The Rain Tracker as well as the rest of the wiper system) works better with good wiper blades.
Extremely worn wiper blades will cause the system to over-wipe. In such cases, replace the blades.
On vehicles that wipe from the center out e.g. recent Chrysler vans) having the sensor too close to the
edge of the wipe pattern will make the system wipe too much. Center-out wipers are more prone to the
wipers making more follow-up wipes; it is more important to keep the blades clean.
The sensor will be fooled by vibration; if you tap on the sensor, it will run the wipers. Don’t tap on the
sensor. False wipes due to vibration / road bumps are almost always caused by an unsecured sensor
cable. Use a black cable tie to secure the sensor cable to the mirror mount.
If the vehicle engine is not running, the wipers can run so slowly as to cause the wiper blades to fool the
sensor. Try the test with the engine running.
Follow up wiping can be excessive under conditions just about the freezing. These conditions are rare,
and the Rain Tracker still should not cause smearing.
Wipers never completely
stop wiping-- very long
intermittent
If the wipers never completely stop, replace the wiper blades they were due for it, weren't they?). Clean
the area just over the Rain Tracker sensor, and polish the glass with a soft cloth.
Check each of the conditions listed above.
Rain Tracker does not
respond fast enough
Note that it is normal for the wipers to speed up and slow down over several seconds. Real rain storms
do not start or stop instantly. The Rain Tracker should respond appropriately to a real rain storm. With a
spray bottle demonstration, it will appear to respond too slowly.
Sensitivity too low Rain-X or car waxes can makes the sensor too insensitive. You can use Rain-X or any other hydrophobic
coating, but clean the area just over the Rain Tracker sensor, and polish the glass with a soft cloth.
Be sure the Rain Tracker coupler installation is reasonably free of air bubbles. No more than a few,
each a few mm in diameter. If you use our supplied anhydrous alcohol pad to install, you will get a
permanent, high-quality bond.)
If the sensitivity is not to the driver's liking, you may shift it up or down using DIP switch positions 1, 2,
and 3. See the user manual for the proper settings.
Sensor appears to
actually slow down with
more water
This can happen in installations with external resistors. Check to make sure that the external component
values are correct. This condition can be tricky to diagnose because it looks like a sensor problem. Use
an ohmmeter if possible.
Sensitivity too high If the sensitivity is not to the driver's liking, you may shift it up or down using DIP switch positions 1, 2,
and 3. See the user manual for the proper settings. Note that the Sensitivity code from the LED will not
change with DIP switch settings.
On vehicles that wipe from the center out e.g. recent Chrysler vans) having the sensor too close to the
edge of the wipe pattern will make the system wipe too much.
Could you have wired the activation switch to ground instead of to B+? If you makes this mistake, it
will put the system on in maximum, not default, sensitivity, and give LED code 1-9 or 2-9.
No amount of water will
make the system run fast
This model of Rain Tracker does not automatically make the wipers run fast.
Responds to water, but
Fast speed is slower than
it should be
There is probably some wiring error that is shorting the wiper motor slow and fast windings together.
For example, if the power diode YEL & WHT) from Rain Tracker not wired in place. Be sure to correct
this, as it wears the wiper motor out.
Wipers wipe for no
reason
False wipes should be rare. Sometimes the Rain Tracker will see the first droplets of water before the
driver notices.
On very hot, humid days, water can drip down from the air conditioning units of the vehicles ahead.
This can cause enough tiny drops to trigger the Rain Tracker. Also, there can simply be tiny droplets of
water in the air in extreme humidity—the Rain Tracker detects water droplets as small as about two one-
hundredths of an inch. Simply turn the Rain Tracker off under such conditions.
Wipers wiper when I
drive over bumps
Check to be sure that the sensor is securely snapped into the Rain Tracker coupler.
Rain Tracker RT-40A Troubleshooting Procedure : External Component Applications
www.raintracker.com Page 3 of 4 Last Revised: 08/01/08
