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Tips

tach fix

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J

John Vudmaska

Freshman Member
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Hi Guys
Maybe you can help.I have a 1977 XJS
I don't think I have the right power amp. for
my car.
I would like to know if I can hook up the
tach from a nother place.
The power amp. has only 5 wires all my repair
manuals show 6.
the white and blue is missing how can I hook
up from another source
Any info would be apreciated.
Thanks John V
 
I'm going to print your question and show it to a friend who is a Master or Masters Jag mechanic. (I wish I could get him on here, but he doesn't really do computers)

Basil
 
Thanks Basil any help would be appreciated
I think this forum is the best for back yard
mech. like myself the support is tremendes
John V
 
The XJ style tachs use the output of the ignition amp to the negative side of the ignition coil for their sensor (RPM) signal. Try jumping the tach input wire (either blue and white or black and white) to the negative post of the ignition coil (black and white). If the tach gives you a correct signal then hardwire this connection and your tach is installed. Jack Farrington
 
The XJ style tachs use the output of the ignition amp to the negative side of the ignition coil for their sensor (RPM) signal. Try jumping the tach input wire (either blue and white or black and white) to the negative post of the ignition coil (black and white). If the tach gives you a correct signal then hardwire this connection and your tach is installed. Jack Farrington
 
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