Tach problems

depends on the ignition system you are running, if it is an MSD you will need the Tach adaptor. Take a look at the post started by "COZ" started 12-12-2001 under the headine "TACH NOT WORKING". Also do a search on this site under "TACH" & "MSD". There have been numerous discussions on this topic and you may find it helpful.

Good luck
Gary #06984

If it is NOT an MSD then your tach wire goes to the NEGATIVE side of the coil! Marlin.

Thanks Guys!

quote:

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Originally posted by JR:
Thanks Guys!

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The Ignition seems to be a Ford motorcraft type. Marlyn, I tried two wires to the negitive post. The first is a blue/black wire that comes out of the harnes right where all the electronics are. The other is a light blue wire that comes out of the harnes on the far side of the engine, where the water temp gauge wire comes out. Neither of these worked. the blue/black one would not let the engine run, and actually had it back fireing. Do I have the correct wires, or is there one I,m missing. JRM

The name is Marlin. The Blu/black wire is the tach feed and goes to the NEGATIVE side of the coil! The light blue is the 12 volts POSITIVE resister wire from the ignition switch and it goes to the POSITIVE side of the coil!! If you hooked the 12 volt positive up to the negative side of the coil and the tach feed, you may have just blown your tach out! You really need to get yourself a wireing diagram and know what your doing before you start connecting wires TOGETHER! Regards, Marlin.

Thanks Marlin, Sorry for the typepo.
I have the wireing diagram, and I see the blue/black wire on it. However, when I plugged it in to the negative side of the coil, the car could not stay running. It fired, then shut down, then backfired. That's when I tried the other light blue one. Neither seemed to work. I will pull the tach and chek it out. Thanks again

NO problem! If connecting the blu/blk wire to the coil negative side causes the engine to stall, backfire and stop; then something must be shorting out INSIDE of the tach, OR the wire (blu/blk) may be chaffing to ground (shorted) somewhere along the way. You might check this with a VOM, or continuity checker from THAT wire, (when disconnected, or connected ONLY to the tach), and to ground. All the best, Marlin. P.S.: There could also be the possibility that the coil is bad! You may try substituting another coil to test.

[This message has been edited by MARLIN JACK (edited 12-25-2002).]