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Sun Tach. Wiring Help

11364 Views 4 Replies 3 Participants Last post by  docvette
Greetings All,
My father just gave me his sun tach. (chrome tear drop case style) for my 73 vette. He purchased it new in 1958 or 60, can't remember. Anyway it has some history, etc.

I am trying to install, but am confused. the tach has one brown wire coming out of it, that is it.

I am thinking that it may have connected to the coil neg. terminal.

I have a msd 6al box & matching distributor. I purchased the msd tach. adaptor box. The wiring diagram shows tach. with a hot wire , coil wire and a ground wire.

Help, I would really like to run this tach.

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Doc here:pimp:

If It's an electronic Tach, it should have at least 4 wires coming out of it.

Should be something in the order of:
  • RED =12 volts

If you only have one wire coming out, sounds like someone has cut them off inside the tach, You might have to remove the back and track those wires down, and If your careful and handy with a slobber gun..solder some new wires on the tach...

Are you putting this on a VETTE? If so, don't forget To Install the Tach Lead on the TACH filter (on the right rear of the intake manifold) on the Stock Tach side of the filter, not the HEI side, Else, your Tach could be damaged, OR be grossly in error.

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I have a MSD setup also. The wire that would go to the dist. or coil on a regular system will go to the tach terminal on the 6al box. If you have the MSD instructions you will see it stated there.


Doc Here:pimp:

OK, just wanted to be sure you weren't hooking it up to a Stock Vette system...So many times the Tach gets blown out or reports errors when the Tach filters are bypassed...

They don't exactly Make the filters public info either...until you lose a tach, or the filter goes out..$50 bucks for a Day~um Electrolytic Cap!!

You Should be fine with the MSD Setup.

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Try opening it up and looking for the other 3 wires..

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