CD Interior reading lamps

[dorsetdave]

The front interior reading lights have stopped working on the 94 8V 2.0 CD. The main front interior light still works fine. Any thoughts would be gratefully received as usual.

[Robsey]

Is there anything else that has stopped working?

First port of call is a fuse..
Possibly No 8

Second, but unlikely is the switch.

If not a fuse, look for the ignition live feed (black wire) or ground (brown wire) connectors on the light panel.

Wiring to light unit are.

Red - battery live for main interior light.

Grey - Is the door pin / light switch controlled ground for the main interior light.

Black - Ignition live for map reading lights

Brown - Chassis / ground for map reading lights.

Strangely Haynes says red wire from fuse 8, which would also affect the radio and sun-visor lights.

Buried on another page it says fuse 29.
And the feed is a black wire.
For interior light with delay and map lights.

[dorsetdave]

Thanks for the information Rob. Don't think anything else has quit. Certainly the radio works. I will check the visor mirror lights.The car is having some paintwork sorted but as soon as I get it back I will follow your thread.

[dorsetdave]

Rob, have just collected the car from the paint shop. Everything works except the front reading lights. Visor lights ok.
I will have a go at it this weekend. Thanks for your suggestions.

[Robsey]

If all else works, then we can assume that the fuses are okay.

Therefore for the map lights / reading lights not to work it would need to be a loose / dirty connector to the interior light unit,

Or both bulbs have failed together.
Not unheard of, but not very common.

[dorsetdave]

Rob,
Following your thread has shown:-
There was no power to the black lead. Looking at the handbook and fuse box cover fuse 8 appears to cover items that are not through the ignition. Fuse 29 shows optional headlamp washers which are not fitted on this car.
Taking the easy way out I wired the black lead across to the red main power leads to the lamp. I removed the "black feed" i.e. it's 12v ignition controlled supply . In effect just jumped the supply, isolating the original to the reading lamps. They now work but not through the ignition which is what I expected. However the light delay no longer functions. The front interior light goes out as soon as the door is closed or switch is deactivated. Tomorrow I will pull the black wire from the back of the lamp and see if the delay then functions. Odd or am I missing something? Quite possible as it's 57 years since my physics studies!

[Robsey]

The ignition live supply is meant to kill the light delay.

That is -
1 - You open the door, and the light delay comes on.
2 - You get in, and then turn the ignition on. As soon as the ignition comes on, the interior light cuts off immediately.

If you do not turn on the ignition, then the delay will run it's full course (10 to 15 seconds).

---------------------------

You could always run a link wire to the cigar lighter or glove box light.
(Black wire).
It should then work as intended.

Just one wire down the 'A' pillar, and round behind the glove-box.

[dorsetdave]

Thanks Rob. I will have a go at feeding a new wire down the pillar.

[Robsey]

Try running a loose wire first, to check that my theory works.
It should.

But, if in the highly unlikely event that it doesn't work, then it would be a faulty light unit.

From how you describe the symptoms...
The light unit is working, and
I am confident that a new ignition live feed should solve your issue.

It is just strange that it has stopped working now.

Also - once you fit the new wire,
trim out and insulate the old defective wire at the light unit end, to avoid any shorting out.

From my understanding,
Both the cigar lighter and glove box take their feeds from Fuse 2 (20 amps).

So it looks like using either of those units to tap into, should be fine.

[dorsetdave]

Rob, Running a separate "ign" lead, after removing my link wire to the reading lights, feed allows them to work as per the handbook. The main interior light delay works as it should. All I have to do now is get a new wire down the A post.

Thanks for your help.

[Robsey]

My pleasure.

It is just strange how it had stopped for no apparent reason.

I suppose that is just Cavaliers for you.