7 replies to this topic

[bluequinn]

The interior light on my 1991 Mini Special (basically a left hand drive City with opening rear windows) doesn't work at all.

I assumed it was the fuse with the hazards but now I have fixed that and have working hazards I still don't have a working interior light. 

Doesn't matter which switch position. Bulb looks OK. It's this type of light http://www.minispare...y/AFU4092.aspx 

 

What other things may cause this?

[Quinlan minor]

 Bulb looks OK.

 

What other things may cause this?

 

A bulb that looks OK but isn't.

Check the bulb with the battery, If it lights, check the bulb holder with a volt meter.
 

[stuart bowes]

Just to confirm have you tested with the switch as well as just by opening the doors (and have you checked both doors)

Just to eliminate the door switch which could just have some crud in it and not connecting to earth properly

Or a disconnected wire to the above (purple and white IIRC)

Edited by stuart bowes, 13 May 2023 - 06:50 PM.

[stuart bowes]

Sorry just re read doesn't matter what switch position. Ignore my suggestion

[bluequinn]

I replaced the bulb on my interior light today, and it still didn't work.

So I removed the fitting and cleaned up all the connectors until they were shiny.

Upon refitting the bulb worked. Yay!

For about 5 seconds. Boo!

 

When I removed it, the inside of the bulb was covered in a white deposit. Bad things had happened. 

I tested the voltage with my multimeter and unless I was doing it wrong (entirely possible) it looked like there were 26 volts going to the light!

I am very puzzled.

[bpirie1000]

26volts... no wonder the bulb burst....


Seams like a new setting is needed on the volt meter....battery only has 12v...

[stuart bowes]

You sure you're not reading amps by mistake

That's the only thing I can think of that might get you to 26

Unless I recall incorrectly (?) The light is fed by permanent live so taking a reading there is effectively the same as a direct reading off the battery (ignoring negligeable voltage drop over relatively short cable lengths)

Edited by stuart bowes, 14 August 2023 - 12:52 PM.

[bluequinn]

OK, turns out it was 0.26. My battery was flat as a pancake.

 

I figured this out, (and also probably why my battery was flat)

The original bulb was OK, but the wiring in the switch unit was wrong.

 

The post '85 interior light, with the Austin-Rover logo in the perspex, should be wired so that the purple/orange wire is on the terminal that connects to the bulb body, and the black earth, and purple/white door wire should be on each side of the switch, which connects to the bulb positive. Mine had the earth where live should be, and the other two wires on the switch.

 

You'd think this was right if you had seen the layout of the diagram in the 1992 repair manual but not paid proper attention to it. It's much clearer in the 1997 electrical manual.

 

All working now!

Edited by bluequinn, 15 August 2023 - 05:04 PM.