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Re: Test Adapter

I need to test my idle and full throttle switchs.  Bentley says use a
test adpater VW1501 to connect two wiring harnesss'.  It then talks
about specifically grounding terminal 2 of the test adapter and checking
the voltage.  Test adapter VW1501 has three leads.

Is there a way I can replicate the functionality of this adapter or do a
similar test without buying the test adapter or am I left with no choice
but to buy said adapter

The Bentley test checks the full system with the computer in the circuit.
To test the switches only, you only need a multimeter.  Disconnect the
connector on the back of the engine.   Apply the meter across various pins
on the engine side of the connection.   I vaguely recall the center pin is
ground.  One edge pin is the WOT switch, the other is the idle switch.  In
any case, experiment should show which is which if they are working.  Just
measure the resistance across all pin combinations with the throttle in
closed, mid, and wide-open positions.  If not less than 4 ohms on the WOT,
or idle for the proper positions, the switch is bad.

Unlike some Audi models' switches, ours are essentially potted closed, so
they have to be replaced.  Sold only as a harness, they are expensive.  A
used one that tests good could be spliced in if you wish.  With extreme
care, (which I didn't achieve) one could drill into the WOT switch and
squirt some ProGold in, but whether it would cure a bad switch is only
conjecture so far as I know.

                .... Kirby   (Kirby A. Smith)
                              2 x 1988 90q
                          New Hampshire USA