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Early Plus 2 missing light relay

PostPosted: Tue Dec 24, 2019 6:21 pm
by bill griffiths
I became attached for many years to the idiosyncratic headlight operation of my first Plus 2.
But I have now found towards the end of the rebuild of the new car that I am missing a relay and the wiring diagram gives no help in finding a replacement.
The relay is between the light switch and the column switch.
It gets power from a blue wire from the light switch.
It sends power to the column switch via a brown/blue wire. (Frankly, I think a bad choice of colour!)
It also sends a brown/purple wire to one of the limit switches operated when the LH headlight closes,
and there is a mysterious blue and black wire which seems to turn up at C2 on the headlamp relay under the bonnet!
If I knew what happens inside it I could no doubt easily replace it. Any help would be appreciated. And Happy Christmas to to all. Regards, Bill

Re: Early Plus 2 missing light relay

PostPosted: Wed Dec 25, 2019 7:03 pm
by wotsisname
hi Bill is this an early +2? is the one you are after abehind the dash or at the front end.. I think the one behind the dash is a 6RA.. I can check in a day or two. It took a while , but I eventually figured out the logic of the iring diagram

Re: Early Plus 2 missing light relay

PostPosted: Wed Dec 25, 2019 8:53 pm
by bill griffiths
Thanks!
I had a productive Christmas Day (in between eating!) and worked it out.
The missing relay is behind the dash and is simply to provide for the cut out when the LHS pod is retracted.
I had in my spares a suitable relay and after adjusting the ?micro? switches it was done.
Current to the column switch is available only when the relay is closed by the brown/purple wire from the micro switch grounding the solenoid.
Another problem not adequately illustrated is the blue/black wire to the flashing relay which comes from the lamp switch. For those not starting with an assembled car, this is live only when the switch is off! It thus provides in that condition for flashing headlights when raised.
There appears on the wiring diagram a ?UB?
link on the ?HEAD RELAY? which colours can only have been chosen to confuse? The link simply provides positive power from the lamp switch to the solenoid.
Regards
Bill

Re: Early Plus 2 missing light relay

PostPosted: Wed Dec 25, 2019 11:14 pm
by bill griffiths
A small revision is needed!
I have checked my collection of lamp switches.
Their dates vary between '67 and '69 and they all bear the number 31788D.
None of them has provision for a live feed only in the off position. This means that the headlights will flash
in the circumstances I described if the pods are raised when the lamp switch is in the off position, or in
the park light position.
The connections are numbered, although the numbers do not appear in the wiring diagram.
The connections which work (There may be alternatives!) are:

1 Feed from ignition switch brown/blue. Note: 1 is uppermost when the switch is installed.
3 Park and feed to panel switch. double red.
6 Feed to flasher relay middle post. blue/black. Note: only live when lamp switch is off or at park.
8 Feed to headlight relay behind dash. blue.
Regards,
Bill