I was working on getting my '70 TR6 actually inspectable (ok, after
a close call with the local constabulory over the weekend), and was trying
to debug the horn circuit. The DPO had hacked in a new horn and pushbutton
under the dash. This _might_ pass, but I'd rather not worry about arguing
(not to mention it's not very easy to use).
MUCH confusion resulted from the fact that the Haynes wiring diagrams
are poorly labelled, and don't include some of the variations used in the
US. For the life of me, I couldn't find the purple (hot) wires for the
old horns, and while I could find purple-yellow wires that looked right,
there weren't any purple-yellow wires on the diagram. Then I consulted the
Bentley manual, and found that in the '71-72 diagram there was both a
horn relay and purple-yellow wires for the horns. Aha! The relay was
there, and was toast (the copper oxide leaking out was an indication...).
I may just bypass the relay and ground through the horn switch - the earlier
AND later cars apparently did this. Time to call TRF.
My car was built in March 1970, but I guess they switched to a horn
relay earlier than known. Note that the car does have a hazard relay, which
was removed in the '71-72 cars. The hazards never worked, and I assumed it
was the flasher unit, and have had a new one on order for about 2 years from
TRF.
Oh, and to add to the fun, when I hit the hazard switch, the relay
sees all of .3V. Looking under the dash the power line for the hazards
may have been toasted - there's a wire in around the right area that burnt
it's way free of the harness. It's possible the switch is burnt too -
time to remove the tach, at least to run new wires to power and perhaps
to the relay... :-( The DPO had burnt a number of wires under the dash and
had made some annoying hacks (perhaps to get around some of those problems).
The car had 50 amp fuses in it when I got it (instead of 35 amp).
If it wasn't such a pain to do, I'd be REALLY tempted to get a new
wiring harness. Not to mention that I'm sure in some ways it wouldn't match
the actual configuration of my car (with horn relay and hazard relay, for
example).
--
Randell Jesup, Scala US R&D
Randell.Jesup@scala.com
Ex-Commodore-Amiga Engineer, class of '94
#include <std/disclaimer>
|