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-   -   Laser falsing, how to isolate the cause and solve (http://beltronicsradarforum.com/forums/showthread.php?t=1181)

BeltronicsPro March 8th, 2013 02:03 PM

Laser falsing, how to isolate the cause and solve
 
Issue: Some customers get a laser warning with rapid acceleration.
There are two known things that can cause this:
a) Noisy 12V DC line
b) Radiated signal from truck that is coupling onto the front/rear shifter wires.
c) In some cases we have seen that both 1 & 2 apply

Recommended Course of action:
The first step is to determine whether the issues is coming from a noisy DC line or whether a vehicle generated RF signal is being radiated onto the shifter wires.

Finding the source:
1) Isolate power from the vehicle - This can be done with a 12V gel cell. Please make sure that both POWER and GROUND have no connection to the vehicle and are only running off of the gel cell. Re-test with rapid acceleration.

2) If the unit no longer falses, then you know there is a significant source of noise of the 12v DC line. If the unit still falses, then go to step 3.

Things to try would be:
a) Re-route power AND ground to a quieter line (FM radio lines work well if accessible) - 12 volt accessory plug would be another common option.
b) Install the power filter*

3) Radiated coupling into shifter wire lines - This can almost always be solved be a re-route of the front and/or rear shifter wires. Some things to keep in mind:
First, note on the display whether the false is coming from the Front or Rear shifters:

Front Shifter Error - Keep shifter wires as far apart from any vehicle "modules" and pre-existing wiring as possible. If you have the wires running down the driver side of the engine compartment, move them to run along the passenger side instead. For testing purposes, lay the wires in the approximate final location and use a couple of tie wraps to secure temporarily. Use extreme caution to make sure that the wires are secure and cannot become tangled in any pulleys or belts.

Rear Shifter Error - Several vehicles have electronically "noisy" fuel pumps mounted in the tank. Running a shifter wire across the tank can be problematic. Run the wires down one side or another (as close to the edge of the vehicle as possible)

If you have been through all of the above steps and the issue still exists, keep in mind that there have been a few cases that have required a better power and ground location, a power filter* and rerouting of the shifter wires to finish the install. If all steps fail, the shifters will need to be sent in for inspection.

* the power filter (aka RF Filter) mentioned above is available by calling us at the number in my signature below, it's price is $35.00 including shipping to the continental US.


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