all.
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"
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.
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.
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.
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.
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.
The sensitivity detects darkness and increases the sensitivity a little at night.
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 adjust it. See the installation manual.
Sensor appears to
actually slow down with
more water
This can happen in installations with external resistors. (Usually not HSS or GSS applications!)
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 to check the value of the
external resistors.
Sensitivity too high
If the sensitivity is not to the driver's liking, you may shift it up or down using the procedure
shown in the installation manual.
The sensitivity detects darkness and increases the sensitivity a little at night.
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.
Rain Tracker RT-40A Troubleshooting Procedure : Motor Switching Applications
Page 3 of 4
Last Revised: 08/01/08
