Mid-journey with a carful of relatives someone asks us to wind down a window and tells us both reverse lights are on full-time.

Pulled over and extracted bulbs (hot!) as a temporary fix.

This has to be the switch Iin the gearbox, right?

I thought they usually failed open circuit?

Yes, most likely cause is the switch on the selector mechanism / gearbox stuck in the on position.

Unplug the switch and see if they go off.

Unscrew the switch and see if it operates by hand.

I'll just see off this Staropramen then see if I can find the switch.

No sign of it from above...

Is it on the 1.2 engine?

Just so you can possibly look on eBay for the same gearbox to see if you can spot it.

Looks to be at the front not far under the linkage arm.

https://www.ebay.co.uk/ulk/itm/272170237332

No it's the 1.4 BBY engine, GRZ box.  Wiring diagrams are telling me there's a relay involved too, in the BCM, which might complicate things.  Also seems like the switch might be at the gearstick, rather than at the gearbox? I'll see if Haynes knows...

Edited 8 May, 201610 yr by Wino

According to Haynes it's an 02R family box, and the switch is "screwed into the shift cover on the top".  Have to have another look now...

 

Ah, no. Tired eyes. Haynes says the diesel 1.4 is 02R, all the petrols are 02T, and its on the front of those.  think I've just seen it, under the back end of the starter.

Pic coming.

 

Photography fail. I thiiiink the pink arrow is pointing at it, but you'd never tell from this pic:

 

 

My gut feeling is that it's going to turn out to be the relay, but access to this switch from below looks like the way to go, tomorrow.

Edited 8 May, 201610 yr by Wino

Just replaced mine as the reverse lights sometimes weren't coming on. Easy job on mine as it's right on the front of the gearbox at the bottom. Needed to swap 'em quick to avoid too much oil coming out of the box. Had some bother though - I bought a cheapish 'Topran' branded one which only worked when it felt like it and the little plastic tag on the side of the switch that's supposed to clip into the plug was not in alignment, so the plug would not click into place. Got ****ed off with it and bought a genuine Skoda switch and it's now totally fine. Cost £41! eek!

Edited 8 May, 201610 yr by TMB

Nice and easy to see in a pic of *just* the box, like the second pic in this listing (good tip hutchy): http://www.ebay.co.uk/itm/VW-SKODA-FABIA-1-4-16-V-GRZ-MANUAL-5-SPEED-GEARBOX-/231300351836?hash=item35da93475c:g:12oAAOSwVFlT4N-9

 

Thanks for the tip about quality of switches Lee.  I'll bear that in mind if diagnostics says it is that.

Edited 8 May, 201610 yr by Wino

If you pull the plug off the switch and the lights go out then it's deffo the switch.

Bulbs are still out, and the undercover is staying on the car for tonight. Will update tomorrow night. :sun:

Even nicer pic for you (GRZ box)...

 

 

Edited 8 May, 201610 yr by TMB

I do like a nice close-up photo of a box...

I do like a nice close-up photo of a box...

 

This morning's updates. VCDS sees the switch as ON, in the Central Electrics module.  No surprises.

A quick look up at the wiring to the onboard supply control unit (aka BCM, body control module), showed me that the wiring diagram I looked at last night may have been misleading me.  There may be a relay involved, but I think probably only when the car has an automatic gearbox (diagram I looked at showed it used for all, wrongly). My car doesn't have a wire on T6o/1, which it would have if there were a relay in use for the reversing lights.

 

So it's looking like the switch, to be confirmed at lunchtime when I can get at it.

 

Edit: Yep, switch unplugged and off it goes.

Found a new genuine switch on ebay for a tenner delivered, can't complain about that!

Edited 9 May, 201610 yr by Wino

I did think it was odd that it should use a relay but the auto transmission explanation makes sense!

New switch went in on Saturday morning. Ran the front wheels up some home-made wooden ramps that give about 100mm lift on the second step. Plenty of room for this job. Undercover off and it's just there in amongst the fan wiring. Cleaned up the area a bit 'cos I was expecting to have to be quick to minimise oil loss, and noticed that the old switch had an aluminium seal washer that the new one lacked. Hoped I'd be able to swap it across quickly.

 

Old switch had grey plastic bits, new one brown, can check part numbers if anyone wants.

 

Anyway, with a 22mm spanner the old one was loosened, and then spun cautiously out, but not one drop of oil came out, which was handy. Seal washer looked awkward to remove, but when I held the two switches side by side with the business ends level, the new switch was the same length from the mounting face without the washer as the old one with, so I concluded it wasn't intended to have one. There was a small amount of some sort of goo/sealant in amongst the threads of the new switch, and no evidence of any on the original.

 

A few observations about gearbox oil changing which I'd scheduled to do at the same visit. 17mm male hex tool required (already had something home-made), drain plug right at the back of the outside/nearside of the box (behind driveshafts), fill plug a little higher on the inside, slightly harder to access above the exhaust. Neither scarily tight, 30Nm is the spec I think. Drained into a nice clean pale-coloured bowl so I could see the state of it. A little darker than I expected, but far from black, at 123k.

Had a funnel with  half a meter of clear hose pushed onto it so I could fill from up top easily, with the emptied bowl back underneath so I'd hear it start to drip out when full.

 

Then I knobbed up, and started refilling without first lifting the rear of the car to bring it horizontal. Not far at all into the second litre bottle it started pouring out!

Because drain and fill plugs are so far back, this isn't an optional step. The car must be level front-back.

Levelled it with a spirit level on the sill top and a couple of jacks at the rear, and this time it took the 1.8 litres expected. Rolling it back off the ramps would probably have done just as well, but then access to screw the fill plug back in would've been trickier.

You lucky thing, oil wanted to gush out when I did mine