Control Pressure Actuator testing help - please!

[SJ]

Check your ammeter first. Make sure its working. Most amatuers will blow out
the internal fuses and or resistors in meters when checking amperage.

This is a simple test to make sure your ammeter is working correctly at the
scale that you will be using.

10 ma = .01 amp
amp = volts/resistance
.01 amp = 12v/Resistance
Resistance= 12v/.01amp
Resistance=1200 ohms

Watts = RII = 1200 X .01 X.01 = .12 watts

Go to Radio Shack, buy a 1200 ohm, 1/4(.250 watt) resistor. Get some test
leads also . . .wires with alligator clips on ends.

Using your car battery, attach circuit as follows:  Make sure your ammeter
is set to high scale 250 ma.

battery+<--->1200 resistor<---->+ammeter-<---->battery-

The ammeter will read .01 amps, or 10 milliamps. You can set the range scale
to smaller value to read more accurately. Check all the ammeter ranges to
make sure they all work. You may find that one or two ranges will not work
because you cooked out a resistor.
Some ammeters will only read high currents. The lowest scale may be 1 amp.
You wont even see the needle deflect if you are trying to read .01 amp on a
1.0 amp scale!

If the above test does not work, open up the ammeter and check the internal
ammeter fuse. Most likely its blown. Get a replacement from Radio Shack.

SJ
85 Dodge PU, D-250, 318, auto
85 4k - - sold but still on the road
88 5kq
90 100q

> Message: 13
> From: CTDiesel at aol.com
> Date: Sun, 9 Mar 2003 20:05:36 EST
> Subject: Control Pressure Actuator testing help - please!
> To: quattro at audifans.com
>
> For those of you who have seen my postings in the past, if i can ask for
your
> help with this continuing saga.  It seems so simple but it just doesnt
work
> for me.
>
> I made my own wiring harness for testing mA to the control pressure
actuator
> aka diff pressure regulator.  I had no luck in being able to read mA on 4
> different mulitmeter testers.  So then i broke down and bought the factory
> harness thinking maybe mine was bad.  But still i cant get a mA reading
with
> all my testers.  Using the test lead ends of the new harness when you
touch
> them together the engine idle picks back up so i dont think the juice is
> flowing through the meter and to/from the ECU.
>
> I know the cpr is working because when you unplug the connector the engine
> labors (chugs).  Then plug it back in and it idles back up.
>
> Am i missing something in trying to get this to work... I know this is my
> problem as all vacuum leaks are fixed and all sensors are new.
>
> Please help this confused mind,
>
> DJ