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1970 MGB GT Interior Light.

Posted: Sun Aug 20, 2017 8:01 pm
by Paul Harris
Trying to sort the mucked about wiring out ! Would I be correct in thinking that the "courtesy" switches in the doors only operate the light fitted in the tailgate area ? The map reading light seems to operate correctly from its pull switch, so I assume this is nothing to do with the courtesy light switches ?
Manual not much help !
Many thanks.
Paul.

Re: 1970 MGB GT Interior Light.

Posted: Mon Aug 21, 2017 10:19 am
by Ian F
Hi Paul,
on my 1972 BGT (which may be different to your 1970 model?) the door switches operate the courtesy light on the radio console unit below the dash. I hesitate to call it a map reading light because I've never found it much use for that function - I have a plug-in map light which goes into the cigar lighter socket. The tailgate switch operates the light above the loading area - separate from the other interior light circuit.
Hope this helps,

Ian F.

Re: 1970 MGB GT Interior Light.

Posted: Mon Aug 21, 2017 12:51 pm
by Vic Butler
Afternoon Paul.
Had a look at the official workshop manual wiring diagram. Not much help. Shows courtesy/map reading light switch and courtesy/map reading light (items 101 & 102 respectively) My 1977 BGT interior lights operate the same way as Ian' s.
Not much help I'm afraid.
. Vic Butler.

Re: 1970 MGB GT Interior Light.

Posted: Mon Aug 21, 2017 2:57 pm
by Michael Barclay
Hi Paul
I had a look at the wiring diagrams for both 1970-1971 and 71-72 year cars and can see courtesy light /map light (item 101/102 on the radio console is operated by the front door switch items 21 and 22. The luggage compartment lamp is operate by a separate switch operated by the tailgate .Theses are items 65 and 66 respectively on the drawing . If it helps the wiring colour is PW (purple and white) for both circuits. attached part of the Schematic showing the interior lights. Sorry about the quality, but hope it helps
Mike Barclay

Re: 1970 MGB GT Interior Light.

Posted: Tue Aug 22, 2017 4:58 pm
by David M B Leggeat
Paul,
My 1968 CGT interior lights operate as you describe with the door switches operating the light above the luggage area and the map light at the LHS of the dash operated by a push / pull switch.

According to Clausager a change was made from late 1970 for the 1971 model year BGT whereby the door switches also operated the map light and a separate switch was operated by the tail gate for the rear light.
Regards,
David.

Ref: Clausager A. D. , 'Original MGB' .

Re: 1970 MGB GT Interior Light.

Posted: Tue Aug 22, 2017 8:18 pm
by Paul Harris
Many thanks for your help everyone !

Matters a bit clearer now...as my car never had a centre console light (just the "pull switch" map light) then the door switches must be for this light at the back above the tailgate.

There had been some fault in the wiring and a previous owner had it all disconnected which doesn't help matters.

Thanks again.

Paul.

Re: 1970 MGB GT Interior Light.

Posted: Wed Aug 23, 2017 2:06 pm
by Michael Barclay
Hi Guys
According to my schematics the change to the way the switches /lights work was made from Chassis no GHD5 219002. (GT Cars)
Hope this helps.
Mike Barclay

Re: 1970 MGB GT Interior Light.

Posted: Wed Aug 23, 2017 7:54 pm
by Paul Harris
Hello again,

Yes Michael, that helps very much. My car is Chassis GHD5 189755G, so that would certainly have been wired on the old system.

I know I have the two door switches, but I can't get at the tailgate to open it at present (don't ask !)...over-running front suspension job .

Seems then, assuming I have a tailgate switch, this together with the door switches all operate the single interior light at the back.
Apparently disconnected years ago due to blowing fuses when in use....wonder why ? It would seem to be a very simple layout with not much to go wrong. Famous last words !

Thanks again chaps.

Paul.