The MGA With An Attitude
WOOD DASH PANEL Installation In The MGA -- DT-200
For the MGA a wood dash panel is strictly a matter of personal taste. It was never installed by the factory, but could be a period correct accessory, possibly even dealer installed. There were many sources for an accessory wood dash panel during production of the cars and continuously in all years since production ceased. Most of the commercially available panels are similar in appearance, following the original dash shape and location of instruments and other standard devices. This makes it particularly difficult to prove one way or another if a recently purchased wood dash is or is not period correct. As such, a wood dash panel will usually not cause deduction of points in concours judging, except on the basis that it was not a factory supplied part.
There are a few gross errors that can be made while installing a wood dash. The wood dash panel should replace the original steel panel, with all of the instruments and switches being transferred to the wood panel. Instruments are to be installed from the front and clamped in back, same as original installation. If a wood panel is applied as an overlay on the front of the steel dash you're screwed, because the chrome trim instrument bezels would be behind the wood panel, and the instruments might be impossible to service without removing the wood panel. Aside from the fact that it looks ugly, the overlay wood panel would definitely not pass concours judging.
Remember the steel dash is stamped with front recessed pockets for the instruments and for most of the switches. This is not just for appearance and styling, but it also makes the dash panel stiffer (so it doesn't flex or vibrate or bend easily). These "counterbores" can be reproduced in a solid wood panel by routing around the openings to produce similar recessed pockets, but it is seldom done. For a panel with thin wood veneer overlay it would be impossible to make counterbores that look good, as the process would expose the underlying wood panel in a different material. In most cases a wood dash panel is left flat on the front side, and the chrome trim bits sit proud on the flat surface. This gives the wood dash an entirely different appearance. But not to be terribly concerned, as the wood panel itself is significantly different in appearance from the original steel panel. That is after all why the wood dash has some appeal to begin with.
The next concern is that the two smaller instruments are side lighted from behind the panel. This requires a local area of the wood panel to be almost as thin as the steel panel. If the wood panel is not counterbored in front, then it has to be counterbored in back around the two smaller instruments. This may also require a small pocket to one side for clearance for the illumination lamp. A counterbore all around the instrument may present a problem with the mounting clamp. A possible solution is to have no counterbore in back, but only a pocket at one side for the illumination lamp and space for ingress for lighting at one aide of the instrument.
Many of the switches and pull cables have a similar problem with a thick wood panel, so some or most of those mounting holes would also need to be counterbored on the back side. The turn signal indicator lamp is secured in the dash by a thread on the colored jewel, which is not long enough to accommodate a thicker panel. The map light lamp socket originally plugs into the steel dash panel and the wood dash must have a suitably sized hole in the wood to hold the lamp socket. The steel dash is secured in the car by three screws at the top and four screws at the bottom, so the wood dash needs to have metal brackets in similar locations to accept original mounting hardware.
Electrical grounding of the devices is not such a problem as you might first think, because most of the devices do not require grounding on the dash panel. The four instruments each get a black ground wire from the harness to be attached to the mounting bracket so the lamps will work. The only instrument that has electrical function is the fuel gauge, and that one is used a junction point for green power wires and black ground wires. Only two dash devices are originally grounded on the steel dash panel, the turn signal indicator lamp and the map light. For these you need to add a grounding wire to the lamp socket.
You don't need to spend much time on your back rewiring the dash. Install all of the devices in the dash panel on the work bench. Then install the dash harness, also on the work bench. When you take the dash to the car you can sit on the tunnel with the dash face down on your knees to do the rest of the main harness wiring connections. You then offer up the whole dash assembly to the body, at which point you may need to get underneath to install the three screws up top in back, and then the four bottom braces with the heater control panel. One of the top screws is above one of the large instruments, so it may be more convenient to remove the instrument while installing that screw.
Once the dash is installed, the vapor pressure signal pipe for the temperature gauge has to be passed through the bulkhead to connect to the the engine, and also the oil pressure signal pipe, the starter and choke control cables, and the heater air and water control cables.