By Dan Heil

I broke the instrument cluster circuit board. Now what?

You can probably epoxy the broken board parts back together and then solder copper wire to bridge the traces.

If your in as far as the circuit board, take a little extra time and clean the whole thing up. I took apart and cleaned 2 guage assemblies last fall. I wrote down what I did and the screws I needed. I replaced all screws with Stainless Steel, which were available at my local hardware store for about $10 total. You can also get the screws cheaper at www.olander.com

FYI a #6 screw is an american sheet metal screw, a M4 or M6 is metric machine screw, just incase you did not know.

Refurbishing the instrument cluster

Disassemble carefully removing the old and rusted screws. A pair of small channel locks is good for removing rusted screws. Carefully drill out the 5 rivets holding the circuit board to the metal backing plate.

Leave the 3 plastic Blue/Green Lamp domes in place if possible, If not: Note (write down) the orientation of the 3 plastic blue/green lamp domes. Then drill out the backside plastic (rivet like) for the 3 plastic blue/green lamp domes to remove them.

Clean all the plastic parts in sink with dish soap. Let dry. Fix any broken screw holes with epoxy, re-drill if needed.

Clean the backing plate of rust, dry, then paint (silver or your choice).

Note the direction of the fuel/temp gauges to the single and dual contacts. Remove the fuel and temp gauges from the small circuit board. Clean the circuit board carefully, not damaging the delicate wire and switch assembly. Clean with a dry scotchbrite pad. Coat traces as below*. Remount the fuel and temp gauge.

Scrub the circuit board with a stiff brush and kitchen cleanser or Stainless and copper pot cleaner to clean off any Green coating or ?? colored corrosion on the circuit board. Wash good to remove cleanser. Dry. You will probably have to re-clean the copper traces with a dry Scotchbrite pad. Wipe down with rubbing alcohol.

*When dry lightly coat the NON-CONTACT areas of the circuit board with varnish, do the fuel temp gauge circuit board also. This will limit future corrosion of the copper circuit. CONTACT areas include the circular contacts for the dash lights, the interface contacts to the fuel/temp gauges (3) and the 2 rivet holes that ground to the backing plate.

Attach the 3 plastic blue/green lamp domes with a small dab of epoxy at each corner, tape and let dry.

The clear gauge faces are attached with the M3 x 10mm machine screws in place of the black sheet metal type screw. The machine screws will thread in to the existing holes with out re-tapping but running a M3 x .50 tap in each of the face mounting holes would help. Don't run the screws in to fast and be gentle with final tightening

Assemble the circuit board to the metal backing plate with 5 M3 x 6mm screws, nuts and lock washers. Reassemble the remaining parts of the guage assembly.

Parts needed. (I used Stainless Steel parts as much as possible)

• 4 (9 total see below) - M3 x .50 pitch x 6 mm long screws for Tachometer mounting into housing.
• 4 - Metric M3 or #4 standard Flat washer, for above screw
• 4 - Metric M3 or #4 lock washer, for above screw
• 5 - M3 x .50 x 6mm for replacing rivets
• 5 - M3 x .50 Nut
• 5 - M3 or #4 standard lock washer
• 12 - M3 x .50 x 10mm machine screw for attaching clear covers to Tachometer housing, speedometer and fuel/temp gauge housing
• 8 - #6 (#8): Phillips Pan head sheet metal screw for attaching circuit board to plastic gauge housing. (2 are for attaching Tachometer to gauge housing)
• 2 - M4 x .70 pitch x 6mm for attaching speedometer to metal back plate