Heater control illumination query ?

[bx petrol auto saloon]

Dear All,
Firstly, I am still having problems with just the two heater control 1.2w capless bulbs, that illuminate the heater controls.
Over these past few days I have managed to fit the circuit replacement circuit board ( thanks again to Stewart for the used ones )
However, the two bulbs don,t always illuminate, sometimes they won,t come on for about 15 secs. other times they don,t come on at all. I have tried wiggling the five pin spade connector terminal on top of the circuit board, to no avail. I have also tried wiggling the ignition key, to no avail.
I have even changed the replacement circuit board, with the other one that Stewart very very kindly sent me. To the same effect.
One thing I have noticed is that when both bulbs are not illuminating, the heater fan speed control is still working.
I have a hunch, that this problem is most probably down to the ignition switch contact box on the back of the ignition switch.
Another thing I was thinking it may be, if there is a inline relay fitted somewhere that is related to these bulbs. But I don,t that there is one, and that it is down to the ignition switch contact box.
Any kind info or advice would be very very gratefully recieved
Many thanks,
Vince,

[Defender110]

Earth leakage fault the other way round than normal?

This sounds like you have the earth leakage fault normally assosiated with the motor earth which breaks down somewhere in line and is fixed by linking it to the illumination earth next to it where the 5 pin plug fits. Perhaps by linking the 2 earths you will fix your illumination fault which normally fixes the motor fault? Have a look at the definative heater mod in the technical frequently asked q's section for further info.

[Tim Leech]

I take it the dash lights (speedo etc) are working normally?

[Way2go]

Another thing I was thinking it may be, if there is a inline relay fitted somewhere that is related to these bulbs. But I don,t that there is one, and that it is down to the ignition switch contact box.

Hi Vince, no relay but the dashboard illumination is fed via the Rheostat control under the steering column. The wiper contact on this maybe dirty with age and therefore causing the panel lights to be intermittent. (The lamps are independent of the fan control circuitry)

[Pogo]

Similar subject, is the green bit round the cigarette lighter supposed to light up?, and if so how is the best way to go about fixing it?

[Way2go]

Similar subject, is the green bit round the cigarette lighter supposed to light up?, and if so how is the best way to go about fixing it?

There is a bulb in the cigarette lighter that likely needs replacement. You need to remove the vent grill and part of the fascia to get at it in a Mk2. There is info in Haynes on tackling this in the blue book section 13*12. I did mine at the same time as the heater control lamps.

[bx petrol auto saloon]

Dear Kevan,
Firstly, thank-you so very very much indeed for your very kind reply Kevan
Secondly, I did go and have a quick shuffty at those wires on the connection block where the spade terminals are fitted. There ain,t alot of spare room in that bit is there
Vince,

[bx petrol auto saloon]

Dear Tim,
Thank-you too so very very much indeed for your very kind reply Tim
So sorry for my late reply, I had to wait until the sun went down a bit and then I still had to use a pillow over my head to get to see if the speedo illumnination was working correctly, which they are Tim I did look a bit stupid, but needs must sometimes
I most probably, haven,t even driven it in the dark yet
Vince,

[bx petrol auto saloon]

Dear W2G,
Firstly, thank-you too very much indeed, you are most kind
Secondly, " What a way 2 go " you are amazing and you hit the proverbial nail on the head I didn,t know that the heater control illumination bulbs where controlled through the dash rheostat It was as you so rightly said, a sticky part of the rheostat switch, I worked it up and down a few times, to clean itself up a bit.
Now, I have tested them for 40 times and they haven,t even blinked
Thank-you so very very much indeed, you are very clever indeed and are most kind
Vince,

[Pogo]

Way to go, thanks
Will have a look in morning