dei 507m problem

Hi,

I Just bought and carefully installed a new DEI 507M in my 1990 GSX Eclipse.  The detector is located label-up and parallel to the floor pan.  The general problem is that it doesn't trigger when I jack a front tire clear of the floor. Both wire loops (white and black) are in the default position.

Test conditions: Red wire with 1A fuse connected to always-on +12V. Orange wire connected to "Ground When Armed" (measures 11.3V disarmed, ~0.08V armed). Blue wire connected via a 2.2K resistor to always-on +12V for purpose of testing.

Test: With the car fully down, I measure the voltage across the blue wire resistor as 0.0V -- no trigger current present.  I initiate the arm sequence and when it completes, the Orange wire goes to ~0.08V and the Blue wire resistor voltage goes to 6V (2.7mA draw). I jackup the passenger side front until the tire clears the floor.  The Orange wire is still at ~0.08V (as it should be), and the voltage across the Blue wire resistor remains 6V.

I see two specific problems:  One is the Blue wire doesn't wait for a trigger condition before it starts pulling on the alarm sense wire.  The other is there is no apparent change in detector state when a wheel is raised off the floor.  FWIW -- the quiescent current draw of the detector (Red wire to armed Orange wire,  Blue wire disconnected) is 1mA.

Am I doing something wrong? Or have I just been lucky enough to purchase a brand new defective 507M?

Thanks -- Trevor

PS.  I just made some measurements of the Blue wire voltage referenced to chassis ground.  When armed with a 2.2K resistor to +12V (as above), the Blue wire measures 6.18V.  When disconnected and disarmed (Orange wire not grounded), the Blue wire measures 10.73V. When disconnected and armed, the Blue wire measures ~0.08V. 

PPS. Guess I should also mention the target trigger sense is the hood-open input on the OE ETAC security controller.  Open hood is detected by pin switch grounding of the sense wire -- Blue/Black at connector C-16-2 pin22 of the ETAC.  My purpose is to mate the 507M blue wire to that sense wire and was expecting a simple open collector direct connection would do the job, but it didn't work, and that's how I came to be making these measurements and asking for input.

your ground when armed should bea constant ground and your meter will show 12v when activated.

if you have an existing alarm, connect the wires to the shock sensor, but diode isolate all wires.

Hi!

The "Ground When Armed" is a constant ground as long as the alarm is armed, otherwise it follows whatever is tied to it.  If you mean a voltage measurement from the red to the orange wire while armed should be the battery voltage, yes, it is.

According to the observed current/voltage behavior of the blue wire, it's open collector and is pulling on the sense wire at all times the system is armed.  Given open collector, inserting a diode isn't necessary, though I realize that's the standard practice.  The red and orange wires should never require diodes.

Great :(!  I bought it specifically because I was told it actually works well.  Maybe it's another of those sample specific situations.  The Eclipse ETAC ignores it anyway with direct connection to the hood-open sense wire (normally rides at about 0V when armed).  It responds to hard short to ground, but the 507M's Blue wire shows no sign of cutting it.  If I can get the darned thing to display a coherent before/after trigger behavior, I can throw together a relay interface for a genuine ground -- but first things first.

Too bad Directed doesn't provide electrical specs, not even for the trigger wire.  I'd have thought that would be automatically included with electronic apparatus -- couldn't find it online either.

Still waiting for return instructions from the Ebay seller.

I ordered a DEI 506T Glass-Break sensor at the same time as the 507M Tilt sensor (different vendor) and it just arrived today (slow as molasses shipping :().

I reused the "Ground With Arm" on the Black ground wire (no point in having it active all the time), connected the Red wire to always-on +12V, and my trusty 2.2K resistor between the Blue Wire and always-on +12V (just as with the Tilt sensor).  I then set it for max microphone sensitivity and gave it a whirl.  At arm, the resistor voltage briefly jumps to full BAT voltage (understandable power-up transient), and then returns to zero.  I clunked a set of keys against the driver door window (microphone sitting on the dash) and the Blue wire resistor voltage again jumped to BAT, and then back to 0V.

I then tried connecting the Blue wire directly to the ETAC Hood-Open sense wire (no resistor or diode).  I repeated the test and as soon as I clunked the keys against the driver window, the alarm fired :)!  Superb -- too bad the 507M Tilt didn't behave as nicely.  Since I doubt the Tilt trigger output is intended to be significantly different from the 506T, I would expect a "good" Tilt sensor should drop in just as cleanly and without any additional interface "glue".

I'll go ahead and complete the 506T install and cross my fingers for the replacement 507M.  The defective original will be off to the vendor in Thursday's mail.

The combination of a test resistor for current measurement plus voltmeter allow me to see what the sensor trigger output is doing.  Since DEI doesn't specify the behavior and I've already had trouble with one, I prefer to test first instead of simply trusting it to work with my OE security controllers.  If I can get the 507M working properly with my Eclipse ETAC, the next step will be installing one with my 2008 xB controller.  I find it helpful to understand the interface behavior.

Received the replacement 507M today, tested its behavior, and now it's installed.  I raised the front corner far enough to trigger it and the tire was still in contact with the ground (default 1 degree sensitivity) -- looks good.  Guess I'll just have to see how it behaves over time -- hopefully, no false trigger problem.

Thanks for the help folks :)!