Tachometer issues December 31, 2017, 07:47:12 PM I'm new to the group and this is my first post.I'm having issues with the tach in my 1988 Thunderbird Sport 5.0 (buttstuffog gauges).I replaced the voltage regulator on my cluster and after that my tach barely moves.At 45mph instead of showing 1500rpm,its not even at 1000.I put the stock regulator back in and no difference even after resetting the computer.The TFI module is new as is the coil so they aren't the culprits.I figure its the wire going to the computer.The coil to cap wire itself is 3 years old (Ford 9mm Racing Wires)and the car runs alright otherwise for 219,000+ miles.I just dont feel like tearing into the computer,especially with no garage and freezing weather lol.If anyone has any idea what it could be,i would appreciate some input.I originally replaced the regulator because my oil gauge was always reading low and i had read an old regulator could give false readings.Because i know someone will ask why i tried changing it Quote Selected
Tachometer issues Reply #1 – December 31, 2017, 08:25:39 PM Make sure your connectors are seated tightly into the cluster. Quote Selected
Tachometer issues Reply #2 – January 01, 2018, 01:02:52 AM At 45mph you should be about 1200rpms, 1500 rpms would be about 60mph highway. Quote Selected
Tachometer issues Reply #3 – January 01, 2018, 02:11:31 PM Go back over your connections, snug the three nuts on back of cluster that make the connections to tach... As far as computer, has zero to do with tach operation... Quote Selected
Tachometer issues Reply #4 – January 01, 2018, 02:41:20 PM The 88 EVTM doesn't show the buttstuffog tach for the 5.0 sport.The Turbo Coupe buttstuffog tach does not use the IVR (instrument voltage regulator) or, as Turbocoupe50 says, the computer.Turbo Coupe cluster connector C285 uses pins 1, 16 and 12 for the tachPin 1 circuit #640 R/Y is power from fuse 16.Pin 16 circuit #11 DG/Y is from the Tach side of the coil.Pin 12 circuit #57 BK is ground.The Sport cluster connector has the same circuit numbers and color codes on pins 1, 16 and 12.My guess is it works the same as the Turbo Coupe.[COLOR="#FF0000"]OOPS!!![/COLOR][COLOR="#FF0000"][/COLOR] I put the red box on pin 17, it should be on pin 16 for the Turbo Coupe connector. Quote Selected
Tachometer issues Reply #5 – January 01, 2018, 03:17:15 PM Quote from: softtouch;464129The Sport cluster connector has the same circuit numbers and color codes on pins 1, 16 and 12.My guess is it works the same as the Turbo Coupe.Yep, I have a '88 Sport tach in my original TC cluster...If fact only differences in the ½ motor & Sport tach are one resistor and the faces...Note this is for '87 & '88, earlier Turbo Coupe tachs have entirely different circuitry... Quote Selected
Tachometer issues Reply #6 – January 01, 2018, 06:56:35 PM The only reason bring up the computer is because the yellow/green wire off the TFI runs to the relay off the computer.I had read elsewhere that if its making a bad connection (wire possibly exposed and grounding out)it can affect the rest of the electronics related to the ignition, which in turn sends the signal to the tachometer. Quote Selected
Tachometer issues Reply #7 – February 18, 2018, 10:02:16 AM I took the tach apart,cleaned everything up,and finally got it working properly Quote Selected
Topic: Tachometer issues (Read 1817 times)
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