MELBA coach gearbox reverse switch

[solotech]

Hi,

A friend is converting his 88 MELBA coach into a motorhome.

An issue that has arisen is that the reverse lights stay on. We removed the reverse switch from the gearbox. It's in the closed position, allowing 24v to feed the lights. Pushing the plunger creates an open circuit, when the switch is removed. The switch plunger appears to be in contact with a small rod, when seated in the gearbox, which doesn't move, no matter what gear is selected.

Does anyone have a manual for this model, or have any idea as to how the plunger is moved from open/closed/open? The coach uses a Caterpillar engine, with a ZF 6 speed manual gearbox.

Thanks.

[boronia]

Usually this sort of problem is caused by the plunger getting gummed up with old oil/grease and dirt, and not resetting properly. Sometimes there may be a spring inside.

Clean up the area with kero, and apply WD40 liberally onto the shaft. It may require some manual handling to free it up.

[solotech]

Thanks boronia.

It turns out that I was looking at the wrong switch. The ZF reverse switch, for this model, is on the very back of the gearbox. The two pins had fallen apart and the wires, of course, fell off.
No switches in Australia, according to ZF, so new one on order from Germany.

Cheers.