How to check/repair courtesy/door lights problems

[christheancient]

I am hoping that the moderators feel that the following is worthy of being an 'article'!

As is immediately apparent on reading through the forum, the door lock/courtesy light/alarm set system on the Phase 1 V70s causes many problems and similar questions on the system are asked frequently. All this boils down to the fact that there are no courtesy light switches on the door pillars any more… they’re buried in the door locks as little irreplaceable or irreparable microswitches.

The usual signs that a microswitch not operating correctly are:
1. The courtesy lights stay on.
2. One, or more red door edge lights stay on.
3. When you lock the car with the remote fob, you don’t get a single flash of the indicators denoting that the alarm is set (if fitted) and the little red light on the dash doesn’t start flashing (though the doors do lock).
4. You can’t use the door lock buttons on the front door switch panels (the lock just pops up again)

Different places that I checked/read didn’t seem to have all the information in one place. However, and through having to do it the ‘hard way’, I think I have cracked how to check and effect a repair (sometimes) to the system.

So, hopefully, an easy guide on how to check and repair.

Checking which door lock which is causing the problem.

I originally never thought that there was a comparatively easy way of determining which switch was at fault. But there is. But it relies on the appropriate fuses and relays to be in place and working first (which they probably are)!

The methodology also relies on there actually being a working light in each door edge. When I checked out the car that I had bought, it took a while to realise that there was a problem! The previous owner had removed all the bulbs that were triggered by the switches – and put the courtesy lights to permanent “Off”,

So make sure that you have at least one spare working bulb for the door lights ready to hand.

Start with the driver’s door as that is the lock that gets the most use. (BTW, both front door locks also trigger the footwell light for their side only.

Open the door and check the door edge light.

If there is a working bulb, the light will come on when the door is open. No light is a dead give-away that somebody has taken out the bulb. In that case, you need to take out the door edge light.

Unlike my previous owner who had ‘mangled’ all the lights out, it is easy to remove the light assembly (replacement second-hand lights are usually readily available from a wide variety of sources, if needed). Slide the light assembly upwards and prise the assembly out from the bottom edge. Hopefully the assembly has a bulb holder with a bulb in it. If it hasn’t, put one in, then, hopefully, the bulb should light.

With the door open, flick the door catch in with your finger… fully… it does have a part-closed position (you can pop it back out again, after, by using the door handle and flicking the catch out with your finger again). If the light goes out, the microswitch is OK. If the light stays on, you have a microswitch problem in that particular lock.

Repeat the above action on all four doors and determine which lock(s) are causing problems. (With my car, I found that three of the locks were faulty… but it did, at least, mean one of them was OK!)

Removing the door lock

It is best to use the Haynes manual for guidance on this. However a few points:
1. In the Haynes manual, it writes about removing the screw that holds the bottom of the window guide. Mine didn’t have a screw on the front doors – it was riveted! However, it didn’t affect lock removal and fitting too drastically.
2. The electrical cables to the door lock are a little on the short side and it is not easy to pull the door lock out without detaching the plugs. I overcame this by working out where the cable clips were and pushing the one nearest to the lock mechanism through. That gave enough slack to allow the lock to come out further while remaining electrically connected.
3. For the more technically minded, the Haynes manual does have the wiring diagram of the internals of the lock on page 12-43. The driver’s lock (which does have a little more ‘gubbins’ in it is item 207. You can do testing with a multi-meter using that diagram.
4. There is sneaky little spring on the lock which can pop off – just when you don’t want it to. I only worked out how it was positioned when I got another lock! So, in case it happens to you, a picture of how it fits



Checking and ‘adjusting’ the microswitch operation

There is more than one microswitch in the front door locks… so you need to know which one to ‘jiggle’! We are looking purely at the switch that operates the courtesy light/central locking/alarm set switch.

The picture below shows the driver’s door lock. The others are fairly similar in layout.



With the lock in the ‘door open’ position use a thin-bladed screwdriver to gently operate the microswitch by pushing the actuator button in. Hopefully, the door edge light should go out. If it doesn’t, the switch is broken… and it cannot be repaired/replaced and a replacement lock is needed.

Now disconnect the electrical plugs to the lock.

At this point I should mention that I have read a treatise where the guy actually dismantles the lock (difficult as some of it is press-fitted) and goes through all sorts of wonderful routines to ‘repair’ the microswitch actuator. If you’re brave, go ahead; but as the actuator is purely a pressure action, with no sliding action, major dismantling and rebuilding is a bit of a sledge hammer to crack a walnut! Also, if you’re like me, you could end up doing it all wrong and ending up with bits left over.

If you now operate the lock a couple of times, you can see which of the many white nylon lumps actually operates the microswitch. Put the lock back to the ‘door open’ state.

What is usually the problem is wear in some of all those nylon lumps means that the particular lump we’re looking at doesn’t quite push the microswitch button in far enough. I suppose that there are various ‘fixes’ that could be applied, but mine seems to working and holding (so far!). With a cotton bud and some isopropyl alcohol, thoroughly clean the face of the white nylon actuator arm where it pushes the microswitch button. This is where you need to build up the surface to nullify the effects of the wear.

