Karl,

The wiring isn't much.  The only real difference between the $138 model
and the $40 universal is the plug and the length of wire.  All you have
to do is snip the wires of your existing one near the sensor and snip
the plug off the universal.  Splice the wires together and voile, you
have the $138 model.  I've got more detailed instructions if you need
them, but, believe me, it's one of the easiest things to do on the
vanagon!

Tonya
87 Vanagon GL Wolfs
74 S. Beetle