I'm sure everybody knew this but me, but just in case you didn't here's a
warning. When connecting an E-Meter RS-232 to any other device on the car
that is chassis grounded be sure that you use an isolator that is not the
B&B 9POP4 or any other supposed isolator with the following flaw. In this
case the negative side of 12 volt supply to the isolator is connected to pin
5 of the DB-9 connector on the computer side i.e. The E-Meter side since it
only takes data in one direction. The modem side is actually isolated but a
lot of good that does since it's the E-Meter that needs protection.

There is apparently a 100 ohm resistor in the E-Meter between pin 1 of the
main connector and pin 5 of the DB-9. This gets instantly fried as soon as
it's hooked up to a chassis grounded pin 5 of the DB-9 when power is
applied. If by chance it doesn't get instantly fried, it will when you start
to run the car because of the inductive current induced. After 2 fried
E-Meters, I won't be hooking up anything without checking the device against
chassis ground. The E-Meters still works and actually transmits most data
accurately to a laptop computer but the signal is too messed up, having no
ground of its own, to work with anything else.

Does anyone know where the resistor is that gets fried? I looked at the
board carefully with a magnifying visor and couldn't find a trace.

Rick Woodbury                                     Phone: (509) 624-0762
President, Commuter Cars Corporation          Toll-free: (800) 468-0944
Doubling the capacity of freeways                   Fax: (509) 624-1466
Quadrupling the capacity of parking            Cellular: (509) 979-1815
Zero to 60 in under 4 seconds
715 E. Sprague Ave., Suite 114             Email: [EMAIL PROTECTED]
Spokane, WA 99202                      Web: http://www.commutercars.com

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