[Tigers] AutoMeter Cobra 8000 Tach installed

Smit, Theo Theo.Smit at dynastream.com
Sun May 16 21:03:39 MDT 2010


Grab an extra 12V battery (it can be pretty much anything including a cordless
drill battery in the range 12V-15.6V) and use that to power the tach. Make
sure that the tach ground is connected to both the negative terminal of the
'extra' battery as well as the chassis of the car. If your problem goes away
then it is the alternator, if it stays then it has to do with the signal
you're getting from the coil.

If the alternator has bad (worn) brushes then it can generate noise. A bent
shaft or shorted commutator on a generator can do bad things to tachs as
well.


If the problem is from the coil and the accel module, then try putting a
1N4003 diode in the line from the coil negative to the tach input. Try either
direction.

Hope this helps,
Theo

________________________________________
From: tigers-bounces at autox.team.net [tigers-bounces at autox.team.net] On Behalf
Of wsamouce [wsamouce at kc.rr.com]


Now a question for you all -

I am having a problem with the needle jumping around when the engine is at
idle.  Once the rpm is over 2000, it reads correct.  When I turn on the

-----------------------------------------------------------------------------
---
This e-mail and any attachments may contain confidential material for the sole
use of the intended recipient. If you are not the intended recipient, please
be aware that any disclosure, copying, distribution or use of this e-mail or
any attachment is prohibited. If you have received this e-mail in error,
please contact the sender and delete all copies.

Thank you for your cooperation.


More information about the Tigers mailing list