Interior lights not working intermittently

[christiant]

Since sorting out all major issues, started to look at others. So my interior lights sometimes work, sometimes not. All fuses are intact, all switches on the doors OK, just no power to them. Is there a relay and where do I star looking?

[Adam Boswell]

Since sorting out all major issues, started to look at others. So my interior lights sometimes work, sometimes not. All fuses are intact, all switches on the doors OK, just no power to them. Is there a relay and where do I star looking?

Mine was like this then dead one day. The map reading light still works but that's it

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[christiant]

Any of mine either work or dont, and it is intermittent.

[johnnyroper]

I would hazard a guess and say timer unit in fuse box at fault as thatââ,¬â,,¢s what controls them if I remember correctly.

[Adam Boswell]

I would hazard a guess and say timer unit in fuse box at fault as thatââ,¬â,,¢s what controls them if I remember correctly.

Sounds plausible. Assume it's one of the relays ....any idea which one? My fuses are all ok, visibly the door switches are all ok, and the map light is off the same circuit and it still works.......

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[brianh]

I think you will find the timer unit is the same one that does the flashers on the mk2, its part of the fusebox, not a relay plugged into the fusebox that you can replace, its a case of replacing the fusebox if thats where the fault lies. Ideally you need to get the fusebox out and monitor whats happening on the output from it to see if thats where the problem lies. But to do so you need to know what pins your looking for (that info should be in TIS if you have access to it, under the wiring diagrams).

If I get chance will have a look, but it won't be tonight!

[johnnyroper]

Sounds plausible. Assume it's one of the relays ....any idea which one? My fuses are all ok, visibly the door switches are all ok, and the map light is off the same circuit and it still works.......

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Itââ,¬â,,¢s the complete fuse box assembly,there are external relays but a lot are internal ones mounted on the board. If it is knackered then itââ,¬â,,¢s a fuse box change job.

[brianh]

Just looking at this again, you say no power to them - do you mean the door switches or the bulbs by "them"

Note that if a door switch is stuck permanently in the open state that it won't cause the internal lights to come on, they go off after approx 10 minutes if the door is left open anyway. You say the switch is ok visually, but have you actually checked its receiving power to it with a multimeter?

Looking in TIS it shows the accessory delay relay is k126 on the lighting circuit - this isn't shown in the relays layout elsewhere in TIS, so is part of the box as stated above. My TIS only goes upto 2003 though, so if its different after that (doubtful) then can't advise further. Additionally it shows k96 is the lighting delay relay - I would guess this is what keeps the light on after you close the door, the first one is what keeps power to the windows lights etc for a short time after you switch the ignition off.

Output is on connector C4 - this is the one on the front of the fusebox, lefthand side, bottom connector as the box sits in the car, pin 2 - this is the one with the brown/yellow cable on that connector, That should goto ground via the electronics inside the fusebox for the delay so you won't see 12v on this line directly, it then exits via connector c4 again on pin 4(Brown wire). If you aren't getting a link between the two pins this would give no lighting I think.

pin 4 of connector C7 (this is the top connector with 8 pins) look for the red/black wire - this should see 12v if the lights should be on (test with a door closed and open see if theres any change).

The door light switches go back to connector c1 (this is the one in the middle of the bottom 3) and are fed from fuse f55. Assuming its a RHD car we are dealing with (as LHD is different!) then the righthand front door is pin 7, the rest are pin 6 - Both are Brown/Yellow cables and you should see 12v on them if the corresponding door is open.

If you can't see the expected voltages on the c1 connector then theres a wiring fault or switch fault somewhere in the door switch cables. Given none of these move except for the tailgate one (which works off a switch in the tailgate latch) its unlikely to be broken wires in the door gaiters, but I would have a check of the tailgate wires if you haven't done so recently.

Do any of the lights come on if switched to manual/always on? I'd find it unlikely that all the bulbs were blown, but if they don't come on in that state it would suggest the timer delay part isn't the fault, as this setting bypasses that ground route. it doesn't bypass the timer though.

Hopefully the above makes some sense, its easier looking at the diagrams to work out whats going on.

[brianh]

Also if you do go down the fusebox route there are different ones depending on the type of engine and spec of vehicle, so make sure to get a matching one.

[Adam Boswell]

Thanks Brian, that's a comprehensive list of things to check.

In answer to your first question I haven't done anything other than a visual inspection so haven't had the multimeter out yet. Il take the switches out and check them at the weekend.

You make an interesting point about the bulbs, potentially they could have all blown, the map light works manually which seems odd as its on the same circuit so I couldn't understand why the courtesy lights don't work, but I agree would be odd for them all to have blown

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[brianh]

Dunno if all the mk2s are like this, but mine has bulbs in the front footwells, bulbs on the door cards, and the roof ones so find it unlikely that you'd have all of them blown, though i have found every one of a high level brake light blown (all 5 bulbs!) so its not impossible. Hopefully you can narrow it down a bit further.

[Adam Boswell]

Dunno if all the mk2s are like this, but mine has bulbs in the front footwells, bulbs on the door cards, and the roof ones so find it unlikely that you'd have all of them blown, though i have found every one of a high level brake light blown (all 5 bulbs!) so its not impossible. Hopefully you can narrow it down a bit further.

It's the wife's car and she never goes anywhere at night, or very rarely so it's not a priority but I'll have a gander at the weekend

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[christiant]

Looked at the diagrams brianh sent over. I have a suspicion it is the timer.... Will further look at it. I have to do the dreaded door circuit too, as central locking works from the fob but not on drivers door, could that be related? I guess I will have to have a wander with the multimeter.

[brianh]

The central locking not working on one door is either a dead lock motor or a broken wire in the door gaiter usually. Wires being the more common cause.

[christiant]

So had a play around all the fuses and traced connection from light fo the fuse and earth and all comes out OK so I presume it is the timed relay. Any way to bypass this?

[Adam Boswell]

So had a play around all the fuses and traced connection from light fo the fuse and earth and all comes out OK so I presume it is the timed relay. Any way to bypass this?

This is a good point, there must be a way to bypass and stick another relay in

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[johnnyroper]

So had a play around all the fuses and traced connection from light fo the fuse and earth and all comes out OK so I presume it is the timed relay. Any way to bypass this?

I would think if you have an understanding of electronics and can locate which relay on timer board controls interior lights then you should be able to solder some wires to board and mount an external relay,assuming it is the relay that has failed and not electronics on the board controlling the relay.

[christiant]

I personally do but I havent got so much time to fiddle around with it, I might go with a whole new fusebox. Would they be expensive new as I wouldnt trust a second hand one? I have to carry a torch at all times now

[Adam Boswell]

As the nights get earlier it is starting to pi$$ me off, putting 3 kids in car seats in the dark is no fun at all!

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