And then (well, at least it’s what I did!), carefully build up layers of small pieces of black plastic electricians tape – making sure that they adhere properly (or similar padding) and retesting at each layer by reconnecting the plugs and operating the door lock. Once you have found a thickness that operates the microswitch properly, add three more layers of tape to allow for the eventual compression of the existing layers.

If you are really brave, you may find some alternative method of building up the surface; but that is down to individual taste/ability

Once the microswitch in the lock is working properly, check that the lock is still well-lubricated. Spray-on grease is best otherwise a few drops of light oil in appropriate places will do. WD40 is not recommended – it works its detrimental way into the switch mechanisms! Re-install the lock. This can be a bit of a fiddle with the driver’s door lock as getting the rod operated by the key can be a bit of a so-and-so to get into position.

Once all four locks are operating correctly, the courtesy lights should work properly, the alarm system should ‘arm’ (shown by the indicators flashing once when you blip the remote fob lock and the little red light on top of the dash starts flashing) and the door lock buttons on the front door switch panels should work.

Good luck.

[Gedda62]

Hi Chris, great article which I've bookmarked and expect to have to refer to! I hope you don't mind me asking your advice- my problem is that only one of the red door edge lights work (near side front). All the bulbs are fine. Do you think it will be the microswitch in each door that is at fault as your article implies that the lights more commonly stay on if the microswtches are faulty? I have a 98 T5 CD on 170,000 miles. Otherwise it's in great shape and has been well looked after but I'm a bit obsessive about everything working perfectly!
Cheers!
Ged

p.s the alarm set/interior courtesy lights work fine and (I think) as they should.

[Luxobarge]

Gedda, I had exactly that problem with mine, the red light did not come on. It was the white plastic operating arm (you can see it in Chris's picture) that was stiff on its pivot. I cleaned it thoroughly in spirit, then dried it and worked it back and forth vigorously, while applying spray grease. This freed it up enough so it works 100% now, no problem at all. Note - there wasn't anything wrong with the microswitch itself (the thing with a little green rubber tit on it) but it was the actuating arm that was the cause of the problem - I think this is quite often the case from what I read on here.

Hope this helps - I think you will need to take the assembly out to sort it like I did, but it's not too hard, unusually Haynes is quite good on this subject.

Cheers

[Jules_V70R]

You can also do this, which does not rely on working bulbs :

http://www.volvoforums.org.uk/showth...micro+switches

[PAZ3154]

Sorry to bump this old thread but here's another way to fix this problem if , like me , you're not bothered about the courtesy lights coming on when the faulty door is opened. In my case it was the drivers door causing the problem.
Once you have access to the door lock mechanism you will see the 2 plugs connected to the bottom of it. One with 3 connectors and one with 4. It is the one with 4 connectors that connects to the failing switches. All I did was locate the pair of wires which connect to the courtesy light switches(which were the black & black/white) and cut one of them, thus removing the switch completely out of circuit.
So now the door lock thinks it's closed all the time so no courtesy lights on the drivers door. They still work from all the other doors though. And now my alarm sets properly and I can lock/unlock doors from the switch on the door panel
If you decide to try this don't forget to insulate the wire you cut as there will be 12v on it. I cut it back further in the loom where it was easier to insulate. Also this way it will be easy to re-connect it at a later date if I decide to get a new lock.

[brickman]

Been having electrical drain problems and partially flat batteries the last few months but drawn a blank at anything other than courtesy lights and door lights.

Found that both my rear doors weren't worn, but the white grease in the lock had solidfied, the microswitch's were caked in it. A clean up and some spray grease seem's to have fixed them.

It was your notes about the alarm not arming (indicators flash to confirm) that got me onto it, as wondered why sometimes it did flash, others it didn't!

[George Holmer]

On mine, the three passenger doors operate the doom light from the outside but not from the inside. If I take the door lock out of the door, it works as it should but in the door, it does not. Any ideas?

[colwyn]

Originally Posted by George Holmer

On mine, the three passenger doors operate the doom light from the outside but not from the inside. If I take the door lock out of the door, it works as it should but in the door, it does not. Any ideas?

You may need to adjust the strike plate, I found with my old v70 the boot light would sometimes stay on, if I closed the catch with a screwdiver slowly (one click at a time) the light would stay on but if pressed would turn the light off

[Transcendent]

I myself am in a situation where I had two not quite working door latch mechanisms, one where the door open microswitch was dead (original latch) and a old ebay one i acquired which seems to be intermittent, (breaks when door is shut moderately forcefully...seems to just get stuck some how)

The microswitches are only soldered to a few pads on my old one, unlike the one in your picture which is encased by extra rubber.

Anyhow, they are Marquardt 1055 series microswitches.

http://uk.rs-online.com/web/p/products/8235002/

I think these would be drop in replacements. Doesn't take any disassembly to resolder these replacements. I'll take a few photos of my work replacing the microswitch.

[Transcendent]

OK, so getting the lock switch out from the rubber mounts is very messy requiring cutting and melting the rubber mount that covers the switch terminals. I ended up destroying the donor as my soldering iron tip was a bit ham fisted. My original lock must have been an earlier revision without the rubber though steps require taking to stop the metal corroding.
This pic shows my replaced switch soldered in and working 100%
https://goo.gl/photos/fozznygHf5mqNz288

This shows poor donor
https://goo.gl/photos/oEhEAcQn4h79fHWN8