At 09:06 PM 2/17/2013, neil n wrote:
>My understanding is that if using the OEM back up light switch to
>control additional back up lights, it's best to use a relay to carry
>the added load. Originally I was going to do this but then chose to

Very wise.  On the manual transmissions I'd certainly consider adding
a relay just to power the stock lights, since the switch eventually
gets pitted contacts and fails.

There are two styles of switch for the M/T with different terminals,
different construction internally and I believe different shimming
requirements when installing in the transmission.  The later style
with IIRC an integrated plug instead of individual spade terminals,
is of considerably lighter internal construction.

A/T backup light switch is integrated with the starter lockout in the
shifter quadrant and is of heavy and accessible construction.  You
can clean and to some extent adjust it, and keep it running a long
time before having to spring for the expensive lockout/reverse switch assembly.

Yrs,
d