Installation Instructions
1969 Firebird U30 Stacked Gauge Installation Instructions
Read all instructions completely before starting installation.
READ FIRST – IMPORTANT
- Designed to work with original Firebird wiring. Original idiot light cars are intended to be plug-and-play because the printed circuit wiring has been adapted to route the existing factory wires to the correct gauge functions.
- Cars originally equipped with Rally gauges require a wire swap at the cluster plug. See the Rally Gauge Wiring Change section before installation.
- LED bulbs are polarity sensitive. If one or more lights do not work, remove the socket and reverse the bulb or socket orientation.
- Always disconnect the battery before working behind the dash.
If anything does not seem right during installation or testing, stop and verify the wiring, sender, ground, and connections before driving the vehicle.
Tachometer Hookup
On the rear of the tachometer there are three terminals:
| Terminal | Connects To |
|---|---|
| G or unmarked | Ground |
| NEG COIL | Negative side of the coil on original equipment coil cars |
| 12V | Switched 12V power, hot only with key on |
If you have an aftermarket ignition system, Pertronix, HEI, MSD, or similar, you may need a tach adapter cable for the tachometer to read correctly.
Common tach adapter part numbers:
Ames PN FM12380 – Factory ignition
Ames PN FM42791 – HEI factory style
NPD PN C-2483-223A – Factory ignition
Parts Place PN FB95974 – Factory ignition
Classic Industries PN FB95974 – Factory ignition
Required Sending Units
| Gauge | Required Sender |
|---|---|
| Oil Pressure | AC Delco D8034 |
| Temperature | AC Delco G1852 with bullet connector, or equivalent Delco unit |
Use Delco sending units. Incorrect senders have different resistance values and will cause incorrect gauge readings.
Rally Gauge Wiring Change
If your car originally had Rally gauge wiring, two wires must be swapped at the plug that connects to the cluster.
Top Row: 1 – 2 – 3 – Blank – 5 – 6
Bottom Row: 7 – 8 – 9 – 10 – 11 – 12
Bottom Row: 7 – 8 – 9 – 10 – 11 – 12
Swap Wire #2 with Wire #7
Installation Steps
- Disconnect the battery.
- Remove the dash face plate, old instrument cluster screws, wiring pigtail, speedometer cable, and ground cables from the headlight switch and cigarette lighter.
- Remove the clock or block-off plate from the dash housing.
- Remove the lens and black bezel from your original cluster by carefully bending the metal tabs.
- If transferring the speedometer, remove the original speedometer assembly and swap the mechanism to the new faceplate. To remove the needle, use two spoons, one on each side under the needle and above the faceplate, and gently pry it off.
- Reinstall the speedometer with the supplied back plate.
- Clean and reinstall the black bezel and lens onto the new housing, then bend the tabs down to secure.
- Inspect your original wiring pigtail. Make sure terminals are clean and bent properly so they make good contact with the circuit board.
- Install the printed circuit wiring to the cluster and stack assembly. Twist in the supplied bulb sockets with the new bulbs provided.
- Install the stacked gauges with the supplied support bracket. One end attaches to the top mounting screw hole in the dash housing, and the other attaches to the metal bracket on the stack.
- Install the two lower screws with washers.
- Reinstall the dash face plate.
- Install the new main gauge housing by reversing the removal procedure. Reconnect wiring, speedometer cable, ground straps, and tachometer wires for your ignition type. Terminals are labeled on the rear of the tachometer.
- Replace the original idiot-light sending units with the correct gauge sending units for oil pressure and temperature.
Important: Remember to reinstall all ground straps.
Final System Check
- Oil pressure should change between idle and higher RPM.
- Temperature should start cold and rise gradually as the car warms up.
- Fuel gauge should reflect the amount of fuel in the tank.
- Tachometer should respond smoothly and accurately.
These parts are new, but proper installation still matters. Do not ignore signs of incorrect operation.