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
Common Sensor
Problem
One of the most common calls we get for tech support is for sensor coupler issues.
When you install the coupler on the windshield, be sure to follow instructions closely. You may
think you did it perfectly, but problems still arise.
Be sure there are no bubbles or other obstructions in the sensor tape. The problems can be two
fold: it can can cause false trips or inhibit what the sensor “sees”. Depending on the location of
the bubble, it may or may not cause a problem.
Also, small bubbles that did not cause a problem initially may now cause problems. This is
because, over time, heat from the sun may cause the bubbles to get bigger.
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, and actually
install the sensor using the procedure in the installation manual.
•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.
•Verify that there is 12V getting to the sensor. Check by unplugging the sensor, putting two
wires (resistor leads are a good choice) into the sensor cable, and check with a multi-meter.
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 very 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 ate"
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 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.
Rain Tracker RT-50A Troubleshooting Procedure: Motor-switching Applications
www.raintracker.com Page 4 of 6 Last Revised: 08/02/12
