" them with a clip on jumper that went around the rubber connector hose. (Rhetorical) What makes you thing the supply tubing is better grounded than the tank? It's rusty, just like the tank. Underside of the car is rusty, just like at the tank!!
Other than the above, the tank sender could be a poor quality repop (prevalent nowadays) the wiring up to the gauge could have a bad connection. (Clean the rear harness connection in the "kick panel." Remove the kick panel, find the harness connector, and disconnect/ reconnect it several times to "scrub" the connectors clean. Examine with a light. "Feel" how tight it is. Then put some dielectric grease on and reassemble.
YOU CAN CHECK both sender wires. Pull it loose at the tank, clip lead it to a GOOD ground, then go up front and pull the wire loose at the gauge, and check on your low ohms scale.
Same thing on temp sender.
DON'T DISCOUNT that one or both of the gauges themselves could be out of calibration.
You can check the fuel gauge for rough calibration by substituting resistors for the sender.
Redfish can correct me, but I believe these values also work for the temp sender
The values are
L = 73.7 Ohms (empty)
M = 23.0 Ohms (1/2)
H = 10.2 Ohms (full)
