Tach not working after new transmission install

M

machstang23

New Member

Apr 27, 2007

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Mar 14, 2008

#1

• Mar 14, 2008

• #1

I recently installed a new motor and tremec 3550 tansmission, and now my tach isn't working. What drives the tach? what did I forget to hook up that is causing my tach not to operate? I have made and double checked all my connections on the transmission, is there somethign under the hood I am forgetting? any advise would be greatly appreciated.

 

5.0Droptop

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Special Agent Mukity-Muck Whats in Charge Round Here

May 15, 2002

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Mar 14, 2008

#2

• Mar 14, 2008

• #2

Sounds like you stripped the tach gear. That will cost you.

 

5.0Droptop

...all those nights we shared, and you're a dude??

Special Agent Mukity-Muck Whats in Charge Round Here

May 15, 2002

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#3

• Mar 14, 2008

• #3

I was just playing. The tach signal is picked up from the neg coil wire. Did you add a MSD box or anything like that?

 

M

machstang23

New Member

Apr 27, 2007

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Mar 14, 2008

#4

• Mar 14, 2008

• #4

no, I didn't add a MSD box, but I did convert the car to mass air using the engine harness out ouf an 89 (mine is an 88) and I was told that everything was compatible, is there something I am missing or maybe a bad fuseable link?

 

5.0Droptop

...all those nights we shared, and you're a dude??

Special Agent Mukity-Muck Whats in Charge Round Here

May 15, 2002

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#5

• Mar 14, 2008

• #5

I cant say. When you go swapping a harness it could be anything.

 

5.0Droptop

...all those nights we shared, and you're a dude??

Special Agent Mukity-Muck Whats in Charge Round Here

May 15, 2002

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Mar 14, 2008

#6

• Mar 14, 2008

• #6

machstang, I would email jrichker he has all kinds of knowledge on wiring etc. He can link you to diagrams etc.
http://forums.stangnet.com/member.php?find=lastposter&t=742016

 

jrichker

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Mar 14, 2008

#7

• Mar 14, 2008

• #7

The Tach signal comes off the IDM output, pin 4 on the computer with a dark green/yellow wire...

Diagram courtesy of Tmoss & Stang&2birds


See the following website for some help from Tmoss (diagram designer) & Stang&2Birds (website host) for help on 88-95 wiring http://www.veryuseful.com/mustang/tech/engine/

Ignition switch wiring
http://www.veryuseful.com/mustang/tech/engine/images/IgnitionSwitchWiring.gif

Fuel pump, alternator, ignition & A/C wiring
http://www.veryuseful.com/mustang/tech/engine/images/fuel-alt-links-ign-ac.gif

Computer, actuator & sensor wiring
http://www.veryuseful.com/mustang/tech/engine/images/88-91_5.0_EEC_Wiring_Diagram.gif

Fuse panel layout
http://www.veryuseful.com/mustang/tech/engine/images/MustangFuseBox.gif

Vacuum routing
http://www.veryuseful.com/mustang/tech/engine/images/mustangFoxFordVacuumDiagram.jpg

 

5.0Droptop

...all those nights we shared, and you're a dude??

Special Agent Mukity-Muck Whats in Charge Round Here

May 15, 2002

1,785

1,130

233

Indiana

Mar 14, 2008

#8

• Mar 14, 2008

• #8

See I told you Jrichker is the man with the diagram!! Now you know where to start, Pin #4 at the plug, it appears to go to the TFI module plug to dizzy. It looks like it may have a resistor of some sort inline 5.9" from the main plug.