356AT2 rear backup light switch replacement

[roy mawbey]

For James another one of my repairs carried out last year. In this case the rear reversing light had failed a few years ago, the bulb was checked and okay and the wiring and earth appeared trouble free so, I decided it had to be the switch.

After so many years driving my car I had to accept I wasn't sure where it was located. Now as with most things common sense makes things clear. The www.stoddard.com parts catalogue states the late 356A reversing switch is in the "tunnel". Actually, as soon as I realised to make the switch work, the gearstick had to be involved it made it clearer ( along with the help from some kind 356 registry members). When you select reverse and providing you have "dipped beam" headlights on, the long gear stick "shift control rod" that goes from the front "stick connection" through the transmission tunnel to the connection under the removable cover, moves through an arc and in the reverse gear position, the outer diameter of the control rod presses onto the outer cover of the switch depressing it to make the circuit. ( It will not light up unless the lights are on and in dipped mode!)

After obtaining a switch from Stoddard ( bear in mind the switches can be sited in other places on 356 models ) I first removed the aluminium (rubber covered tunnel cover that goes over the gear stick and heater control. To get to the clips I lifted the front floor boards and its easy to lift off the cover( see picture below):

[img][img]http://i443.photobucket.com/albums/qq15 ... ge0025.jpg[/img][/img]

With the cover off you can see the approx. 40mm diameter aluminium switch with the two grey brown wires. However, the location screws for the switch could not be reached and it was necessary to lift the gear stick assembly up and clear of the tunnel. Below a picture of the exposed switch
[img][img]http://i443.photobucket.com/albums/qq15 ... ge0028.jpg[/img][/img]

Before removing the 4 bolts securing the plate with its assembly I took the advise of Mike Smith and scribed around it first and added masking tape to confirm the lateral position in the slots for the 4 bolts. You will find the switch is attached to the gear stick assemblies welded on flap extension. Below a photo:
[img][img]http://i443.photobucket.com/albums/qq15 ... ge0031.jpg[/img][/img]

Then undo the 4 bolts and remove the gear stick assembly. If you cannot clear the aparture then release the shift control rod nut under the rear inspection cover. ( I kept the stick in neutral and it allows you to move the assembly forward when it released. Photo shows the position of the locking nut:[img][img]http://i443.photobucket.com/albums/qq15 ... ge0032.jpg[/img][/img]

When you lift the assembly out you can see the switch screws and notice they the wires have bullet connectors. see photo:[img][img]http://i443.photobucket.com/albums/qq15 ... ge0034.jpg[/img][/img]

The Stoddard switch shown along side the original has only normal wire connections. I clipped the off the bullets and soldered the wires for reconnection. The second photo shows the modification I made with a needle file to enable the wires to enter the switch without being trapped.[img][img]http://i443.photobucket.com/albums/qq15 ... ge0037.jpg[/img][/img]
[img][img]http://i443.photobucket.com/albums/qq15 ... ge0038.jpg[/img][/img]

After changing the switch, I reversed the above procedure making sure to keep all positions the same and making sure the rear shift control rod location nut was tightened. Also make sure all the gears are in the right place. It also gave me a chance to tidy up the tunnel as it looked its age!! The light now works well but as I really never use the car in the dark will it ever prove useful?

Roy

[58A - 71E]

Great write up Roy, and you know how I enjoy these types of thread
Funnily enough this was one of the very first jobs I did on the '58, but good tip about scribing the positions of the bolts holding the gearlever assembly - 'always learning' as Alan says

[john fletcher]

Roy,
As a matter of interest you can re-connect the rev. switch supply to fuse no.1 which is ignition fed and then you will have a safer, more normal system - it is v.useful to know whether the driver in front is going to reverse!
At the moment I think you will find the rev. switch feed is from no.10 fuse which as you say is dipped beam. No.1 fuse supplies the winker and brake light switch from the ignition.

John

[roy mawbey]

John,

Interesting point that John. The original Porsche position for the fuse is on the dipped beam but I agree it is normal these days if you see reversing lights come on in daylight then at least you can be ready with the horn if you are directly behind!!!

Hope the work on your "A" continues well!

Roy