At 9:55 PM +1000 21/4/99, Andrew Miller wrote:
>Listers, (or should I direct this question directly to Dan Masters ?)
>Two questions wrt 1975 TR6
>1. I need a 'constant' live 12v connection to power the clock/tuning
>memory on the AM/FM Cassette. Which wire carries constant power easily
>accessible from the passenger side footwell on a LHD car ? (then again,
>since the steering wheel is off and the seats are out the drivers side is
>also easily accessible !)
>2. On the way home the other night I had to remind a minivan that there
>are other cars in other lanes. The stock horn sounds more like "ahem, I
>hate to interrupt but if it's not too much trouble would mind terribly if
>you checked your blind spot sometime during your lane change ?" so I bought
>a FIAM air horn set "Yo, check your blind spot BEFORE attempting lane
> My question: I would like to wire the FIAM compressor/horns in
>parallel to the existing set with a switch on the FIAM circuit. This way I
>could turn the FIAMs off and use the horn button on the wheel to sound an
>alert through the standard set (i.e. in my neighbourhood, polite reminders
>etc), if no response I could turn the FIAM circuit live and sound a second
>alert using the air horns (i.e. travelling on a highway with 18-wheeler
I have just done 1 and am in the process of doing 2.
1. You will find a purple wire leading to the light in the glovebox. Tap
into that for a constant 12V supply. You may find other purple wires and
these would also work.
2. I have installed a claxon horn (no wimpy air horns for me) behind the
grill. There is a change-over (also know as single pole double throw -
SPDT) relay near the horns to switch between the orignal horns and the
Disconnect the existing wires to the existing horns (disconnect both) and
connect one of those wires to the common terminal of the changeover relay
(terminal 30). Connect one side of the relay output (terminal 87) to the
original horns and the other side (terminal 87a) to the new horn. You will
also need a short wire to connect the two original horns together again.
To actuate the relay, you can switch 12V at the dash and take it down to
the relay coil, then earth/ground the other side of the coil (terminals 85
and 86). As I aready have 12V down near the relay for an electric fan, I
have chosen to switch the earth. Whichever is more convenient for you.
This is a fairly general description as I have assumed that you have some
wiring experience. If you need more detail then let me know. It is
easiest if you tackle the problem in two steps as per the two paras above.
It can be done and it is not hard.
A diagram of the relays can be found at:
Originally I intended to use the high/low beam switch to switch between the
horns, but this switch is live only when the headlights are on, so it
proved to be a little difficult as the changeover would not work with the
headlights off. Making it work would require major rewiring, so I will
settle for a separate switch.
74 TR6 CF29281U