[TR] TR6 Meltdown

Randall TR3driver at ca.rr.com
Tue Dec 13 10:26:33 MST 2011


> the insulation on the harness 
> is burned/melted
> from the alternator back through the firewall

Stock alternator?

> Did I just have a over charge condition....? What happened? 

Could be; or you could have a shorted cell in the battery.  But the harness
wiring should be able to take all that the alternator can produce, even with
a shorted regulator. So there may have also been a high resistance
connection somewhere.  With those kind of currents, it doesn't take much to
get hot, then the heat corrodes the copper and the resistance goes up, which
produces more heat ... you get the idea.  A short inside the alternator is
another possibility, but wouldn't explain why it stopped when you turned off
the key (unless it was just coincidence).

> from the alternator back through the firewall, under the dash 
> and back out and
> up to the positive terminal on the battery. 

Must be an early TR6 then.  I believe the later ones used a more direct
route.

> What is the best
> fix in terms up update opportunity and cost?

Lowest cost would be to assess the damage to the harness, and replace only
the burned or shorted wires with new wires run outside the harness.  Not
very attractive, but can be quite effective.  I patched up my TR3A harness
after a similar incident, so long ago that I had forgotten all about it
until I pulled the harness from the wreck.

Otherwise, you'll need to replace the harness, either with a reproduction of
the original or one of the excellent upgrade harnesses from Advance Auto
Wire.

> Why didn't I blow a fuse? 

That's easy, there are no fuses that protect the charging circuit.  Or the
headlights or ignition, for that matter.  Only about half of the wiring is
actually protected.

-- Randall  


More information about the Triumphs mailing list