Aftermarket Tachometer Hookup Question

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Dec 21, 2008 | 02:08 PM

burninrubber2416

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Aftermarket Tachometer Hookup Question

For christmas I got a aftermarket tach from my dad. I got the power, ground and illumination wires all hooked up. I know your supposed to hook it up to the negative part of your coil, question is, where is it at on a 1987 F150 with a 4.9L I6? Lol. I looked through wiring diagrams and looked it up on the All Data DIY program, but I couldnt find any negative/ground for the coil. So where can I put the green wire at to get it to read RPMs? Whereabout under the hood, and what color(s) should the wire be? I did a search for the topic, but came up with no answers to where it would be. I seen someone say something about a Tach Testing wire or something of the such. Any help would be appreciated. Thanks guys.

Dec 21, 2008 | 03:32 PM

DJdemon6696

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isnt it the positive from the coil?? nway its on the coil.. on the passenger side of the engine of the 4.9 chek wich one works.. there are 2 wires goes to the coil.. connect it tot he red if it doesnt work connect it to the other one it wont damage the tach atleast it didnt damage mine.

Dec 21, 2008 | 05:25 PM

JB88BII

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You connect the signal wire from the tach to the GREEN wire on your ignition coil, which is the negative side djdenon is right there are only two wires going to the coil but the green one is the one you need to get the signal from.

Dec 21, 2008 | 05:51 PM

burninrubber2416

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Thanks guys, I hooked it to the green wire and all went well. Appreciate the help.

Dec 21, 2008 | 05:56 PM

pc_2000

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From: Lutz, FL

Which tach did you get? I'm planning on getting myself one for Christmas as well. I'm thinking just a small one to mount on the column offset to the left a little.

Dec 22, 2008 | 06:48 PM

burninrubber2416

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Its a Sunpro tach its all I know. Its rpm range goes to 8000 rpm. It has a white face, and can select between 4, 6, or 8 cylinders. Nice tach I like it alot.

Dec 22, 2008 | 09:49 PM

pfogle

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From: Oak Harbor, OH

Is it the small one or the large one? I had the small one in a '92 E150 with 351w and I loved it. It was nice watching it jump to 4300rpm when you stood on it. I like the factory tach in my olds. Stand on it at 60mph and watch the tach hit 6k before it shifts. Then the damned thing is governed at 110mph so it never even shifts out of third gear before the computer shuts it down. I believe that car would run 160mph if you removed the software governor.