XJ-S Instrument Panel repairs

Instrument binnacle
overhaul procedure
The first procedure is to remove the binnacle from the car and strip it down to its component parts. here is how

Good practice: place all the parts in small containers away from your work area as you strip the unit out. try to group them together in part type and order of disassembly to avoid confusion during reassembly. wherever possible label everything

1. Remove the two screws (one ether side) 2 Fig 1 and one in the top finisher 1Fig 1 and carefully remove the surround panels

2. Pop the two end finishers out of the instrument cluster at each end of the warning lights 3 Fig 1 and undo and remove the two screws (large) that fix the binnacle in place 4 Fig 1 Also remove the two screws that hold the warning lamp legend in place

Figure 1

3. Extend the steering wheel to its fully out position and tilt the binnacle forward and down so as to gain access to the rear.

4. Disconnect the two loom plugs and the speedometer drive cable on pre electronic versions and fully remove the binnacle

5. On the workbench lay the binnacle face down and remove the screws that fix the faceplate to the main unit and separate the two halves.

Figure 2

6. Next undo and remove the screws that secure the speedometer monitor gauges and rev counter to the main unit note the location and use of the washers/packing pieces. 3, 4 and 5 Fig 2. Extreme care must be taken when handling these parts as they are easily damaged, as is the printed circuit.

7. Undo and remove the screws that secure the green domes and inspect them for damage If your domes are OK and not damaged or darkened and if you intend to keep the illumination original, clean them out

8. Disengage the illumination lamp housings again taking care not to damage the printed circuit board. 1 Fig 2. Remove the lamps from the holders

9. Undo the three screws holding the earth strap in place to allow easier access to the warning lamps. 2 Fig 2

10. Remove all the warning lamps from the main unit. 6 Fig 2

11. VERY CAREFULLY, remove the PCM from the main unit.

12. With the main unit completely stripped out clean the inside to remove all traces of dust and dirt (and sometimes rust, yes it even gets in there).

13. Remove the spring washers that hold the front faceplate Fig 3 to the front panel and separate the two parts

Instrument binnacle
overhaul procedure

You are now ready to overhaul the individual parts

1. Clean all the plastic parts to remove dirt, rust and grime using a good quality washing up liquid and set them aside to dry. (best to do this when the other half’s round her friends house - you know it makes sense)

2. Take the PCM and carefully mount it on a piece of glass, hardboard or the kitchen work top, using low tack tape (masking) on the corners making sure that all the little connector tags are lying flat (use the work top option ONLY if she is still out at her mates house)

3. Using a pencil eraser or fibre glass pencil gently polish all the tarnish off the connectors until they ar bright and clean.

4. Leaving the PCM taped safely in place until reassembly move on to the screws that where removed from the gauges and polish the mating surfaces to the same degree as the connection points on the PCM

5. Take each of the monitor gauges in turn and clean the connection receptor on each connection pole where the fixing screw comes through the plastic and touches the conductor.

6. If you wish, now is a good time to test the travel of the Monitor gauges but this is optional depending on how confident you are. If you are at all worried proceed to number 8 You could use a 12v power supply, three lengths of wire with crocodile clips on them (red and black for clarity would be good) a potentiometer rated to the senders ohmage and a volt meter (VM)

7. This would allow you to test each gauge to insure that its travel was smooth and that at full power it reads maximum. Test each gauge in turn and use the Schematics on this web site to correctly Identify the terminals polarity. If you’re reading this bit we’ll assume you already have a clear understanding of how to complete the test satisfactorily and so we leave it to you from here on in.

8. Clean the contacts on the revolution counter and Speedometer (electronic ones only) as before with the monitor gauges.

9. Turning your attention to the lamp holders, inspect each one for connector firmness and clean each to remove tarnish etc.

10. Check the green lamp domes for burnishing and cracking, any sign of ether means that they will have to be replaced

11. Once all the parts are clean you might consider coating them with a anti tarnish solution available from most good electrical stockist's such as RS Components or CPC

2. The inside of the main unit also needs to be given the same treatment. Fig 4 with the exception that a good aluminium silver paint applied to the lamp housing chambers helps to maximise the travel of the lamps filament output thus delivering maximum light to the front panel for reflection to the corresponding instruments face. Fig 5