Author Topic: 71 Boss Tach  (Read 3594 times)

Offline jatkinson

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71 Boss Tach
« on: December 06, 2022, 01:13:17 PM »
 We are putting the original distributor back in the car. The previous owner had changed it over to MSD. The tach worked with the MSD unit in it. However he did not use the MSD tach adapter.  The tach will not work with the stock distributor. Any ideas?
Thanks
1970 Metuchen Mach1 Medium Red 351C 4v Auto PB Shaker Black Interior

Offline J_Speegle

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Re: 71 Boss Tach
« Reply #1 on: December 06, 2022, 04:43:26 PM »
Never ran a MSD system but wonder if someone modified the tach internally. Like most Ford tachs they (if I recall correctly) were designed to work inline with the ignition power.

Hopefully someone else will know if there is a modification done to tachs to work with that aftermarket system or maybe check on one of the sites that does allot more with modifying these cars
Jeff Speegle

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Offline jwc66k

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Re: 71 Boss Tach
« Reply #2 on: December 06, 2022, 05:31:42 PM »
Like most Ford tachs they (if I recall correctly) were designed to work inline with the ignition power.
The 1971 Mustang Electrical Assembly Manual (AM0043) page 96 shows the tach wired "Like most Ford tachs -" - inline.
I sent my 66 8K RPM Rally Pac to Phil Severance for repair. Send me a PM and I'll give you his e-mail address and phone number.
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Offline midlife

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Re: 71 Boss Tach
« Reply #3 on: December 06, 2022, 10:05:57 PM »
The 1971 Mustang Electrical Assembly Manual (AM0043) page 96 shows the tach wired "Like most Ford tachs -" - inline.
I sent my 66 8K RPM Rally Pac to Phil Severance for repair. Send me a PM and I'll give you his e-mail address and phone number.
Jim
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Offline 67gtasanjose

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Re: 71 Boss Tach
« Reply #4 on: December 07, 2022, 06:32:22 AM »
I'll second the endorsement of Phil Severance.
+1
Phil has the components, experience and equipment to do it right the first time. Accurate results where previously my 67's tach was always off in calibration.
Richard Urch

1967 (11/2/66, S.J.) GTA Luxury Coupe, 289-4V w/Thermactor Emissions, C-4, Int./Ext. Decor +many options

2005 (04/05) GT Premium Convertible, Windveil Blue, Parchment Top w/Med. Parchment interior,  Roush Body Appointments

Offline jatkinson

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Re: 71 Boss Tach
« Reply #5 on: December 07, 2022, 05:18:39 PM »
Got the tach figured out I think. Does anyone know what the colour of the  resistance ignition wire ?
1970 Metuchen Mach1 Medium Red 351C 4v Auto PB Shaker Black Interior

Offline carlite65

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Re: 71 Boss Tach
« Reply #6 on: December 07, 2022, 05:19:54 PM »
should be a pink wire enclosed in a woven cloth sheath.
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Offline midlife

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Re: 71 Boss Tach
« Reply #7 on: December 07, 2022, 09:33:52 PM »
For 71 on up, the resistor wire changed to a red/green wire with rubber insulation.
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