> Rick Woodbury wrote:
> 
>> 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.
> 
>> 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.
> 
> Hi Rick,
> 
> I can't help with identifying the location of the fried resistor, but
> would point out that resistors tend to fry open, so since you already
> know which two points the resistor needs to be connected between, you
> ought to be able to make the meters reliable again by connecting a 100R
> resistor appropriately on the ~outside~ of the meter.
> 
> With a bit of care, it should be possible to solder one end of the
> resistor to the appropriate pin of the DB9 where it attaches to the PCB
> behind the terminal strip, and run the other lead (or a flexible wire
> attached to it) to pin 1 of the terminal strip.

Thanks Roger.

Actually when the first one started transmitting erroneous data I found that
pin 5 of the DB-9 on the E-Meter was not grounded. The manual clearly states
that it should be so I connected a jumper. The only reason I assumed that
there is a 100 ohm resistor is because when I got the replacement E-Meter
and checked to see if a new one was actually grounded I got a 100 ohm
resistance. After frying that one too, I then got another one and found 100
ohms again.

The one I jumpered without the resistor had some interesting
characteristics. When I had the jumper connected, the volts showed on the
E-Meter display correctly, however, the amps showed 600 mA at rest and
should have been about 100 mA. As soon as I ran the motors the display went
to over 1000 A, highly unlikely since the wheels were off the ground.

I'll try sticking a 100 Ohm in instead of the jumper and see if works then.
If the jumper is disconnected the whole E-Meter runs fine.

Thanks for your input.

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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