Interior Lights

hvanman · Post by **hvanman** » Fri Jan 13, 2012 3:49 pm

Hi, I have a very strange problem with my interior lights on my 1.7 TZD Turbo Estate.

They do not operate when either front door is opened, however they work if you operate the switch on the light itself, but the door switches are also working fine as the dash door indicator works and the lights-on warning operates, so I can't work out why they don't work when the doors are opened?

Any ideas anyone....

Cheers, Simon

Post by **mat_fenwick** » Fri Jan 13, 2012 3:59 pm

First of all, the door open warning lights are operated by a switch in the lock mechanism, not the one on the pillar. I suspect a high resistance switch which allows the small amount of current to flow that's needed for the lights on beeper, but not enough to light the bulb. Try shorting out the wire behind the door switch to a good earth - if it lights then the switch is your problem.

hvanman · Post by **hvanman** » Fri Jan 13, 2012 5:06 pm

Great, thanks for the suggestion, that door open panel was leading me astray....

hvanman · Post by **hvanman** » Fri Jan 13, 2012 5:46 pm

Well I put the door switch wire to a good earth and no joy. None of the 4 door switches operate the lights.

I put an earth to the relevant contact on the back of one of the lights and all 3 came on, so I am guessing that somewhere there is a point where all 4 door switch wires join onto a feed to the lights and this is at fault, does anyone know where this might be located?

Thanks, Simon

Post by **mat_fenwick** » Sat Jan 14, 2012 9:04 am

Onto guesswork here, but I'm now wondering whether the problem lies with or around the interior lamp delay unit? As there is obviously some current passing through the switches, and a corroded high resistance contact is less likely inside the car.

If the lights work as expected from the rear doors that would tend to rule out the unit itself. I don't know at what point the wires split to operate the lights on beeper, but the problem would appear to be after this point...

hvanman · Post by **hvanman** » Sat Jan 14, 2012 9:38 am

Yes I had a look at the wiring diagram and that seemed a likely culprit, as the rear doors do not operate the lights either, so it seems to be a common point if I can find it!!

KevR · Post by **KevR** » Sat Jan 14, 2012 9:42 am

Is the delay relay the one attached to the back of the dash between the top of the glovebox and the side of the heater control unit?

I hadn't realised the door open light was controlled by a separate switch from the interior lights - my driver's door light has been permanently on for months, and I'd been scratching my head trying to work out why!

ken newbold · Post by **ken newbold** » Sat Jan 14, 2012 9:52 am

KevR wrote:Is the delay relay the one attached to the back of the dash between the top of the glovebox and the side of the heater control unit?

Yes

hvanman · Post by **hvanman** » Sun Jan 15, 2012 5:21 pm

Thanks for the location advice, nice easy fix, the plug to the unit was half out! However also found one of the door switch contacts had got some light rust and was not making contact, so a quick clean and all doors working lights properly now. Simon