In a message dated 98-10-08 19:38:18 EDT, JONES_M2@popmail.firn.edu writes:
> Please help me with this one. All TR6 wiring diagrams show a single
> wire leading to the positive terminal of the coil. On my 74 it is coded
> white with yellow. On earlier models it may be of a different colour.
> However on at least the 73 and 74's there is also a red wire with a
> cloth cover. It doesn't show up in any of the wiring diagrams. In the
> standard Lucas colour coding the red wires are lights. What is this
> thing and what does it do? If it is the resister wire the wiring
> diagram is wrong.
Bob,
Color codes are pretty good when they are new. Over time, though, the colors
can change. The wire you describe is indeed the ballast resistor. It's color
is supposed to be pink and white, and is shown as item #48 on your wiring
diagrams. This wire supplies about 8 volts to the coil when the engine is
running. When the engine is being cranked, the starter relay - item #50 -
bypasses this wire, applying the full 12 volts to the coil.
For a little more on this subject, see:
http://www.vtr.org/maintain/ballast.html
Triumph wiring diagrams give a "fairly" good representation of the actual
physical wiring layout, but they can't be counted on for too much detail. The
wiring diagram shows the connection of the pink/white wire to the white/yellow
wire a good distance from the coil itself. This is a perfect electrical
representation, but not a very good physical representation.
Dan Masters,
Alcoa, TN
'71 TR6---------3000mile/year driver, fully restored
'71 TR6---------undergoing full restoration and Ford 5.0 V8 insertion - see:
http://www.sky.net/~boballen/mg/Masters/index.html
'74 MGBGT---3000mile/year driver, original condition - slated for a V8 soon
'68 MGBGT---organ donor for the '74
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