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Re: Tach Problems

To: MG Nuts <>
Subject: Re: Tach Problems
From: Skye Poier <>
Date: Thu, 15 Aug 2002 11:06:57 -0700
I just had a thought, if the "good electrical shop" ran a wire to the
12v input from the LT side of the ignition (switched via the points)
then it would be getting on average, what, 8v with a 60deg dwell and
could account for low readings.

66 B

Word on the street is Charles & Peggy Robinson said:
>   The white wire loop is probably not at fault.  No one opened up the
> tach, did they?  A loose or bad connection there would make the engine
> run roughly.  The tach is an electronic unit with the loop as the
> trigger source.  As such, the tach needs to be connected to 12 volts and
> a good ground.  I have one of that type tach in front of me now.  There
> are four connections.  Two are bullet connections for the white wires. 
> Two are blade connections for 12 volts and ground.  The 12 volt
> connector is located on the PC board between the bullet connections. 
> That's probably where the electrical shop connected the new wire.  I'd
> get behind there and find the original wire in the harness and connect
> it back up, eliminate the extra wire and make sure the ground is
> connected correctly.  
>   I ran into this with an MG I bought on spec. One of the probs was that
> the tach didn't work.  The reason was as above.  In other word, BTDT. 
> YMMV but it's worth a look.
>   Cheers,
>    CR

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