Tip & How-To about Car Audio & Video
On my Veypor VR2, it developed a problem where the speed reading would not indicate as it normally did. At first I thought it was sensor at the wheel not picking up the magnet as it rolled past, but as it turned out the problem was in the VR2 unit.
To check if you may be having the same problem as I did, plug in the AC power adapter, and with a DMM, measure the voltage between the two pins at the upper left corner; (looking at the back with the connector at the bottom).
The left pin is ground, and the second pin is the speed sensor input pin.
The voltage should be 5V. If you take a wire and touch it between the two pins, you should see a reading on the speedometer. If you do, then the unit is probably okay, and you'll have to look at the Hall effect speed sensor.
In my case there's a transistor in the unit used to switch the speed signal that started going bad, and the current leakage pulled down the voltage.
After replacing it with another PNP resistor, the voltage at the speed sensor input pin went back up to 5V, and it worked normally again.
Posted by Dusty Ryan on
Nov 04, 2011 | 2008 Lexus SC 430
Oct 28, 2009 | 2005 Chevrolet Colorado
Aug 10, 2009 | 2002 Toyota Sienna
May 07, 2009 | 2000 Ford Expedition
Mar 03, 2009 | 2003 Ford Explorer
535 people viewed this tip
Usually answered in minutes!