All instruments on dash board are out after replacing alternator

Had this problem in a Lincoln. Only car that showed 45mph at a stoplight with brakes on. Odometer kept churning up miles as car stood still. Turned out that Alternator was shorted and although battery kept charge, the alternator case was losing 16 amps into body of car.

I even installed another digital dash. Take off the alternator and have it bench checked.

bad earth behind instrument panel
or corrosion /dry solder
or instrument panel printed board compromised

if happy with inspection of instrument panel
replace the warning bulb
and look at all the door earths and positive wiring

Sounds like the connection on the back side of the instrument panel may have come loose.

Since it's highly unlikely all your instrument panel bulbs are blown (that usually only occurs if a faulty alternator puts out excessive voltage), it can be several things.
Have you checked your taillights and brake lights? Reason I say, many vehicles are designed to not illuminate the instrument panel lights if both taillights are out (a safety feature and tell-tale warning to the driver). If the taillights are ok, it may have a bad dimmer resistor for the inst panel lights, presuming the fuse that controls the dash lights is good. The other possibility is a faulty ground connection to the instrument panel circuit board or wire loom.

Buy a voltohm meter to test voltage at battery. Should be 13.8 to 14.2 volts. Sometimes need alternators need to be "enegized".

I have only ever seen this once before, when an alternator was repaired, badly. The rectifier pack inside the alternator is supposed to dump excess power, if it cannot (it fails or its earth connection is poor) it delivers lots of Alternating Current to the battery. Replace the alternator, a used one from a scrapyard will do.

you have to remove most of the dash then remove cluster from dash they attach threough rear of board

Sounds like the instrument cluster main wiring harness pins on the instrument cluster circuit board. How are you with a soldering gun? Just re-flow the solder on the 13 pins of the main wiring connector on the instrument cluster circuit board, and you should be fine. To get there, you need to remove:
- the lower dash panel under the steering wheel (5 screws),
- instrument bezel cover around the steering column (2 screws),
- instrument cluster cover (3 screws to my recollection),
- and then instrument cluster (4 screws)

If the problem returns or persists, then consider re-flowing the solder on the #331 resistor on the body control module circuit board - there is only one of these on the circuit board. To get the bcm out, remove:
- lower dash panel under steering column (5 screws)
- metal kick plate - 10 bolts and 1 screw (although not necessary, you can get more room by removing the lower metal dash bracket as well - 5 bolts)
- three 10mm bolts holding the bcm in place
- 2 wiring connectors on the bottom of the bcm
- 4 wiring connectors on the front of the bcm - You need to back off the connectors with a nut driver - they were either 11mm or 12 mm

Then:
- remove the metal bcm cover - 3 small bolts
- remove the circuit board - 4 screws
- use a magnifying glass to find the #331 resistor
You're probably best off replacing this resistor while you have everything accessible. (this is apparently the standard re-build fix for these bcm's) I didn't have a suitable replacement, so I just re-melted the solder. After re-installing everything, all my previous dash board gremlins disappeared.

Give yourself 2-3 hours (well maybe 4) for all this.

There are bulbs in the instrument cluster and they are probably bad. You will have to take the instrument cluster out of the dash and take each bulb out individually to see which one is bad then replace it/them and reinstall the instrument cluster back in the dash. It sounds a lot harder than it really is.

Checked Every fuse in the fuse box (no small task).This includes #4 - Power point Instrument Panel, #14 - Day time running lamps (auto lamps doesn't work nor does auto lock), #27 - ignition switch run feed, #35 - Instrument Cluster, #41 - Instrument Cluster, #42 - Delayed Accessory, #45 - Ignition switch run/start feed, #102 - Door locks body security module, #103 - Ignition switch, #110 - Ignition switch, & #116 - Ignition switch. But I also check all other ones as well, they all register OK. AC panel & radio work. Turn signals work. Mileage does not work, trip computer does. So, basically, everything works except auto head-lights, auto locks, and the dash cluster (no MPH, RPM, mileage display, Fuel, Temp, Tran Temp, and Oil Pressure).