I can hear a relay click in
the interface module, but
the wipers do not run.
●
Check the wiring around the SLOW relay—the BLU and the GRN wires from the Rain Tracker,
and the components connected to them. Are they going to ground or +12V, as the drawing calls
for?
●
Check the
external component values
. Resistors are not polarized and can go in the circuit in
either direction. By the far the most common problem installers have with this sort of wiper
system is using the wrong component values. Resistor color bands are tiny and hard to see.
Check them (in circuit, ideally) with a multi-meter.
●
Diodes are polarized and must have the colored band in the direction shown on the drawing.
●
Check that you have identified the right wires to Tee into. This is especially important if there
are two of the same color wires in the vehicle. (For example, two dark green wires coming
from the wiper switch assembly, as is the case in many GM’s.) You can check this with a
voltmeter:
●
Unplug the Rain Tracker from 10 position connector connected to the vehicle.
●
Connect the black voltmeter minus probe to the black ground wire at the Rain Tracker
connector. (Pin 1)
●
Place the voltmeter positive at the Rain Tracker connection that connects to a resistor.
●
With the vehicle on, change the wiper switch settings. Verify that the voltage changes
when you change the switch. If it does not, you probably have the wrong wire. This
test also makes sure you have a good connection to the resistor.
●
If the Rain Tracker installation calls for more than one resistor, make this test for each
of them.
Wipers pulse, but at
FAST instead of SLOW
speed
Check the component values—did you use the right one for each location?
Wash comes on for no
reason
Some Ford systems default to this when a wrong resistor value is applied. Check the resistance values.
4. Diagnosing Sensor problems.
•
If you skipped straight to this step, go back and systematically go through the procedure from the beginning, eliminating more
common problems.
•
The sensor adjusts itself to the windshield when it powers up. To be sure that it has done this, turn the ignition off and then on.
•
Place the existing wiper switch in manual off, and activate the Rain Tracker system
•
See how the system responds to a spray bottle or garden hose.
Symptom
Check
System does not respond
to water at all.
Did you mount the sensor so that the double-stick tape wets out against the glass?
•
The sensor will not see through the red release-liner tape—you must remove it.
•
You cannot just tape the sensor against the glass without mounting it.
•
The tape must be fully ‘wetted out’ (appears black from outside the vehicle)—you cannot lightly
tack the sensor to the glass.
Wipers wipe every five
seconds, regardless of
rain
This is what the system does when the sensor is disconnected. So, check that the sensor cable was not
cut during installation.
Also, the cause could be one of the “Wipers Keep Wiping” issues below.
Sensor responds barely at
all.
Is the sensor mounted too far in the shade band? From the mid 90's on, most US vehicles come with
infrared-absorbing shade bands. The Rain Tracker sensor can be mounted on the edge, but not deeply
within, the shade band.
Is the windshield an infrared reflective type? These are rare! On some Chevy venture vans, 1995-2001.
You can see the yellowish coating ending near the edge of the windshield, and usually built-in antennas.
The windshield logo may read "Sun Gate"
Is the windshield more than 0.25" (6 mm) thick? These are used on some large RV's with single-piece
windshields. (Not on any passenger cars, vans or light trucks.)
Wipers keep wiping
without water
A few follow-up wipes are normal. These are to clear water that might have blown off the hood but
might have missed the sensor.
Rain Tracker RT-40A Troubleshooting Procedure : External Component Applications
Page 2 of 4
Last Revised: 08/01/08